draft-ietf-tsvwg-emergency-rsvp-00.txt | draft-ietf-tsvwg-emergency-rsvp-01.txt | |||
---|---|---|---|---|
RSVP Extensions for Emergency Services October 2006 | RSVP Extensions for Emergency Services January 2007 | |||
Internet Draft Francois Le Faucheur | Internet Draft Francois Le Faucheur | |||
James Polk | James Polk | |||
Cisco Systems, Inc. | Cisco Systems, Inc. | |||
Ken Carlberg | Ken Carlberg | |||
G11 | G11 | |||
draft-ietf-tsvwg-emergency-rsvp-00.txt | draft-ietf-tsvwg-emergency-rsvp-01.txt | |||
Expires: April 2007 October 2006 | Expires: July 2007 January 2007 | |||
RSVP Extensions for Emergency Services | Resource ReSerVation Protovol (RSVP) Extensions for Emergency | |||
Services | ||||
Status of this Memo | Status of this Memo | |||
By submitting this Internet-Draft, each author represents that any | By submitting this Internet-Draft, each author represents that any | |||
applicable patent or other IPR claims of which he or she is aware | applicable patent or other IPR claims of which he or she is aware | |||
have been or will be disclosed, and any of which he or she becomes | have been or will be disclosed, and any of which he or she becomes | |||
aware will be disclosed, in accordance with Section 6 of BCP 79. | aware will be disclosed, in accordance with Section 6 of BCP 79. | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF), its areas, and its working groups. Note that other | Task Force (IETF), its areas, and its working groups. Note that other | |||
skipping to change at page 2, line 5 | skipping to change at page 2, line 5 | |||
An Emergency Telecommunications Service (ETS) requires the ability to | An Emergency Telecommunications Service (ETS) requires the ability to | |||
provide an elevated probability of session establishment to an | provide an elevated probability of session establishment to an | |||
authorized user in times of network congestion (typically, during a | authorized user in times of network congestion (typically, during a | |||
crisis). When supported over the Internet Protocol suite, this may be | crisis). When supported over the Internet Protocol suite, this may be | |||
facilitated through a network layer admission control solution, which | facilitated through a network layer admission control solution, which | |||
supports prioritized access to resources (e.g., bandwidth). These | supports prioritized access to resources (e.g., bandwidth). These | |||
resources may be explicitly set aside for emergency services, or they | resources may be explicitly set aside for emergency services, or they | |||
may be shared with other sessions. | may be shared with other sessions. | |||
RSVP Extensions for Emergency Services October 2006 | RSVP Extensions for Emergency Services January 2007 | |||
This document specifies RSVP extensions that can be used to support | This document specifies RSVP extensions that can be used to support | |||
such an admission priority capability at the network layer. Note that | such an admission priority capability at the network layer. Note that | |||
these extensions represent one possible solution component in | these extensions represent one possible solution component in | |||
satisfying ETS requirements. Other solution components, or other | satisfying ETS requirements. Other solution components, or other | |||
solutions, are outside the scope of this document. | solutions, are outside the scope of this document. | |||
Copyright Notice | Copyright Notice | |||
Copyright (C) The Internet Society (2006). | Copyright (C) The Internet Society (2007). | |||
Specification of Requirements | Specification of Requirements | |||
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | In this document, the key words "MUST", "MUST NOT", "REQUIRED", | |||
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and | |||
document are to be interpreted as described in [RFC2119]. | "OPTIONAL" in this document are to be interpreted as described in | |||
[KEYWORDS] and indicate requirement levels for compliant | ||||
implementations. | ||||
Table of Contents | Table of Contents | |||
1. Introduction...................................................2 | 1. Introduction...................................................3 | |||
1.1. Related Work...............................................3 | 1.1. Related Technical Documents................................3 | |||
1.2. Terminology................................................4 | 1.2. Terminology................................................4 | |||
1.3. Changes from previous versions.............................4 | 1.3. Changes from previous versions.............................5 | |||
2. Overview of RSVP extensions and Operations.....................5 | 2. Overview of RSVP extensions and Operations.....................6 | |||
2.1. Operations of Admission Priority..........................8 | 2.1. Operations of Admission Priority..........................8 | |||
3. New Policy Elements............................................8 | 3. New Policy Elements............................................8 | |||
3.1. Admission Priority Policy Element.........................9 | 3.1. Admission Priority Policy Element.........................9 | |||
3.1.1. Admission Priority Merging Rules 10 | 3.1.1. Admission Priority Merging Rules 10 | |||
3.2. Application-Level Resource Priority Policy Element.......10 | 3.2. Application-Level Resource Priority Policy Element.......11 | |||
3.2.1. Application-Level Resource Priority Modifying and | 3.2.1. Application-Level Resource Priority Modifying and | |||
Merging Rules 12 | Merging Rules 12 | |||
4. Security Considerations.......................................12 | 4. Security Considerations.......................................12 | |||
5. IANA Considerations...........................................12 | 4.1. Use of RSVP Authentication...............................13 | |||
6. Acknowledgments...............................................13 | 4.2. Use of INTEGRITY object within the POLICY_DATA object....14 | |||
7. Normative References..........................................13 | 5. IANA Considerations...........................................14 | |||
8. Informative References........................................13 | 6. Acknowledgments...............................................15 | |||
7. Normative References..........................................15 | ||||
8. Informative References........................................16 | ||||
Appendix A: Examples of Bandwidth Allocation Model for Admission | Appendix A: Examples of Bandwidth Allocation Model for Admission | |||
Priority.........................................................14 | Priority.........................................................16 | |||
A.1 Admission Priority with Maximum Allocation Model (MAM)......14 | A.1 Admission Priority with Maximum Allocation Model (MAM)......17 | |||
A.2 Admission Priority with Russian Dolls Model (RDM)...........18 | A.2 Admission Priority with Russian Dolls Model (RDM)...........20 | |||
A.3 Admission Priority with Priority Bypass Model (PBM).........20 | A.3 Admission Priority with Priority Bypass Model (PBM).........23 | |||
Appendix B: Example Usages of RSVP Extensions....................23 | Appendix B: Example Usages of RSVP Extensions....................26 | |||
Authors' Address.................................................25 | Authors' Address.................................................27 | |||
1. Introduction | RSVP Extensions for Emergency Services January 2007 | |||
RSVP Extensions for Emergency Services October 2006 | 1. Introduction | |||
[EMERG-RQTS] and [EMERG-TEL] detail requirements for an Emergency | [EMERG-RQTS] and [EMERG-TEL] detail requirements for an Emergency | |||
Telecommunications Service (ETS), which is an umbrella term | Telecommunications Service (ETS), which is an umbrella term | |||
identifying those networks and specific services used to support | identifying those networks and specific services used to support | |||
emergency communications. An underlying goal of these documents is to | emergency communications. An underlying goal of these documents is to | |||
present requirements that elevate the probability of session | present requirements that elevate the probability of session | |||
establishment from an authorized user in times of network congestion | establishment from an authorized user in times of network congestion | |||
(presumably because of a crisis condition). In some extreme cases, | (presumably because of a crisis condition). In some extreme cases, | |||
the requirement for this probability may reach 100%, but that is a | the requirement for this probability may reach 100%, but that is a | |||
topic subject to policy and most likely local regulation (the latter | topic subject to policy and most likely local regulation (the latter | |||
being outside the scope of this document). | being outside the scope of this document). | |||
Solutions to meet this requirement for elevated session establishment | Solutions to meet this requirement for elevated session establishment | |||
probability may involve session layer capabilities prioritizing | probability may involve session layer capabilities prioritizing | |||
access to resources controlled by the session control function. As an | access to resources controlled by the session control function. As an | |||
example, entities involved in session control (such as SIP user | example, entities involved in session control (such as SIP user | |||
agents, when SIP is the session control protocol in use) can | agents, when the Session Initiation Protocol, SIP [SIP], is the | |||
influence their treatment of session establishment requests (such as | session control protocol in use) can influence their treatment of | |||
SIP requests). This may include the ability to "queue" call requests | session establishment requests (such as SIP requests). This may | |||
when those can not be immediately honored (in some cases with the | include the ability to "queue" call requests when those can not be | |||
notion of "bumping", or "displacement", of less important call | immediately honored (in some cases with the notion of "bumping", or | |||
request from that queue). It may include additional mechanisms such | "displacement", of less important call request from that queue). It | |||
as exemption from certain network management controls, and alternate | may include additional mechanisms such as exemption from certain | |||
routing. | network management controls, and alternate routing. | |||
Solutions to meet the requirement for elevated session establishment | Solutions to meet the requirement for elevated session establishment | |||
probability may also take advantage of network layer admission | probability may also take advantage of network layer admission | |||
control mechanisms supporting admission priority. Networks usually | control mechanisms supporting admission priority. Networks usually | |||
have engineered capacity limits that characterize the maximum load | have engineered capacity limits that characterize the maximum load | |||
that can be handled (say, on any given link) for a class of traffic | that can be handled (say, on any given link) for a class of traffic | |||
while satisfying the quality of service requirements of that traffic | while satisfying the quality of service requirements of that traffic | |||
class. Admission priority may involve setting aside some network | class. Admission priority may involve setting aside some network | |||
resources (e.g. bandwidth) out of the engineered capacity limits for | resources (e.g. bandwidth) out of the engineered capacity limits for | |||
the emergency services only. Or alternatively, it may involve | the emergency services only. Or alternatively, it may involve | |||
allowing the emergency related sessions to seize additional resources | allowing the emergency related sessions to seize additional resources | |||
beyond the engineered capacity limits applied to normal calls. | beyond the engineered capacity limits applied to normal calls. | |||
Note: Below, this document references several examples of IP | Note: Below, this document references several examples of IP | |||
telephony and its use of "calls", which is one form of the term | telephony and its use of "calls", which is one form of the term | |||
"sessions" (Video over IP and Instant Messaging being other examples | "sessions" (Video over IP and Instant Messaging being other examples | |||
that rely on session establishment). For the sake of simplicity, we | that rely on session establishment). For the sake of simplicity, we | |||
shall use the widely known term "call" for the remainder of this | shall use the widely known term "call" for the remainder of this | |||
document. | document. | |||
1.1. Related Work | 1.1. Related Technical Documents | |||
RSVP Extensions for Emergency Services January 2007 | ||||
[EMERG-IMP] is patterned after [ITU.I.225] and describes an example | [EMERG-IMP] is patterned after [ITU.I.225] and describes an example | |||
of one type of prioritized network layer admission control procedure | of one type of prioritized network layer admission control procedure | |||
that may be used for emergency services operating over an IP network | that may be used for emergency services operating over an IP network | |||
infrastructure. It discusses initial call set up, as well as | infrastructure. It discusses initial call set up, as well as | |||
RSVP Extensions for Emergency Services October 2006 | ||||
operations after call establishment through maintenance of a | operations after call establishment through maintenance of a | |||
continuing call model of the status of all calls. [EMERG-IMP] also | continuing call model of the status of all calls. [EMERG-IMP] also | |||
describes how these network layer admission control procedures can be | describes how these network layer admission control procedures can be | |||
realized using the Resource reSerVation Protocol [RSVP] along with | realized using the Resource reSerVation Protocol [RSVP] along with | |||
its associated protocol suite and extensions, including those for | its associated protocol suite and extensions, including those for | |||
policy based admission control ([FW-POLICY], [RSVP-POLICY]), for user | policy based admission control ([FW-POLICY], [RSVP-POLICY]), for user | |||
authentication and authorization ([RSVP-ID]) and for integrity and | authentication and authorization ([RSVP-ID]) and for integrity and | |||
authentication of RSVP messages ([RSVP-CRYPTO-1], [RSVP-CRYPTO-2]). | authentication of RSVP messages ([RSVP-CRYPTO-1], [RSVP-CRYPTO-2]). | |||
Furthermore, [EMERG-IMP] describes how the RSVP Signaled Preemption | Furthermore, [EMERG-IMP] describes how the RSVP Signaled Preemption | |||
skipping to change at page 4, line 52 | skipping to change at page 5, line 5 | |||
- Local Policy Decision Point (LPDP): PDP local to the network | - Local Policy Decision Point (LPDP): PDP local to the network | |||
element | element | |||
- Policy Enforcement Point (PEP): The point where the policy | - Policy Enforcement Point (PEP): The point where the policy | |||
decisions are actually enforced. | decisions are actually enforced. | |||
- Policy Ignorant Node (PIN): A network element that does not | - Policy Ignorant Node (PIN): A network element that does not | |||
explicitly support policy control using the mechanisms defined in | explicitly support policy control using the mechanisms defined in | |||
[FW-POLICY]. | [FW-POLICY]. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
1.3. Changes from previous versions | 1.3. Changes from previous versions | |||
[Note to RFC Editor: This section is to be removed before | ||||
publication] | ||||
RSVP Extensions for Emergency Services October 2006 | Changes from ietf-tsvwg-emergency-rsvp-00 to ietf-tsvwg- | |||
emergency-rsvp-01 | ||||
The most significant changes are: | ||||
o editorial change (correction in description of | ||||
"Take highest priority" in section 3.1.1). | ||||
o expanded Security Considerations section | ||||
Changes from lefaucheur-rsvp-emergency-01 to ietf-tsvwg-rsvp- | Changes from lefaucheur-rsvp-emergency-01 to ietf-tsvwg-rsvp- | |||
emergency-00 | emergency-00 | |||
The most significant change is: | The most significant change is: | |||
o Extended the Admission Priority field from 3 to 8 bits and | o Extended the Admission Priority field from 3 to 8 bits and | |||
inverted the encoding order, in particular for better | inverted the encoding order, in particular for better | |||
alignment with NSIS Qspec. | alignment with NSIS Qspec. | |||
skipping to change at page 5, line 38 | skipping to change at page 6, line 5 | |||
ALRP Policy Element | ALRP Policy Element | |||
o Added a 2nd appendix providing examples of RSVP extensions | o Added a 2nd appendix providing examples of RSVP extensions | |||
usage | usage | |||
Changes from lefaucheur-rsvp-emergency-00 to lefaucheur-rsvp- | Changes from lefaucheur-rsvp-emergency-00 to lefaucheur-rsvp- | |||
emergency-01 | emergency-01 | |||
The most significant changes were: | The most significant changes were: | |||
RSVP Extensions for Emergency Services January 2007 | ||||
o adding a second RSVP Policy Element that contains the | o adding a second RSVP Policy Element that contains the | |||
application-level resource priority requirements (for example | application-level resource priority requirements (for example | |||
as communicated in the SIP Resource-Priority Header) for | as communicated in the SIP Resource-Priority Header) for | |||
scenarios where priority calls transits through multiple | scenarios where priority calls transits through multiple | |||
administrative domains. | administrative domains. | |||
o adding description of a third bandwidth allocation model | o adding description of a third bandwidth allocation model | |||
example: the Priority Bypass Model | example: the Priority Bypass Model | |||
o adding discussion on policies for mapping the various | o adding discussion on policies for mapping the various | |||
bandwidth allocation model over the engineered capacity limits. | bandwidth allocation model over the engineered capacity limits. | |||
2. Overview of RSVP extensions and Operations | 2. Overview of RSVP extensions and Operations | |||
RSVP Extensions for Emergency Services October 2006 | ||||
Let us consider the case where a call requiring ETS type service is | Let us consider the case where a call requiring ETS type service is | |||
to be established, and more specifically that the preference to be | to be established, and more specifically that the preference to be | |||
granted to this call is in terms of network layer "admission | granted to this call is in terms of network layer "admission | |||
priority" (as opposed to preference granted through preemption of | priority" (as opposed to preference granted through preemption of | |||
existing calls). By "admission priority" we mean allowing that | existing calls). By "admission priority" we mean allowing that | |||
priority call to seize network layer resources from the engineered | priority call to seize network layer resources from the engineered | |||
capacity that have been set-aside and not made available to normal | capacity that have been set-aside and not made available to normal | |||
calls, or alternatively by allowing that call to seize additional | calls, or alternatively by allowing that call to seize additional | |||
resources beyond the engineered capacity limits applied to normal | resources beyond the engineered capacity limits applied to normal | |||
calls. | calls. | |||
skipping to change at page 6, line 40 | skipping to change at page 7, line 4 | |||
end-devices involved in the upper-layer session establishment simply | end-devices involved in the upper-layer session establishment simply | |||
need to copy the application-level resource priority requirements | need to copy the application-level resource priority requirements | |||
(e.g. as communicated in SIP Resource-Priority Header) inside the new | (e.g. as communicated in SIP Resource-Priority Header) inside the new | |||
RSVP Application-Level Resource-Priority Policy Element defined in | RSVP Application-Level Resource-Priority Policy Element defined in | |||
this document. | this document. | |||
Conveying the application-level resource priority requirements inside | Conveying the application-level resource priority requirements inside | |||
the RSVP message allows this application level requirement to be | the RSVP message allows this application level requirement to be | |||
mapped/remapped into a different RSVP "admission priority" at every | mapped/remapped into a different RSVP "admission priority" at every | |||
administrative domain boundary based on the policy applicable in that | administrative domain boundary based on the policy applicable in that | |||
RSVP Extensions for Emergency Services January 2007 | ||||
domain. In a typical model (see [FW-POLICY]) where PDPs control PEPs | domain. In a typical model (see [FW-POLICY]) where PDPs control PEPs | |||
at the periphery of the policy domain (e.g., in border routers), PDPs | at the periphery of the policy domain (e.g., in border routers), PDPs | |||
would interpret the RSVP Application-Level Resource-Priority Policy | would interpret the RSVP Application-Level Resource-Priority Policy | |||
Element and map the requirement of the emergency session into an RSVP | Element and map the requirement of the emergency session into an RSVP | |||
"admission priority" level. Then, PDPs would convey this information | "admission priority" level. Then, PDPs would convey this information | |||
inside the new Admission Priority Policy Element defined in this | inside the new Admission Priority Policy Element defined in this | |||
document. This way, the RSVP admission priority can be communicated | document. This way, the RSVP admission priority can be communicated | |||
to downstream PEPs (ie RSVP Routers) of the same policy domain, which | to downstream PEPs (ie RSVP Routers) of the same policy domain, which | |||
have LPDPs but no controlling PDP. In turn, this means the necessary | have LPDPs but no controlling PDP. In turn, this means the necessary | |||
RSVP Admission priority can be enforced at every RSVP hop, including | RSVP Admission priority can be enforced at every RSVP hop, including | |||
all the (many) hops which do not have any understanding of | all the (many) hops which do not have any understanding of | |||
Application-Level Resource-Priority semantics. | Application-Level Resource-Priority semantics. | |||
As an example of operation across multiple administrative domains, a | As an example of operation across multiple administrative domains, a | |||
first domain might decide to provide network layer admission priority | first domain might decide to provide network layer admission priority | |||
to calls of a given Application Level Resource Priority and map it | to calls of a given Application Level Resource Priority and map it | |||
RSVP Extensions for Emergency Services October 2006 | ||||
into a high RSVP admission control priority inside the Admission | into a high RSVP admission control priority inside the Admission | |||
Priority Policy Element; while a second domain may decide to not | Priority Policy Element; while a second domain may decide to not | |||
provide admission priority to calls of this same Application Level | provide admission priority to calls of this same Application Level | |||
Resource Priority and hence map it into a low RSVP admission control | Resource Priority and hence map it into a low RSVP admission control | |||
priority. | priority. | |||
As another example of operation across multiple administrative | As another example of operation across multiple administrative | |||
domains, we can consider the case where the resource priority header | domains, we can consider the case where the resource priority header | |||
enumerates several namespaces, as explicitly allowed by [SIP- | enumerates several namespaces, as explicitly allowed by [SIP- | |||
PRIORITY], for support of scenarios where calls traverse multiple | PRIORITY], for support of scenarios where calls traverse multiple | |||
skipping to change at page 7, line 40 | skipping to change at page 8, line 4 | |||
Mapping/remapping by PDPs may also be applied to boundaries between | Mapping/remapping by PDPs may also be applied to boundaries between | |||
various signaling protocols, such as those advanced by the NSIS | various signaling protocols, such as those advanced by the NSIS | |||
working group. | working group. | |||
As can be observed, the framework described above for | As can be observed, the framework described above for | |||
mapping/remapping application level resource priority requirements | mapping/remapping application level resource priority requirements | |||
into an RSVP admission priority can also be used together with [RSVP- | into an RSVP admission priority can also be used together with [RSVP- | |||
PREEMP] for mapping/remapping application level resource priority | PREEMP] for mapping/remapping application level resource priority | |||
requirements into an RSVP preemption priority (when preemption is | requirements into an RSVP preemption priority (when preemption is | |||
indeed needed). In that case, when processing the RSVP Application- | indeed needed). In that case, when processing the RSVP Application- | |||
RSVP Extensions for Emergency Services January 2007 | ||||
Level Resource-Priority Policy Element, the PDPs at boundaries | Level Resource-Priority Policy Element, the PDPs at boundaries | |||
between administrative domains (or between various QoS signaling | between administrative domains (or between various QoS signaling | |||
protocols) can map it into an RSVP "preemption priority" information. | protocols) can map it into an RSVP "preemption priority" information. | |||
This Preemption priority information comprises a setup preemption | This Preemption priority information comprises a setup preemption | |||
level and a defending preemption priority level. This preemption | level and a defending preemption priority level. This preemption | |||
priority information can then be encoded inside the Preemption | priority information can then be encoded inside the Preemption | |||
Priority Policy Element of [RSVP-PREEMP] and thus, can be taken into | Priority Policy Element of [RSVP-PREEMP] and thus, can be taken into | |||
account at every RSVP-enabled network hop as discussed [EMERG-IMP]. | account at every RSVP-enabled network hop as discussed [EMERG-IMP]. | |||
Appendix B provides examples of various hypothetical policies for | Appendix B provides examples of various hypothetical policies for | |||
emergency call handling, some of them involving admission priority, | emergency call handling, some of them involving admission priority, | |||
some of them involving both admission priority and preemption | some of them involving both admission priority and preemption | |||
priority. Appendix B also identifies how the Application-Level | priority. Appendix B also identifies how the Application-Level | |||
Resource Priority need to be mapped into RSVP policy elements by the | Resource Priority need to be mapped into RSVP policy elements by the | |||
PDPs to realize these policies. | PDPs to realize these policies. | |||
RSVP Extensions for Emergency Services October 2006 | ||||
2.1. Operations of Admission Priority | 2.1. Operations of Admission Priority | |||
The RSVP Admission Priority policy element defined in this document | The RSVP Admission Priority policy element defined in this document | |||
allows admission bandwidth to be allocated preferentially to an | allows admission bandwidth to be allocated preferentially to an | |||
authorized priority service. Multiple models of bandwidth allocation | authorized priority service. Multiple models of bandwidth allocation | |||
MAY be used to that end. | MAY be used to that end. | |||
A number of bandwidth allocation models have been defined in the IETF | A number of bandwidth allocation models have been defined in the IETF | |||
for allocation of bandwidth across different classes of traffic | for allocation of bandwidth across different classes of traffic | |||
trunks in the context of Diffserv-aware MPLS Traffic Engineering. | trunks in the context of Diffserv-aware MPLS Traffic Engineering. | |||
skipping to change at page 8, line 41 | skipping to change at page 9, line 5 | |||
describes the various components that participate in policy decision | describes the various components that participate in policy decision | |||
making (i.e., PDP, PEP and LPDP). | making (i.e., PDP, PEP and LPDP). | |||
As described in section 2 of the present document, the Application- | As described in section 2 of the present document, the Application- | |||
Level Resource Priority Policy Element and the Admission Priority | Level Resource Priority Policy Element and the Admission Priority | |||
Policy Element serve different roles in this framework: | Policy Element serve different roles in this framework: | |||
- the Application-Level Resource Priority Policy Element conveys | - the Application-Level Resource Priority Policy Element conveys | |||
application level information and is processed by PDPs | application level information and is processed by PDPs | |||
RSVP Extensions for Emergency Services January 2007 | ||||
- the emphasis of Admission Priority Policy Element is to be | - the emphasis of Admission Priority Policy Element is to be | |||
simple, stateless, and light-weight such that it can be | simple, stateless, and light-weight such that it can be | |||
processed internally within a node's LPDP. It can then be | processed internally within a node's LPDP. It can then be | |||
enforced internally within a node's PEP. It is set by PDPs | enforced internally within a node's PEP. It is set by PDPs | |||
based on processing of the Application-Level Resource Priority | based on processing of the Application-Level Resource Priority | |||
Policy Element. | Policy Element. | |||
[RSVP-POLICY] defines extensions for supporting generic policy based | [RSVP-POLICY] defines extensions for supporting generic policy based | |||
admission control in RSVP. These extensions include the standard | admission control in RSVP. These extensions include the standard | |||
format of POLICY_DATA objects and a description of RSVP handling of | format of POLICY_DATA objects and a description of RSVP handling of | |||
policy events. | policy events. | |||
The POLICY_DATA object contains one or more of Policy Elements, each | The POLICY_DATA object contains one or more of Policy Elements, each | |||
representing a different (and perhaps orthogonal) policy. As an | representing a different (and perhaps orthogonal) policy. As an | |||
RSVP Extensions for Emergency Services October 2006 | ||||
example, [RSVP-PREEMP] specifies the Preemption Priority Policy | example, [RSVP-PREEMP] specifies the Preemption Priority Policy | |||
Element. | Element. | |||
This document defines two new Policy Elements called: | This document defines two new Policy Elements called: | |||
- the Admission Priority Policy Element | - the Admission Priority Policy Element | |||
- the Application-Level Resource Priority Policy Element | - the Application-Level Resource Priority Policy Element | |||
3.1. Admission Priority Policy Element | 3.1. Admission Priority Policy Element | |||
The format of the Admission Priority policy element is as follows: | The format of the Admission Priority policy element is as follows: | |||
skipping to change at page 9, line 39 | skipping to change at page 10, line 4 | |||
P-Type: 16 bits | P-Type: 16 bits | |||
ADMISSION_PRI = To be allocated by IANA | ADMISSION_PRI = To be allocated by IANA | |||
(see "IANA Considerations" section) | (see "IANA Considerations" section) | |||
Flags: Reserved (MUST be set to zero on transmit and ignored on | Flags: Reserved (MUST be set to zero on transmit and ignored on | |||
receive) | receive) | |||
Merge Strategy: 8 bit (only applicable to multicast flows) | Merge Strategy: 8 bit (only applicable to multicast flows) | |||
1 Take priority of highest QoS | 1 Take priority of highest QoS | |||
2 Take highest priority | 2 Take highest priority | |||
RSVP Extensions for Emergency Services January 2007 | ||||
3 Force Error on heterogeneous merge | 3 Force Error on heterogeneous merge | |||
Error code: 8 bits (only applicable to multicast flows) | Error code: 8 bits (only applicable to multicast flows) | |||
0 NO_ERROR Value used for regular ADMISSION_PRI elements | 0 NO_ERROR Value used for regular ADMISSION_PRI elements | |||
2 HETEROGENEOUS This element encountered heterogeneous merge | 2 HETEROGENEOUS This element encountered heterogeneous merge | |||
Reserved: 8 bits | Reserved: 8 bits | |||
Always 0. | Always 0. | |||
Adm. Priority (Admission Priority): 8 bits (unsigned) | Adm. Priority (Admission Priority): 8 bits (unsigned) | |||
The admission control priority of the flow, in terms of access | The admission control priority of the flow, in terms of access | |||
to network bandwidth in order to provide higher probability of | to network bandwidth in order to provide higher probability of | |||
call completion to selected flows. Higher values represent | call completion to selected flows. Higher values represent | |||
higher Priority. | higher Priority. | |||
Bandwidth allocation models such as those described in Appendix | Bandwidth allocation models such as those described in Appendix | |||
RSVP Extensions for Emergency Services October 2006 | ||||
A are to be used by the RSVP router to achieve such increased | A are to be used by the RSVP router to achieve such increased | |||
probability of call completion. The admission priority value | probability of call completion. The admission priority value | |||
effectively indicates which bandwidth constraint(s) of the | effectively indicates which bandwidth constraint(s) of the | |||
bandwidth constraint model in use is(are) applicable to | bandwidth constraint model in use is(are) applicable to | |||
admission of this RSVP reservation. | admission of this RSVP reservation. | |||
Reserved: 16 bits | Reserved: 16 bits | |||
Always 0. | Always 0. | |||
Note that the Admission Priority Policy Element does NOT indicate | Note that the Admission Priority Policy Element does NOT indicate | |||
skipping to change at page 10, line 40 | skipping to change at page 11, line 4 | |||
applicable to multicast, this section also only applies to multicast | applicable to multicast, this section also only applies to multicast | |||
sessions. | sessions. | |||
The rules for merging Admission Priority Policy Elements are the same | The rules for merging Admission Priority Policy Elements are the same | |||
as those defined in [RSVP-PREEMP] for merging Preemption Priority | as those defined in [RSVP-PREEMP] for merging Preemption Priority | |||
Policy Elements. In particular, the following merging strategies are | Policy Elements. In particular, the following merging strategies are | |||
supported: | supported: | |||
- Take priority of highest QoS | - Take priority of highest QoS | |||
- Take highest priority | - Take highest priority | |||
- Force Error on heterogeneous merge. | - Force Error on heterogeneous merge. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
The only difference with [RSVP-PREEMP] is that this document does not | The only difference with [RSVP-PREEMP] is that this document does not | |||
recommend any merge strategies for Admission Priority while [RSVP- | recommend any merge strategies for Admission Priority while [RSVP- | |||
PREEMP] recommends the first of these merge strategies for Preemption | PREEMP] recommends the first of these merge strategies for Preemption | |||
Priority. | Priority. | |||
Note that with the Admission Priority, "Take Highest Priority" | Note that with the Admission Priority (as is the case with the | |||
translates into "take the lowest numerical value", while with the | Preemption Priority), "Take highest priority" translates into "take | |||
Preemption Priority it translates into "take the highest numerical | the highest numerical value". | |||
value". | ||||
3.2. Application-Level Resource Priority Policy Element | 3.2. Application-Level Resource Priority Policy Element | |||
The format of the Application-Level Resource Priority policy element | The format of the Application-Level Resource Priority policy element | |||
is as follows: | is as follows: | |||
+-------------+-------------+-------------+-------------+ | +-------------+-------------+-------------+-------------+ | |||
RSVP Extensions for Emergency Services October 2006 | ||||
| Length | P-Type = APP_RESOURCE_PRI | | | Length | P-Type = APP_RESOURCE_PRI | | |||
+-------------+-------------+-------------+-------------+ | +-------------+-------------+-------------+-------------+ | |||
// ALRP List // | // ALRP List // | |||
+---------------------------+---------------------------+ | +---------------------------+---------------------------+ | |||
Length: The length of the policy element (including the Length and P- | Length: The length of the policy element (including the Length and P- | |||
Type) is in number of octets (MUST be a multiple of 4) and | Type) is in number of octets (MUST be a multiple of 4) and | |||
indicates the end of the ALRP list. | indicates the end of the ALRP list. | |||
P-Type: 16 bits | P-Type: 16 bits | |||
skipping to change at page 11, line 40 | skipping to change at page 12, line 5 | |||
represents the position of the namespace in the "Resource- | represents the position of the namespace in the "Resource- | |||
Priority Namespace" IANA registry, starting with 0. Creation | Priority Namespace" IANA registry, starting with 0. Creation | |||
of this registry has been requested to IANA in [SIP- | of this registry has been requested to IANA in [SIP- | |||
PRIORITY]. | PRIORITY]. | |||
For example, as "drsn", "dsn", "q735", "ets" and "wps" are | For example, as "drsn", "dsn", "q735", "ets" and "wps" are | |||
currently the first, second, third, fourth and fifth | currently the first, second, third, fourth and fifth | |||
namespaces defined in the "Resource-Priority Namespace" | namespaces defined in the "Resource-Priority Namespace" | |||
registry, those are respectively encoded as value 0, 1, 2, 3 | registry, those are respectively encoded as value 0, 1, 2, 3 | |||
and 4. | and 4. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
ALRP Priority: (Application-Level Resource Priority Priority): | ALRP Priority: (Application-Level Resource Priority Priority): | |||
8 bits (unsigned) | 8 bits (unsigned) | |||
Contains the priority value within the namespace of the | Contains the priority value within the namespace of the | |||
application-level resource priority. This is encoded as a | application-level resource priority. This is encoded as a | |||
numerical value which represents the priority defined in the | numerical value which represents the priority defined in the | |||
"Resource-Priority Namespace" IANA registry for the | "Resource-Priority Namespace" IANA registry for the | |||
considered namespace, starting from 0 for the highest | considered namespace, starting from 0 for the highest | |||
priority and increasing as priority decreases. | priority and increasing as priority decreases. | |||
For example, as "flash-override", "flash", "immediate", | For example, as "flash-override", "flash", "immediate", | |||
"priority" and "routine" are the priorities in decreasing | "priority" and "routine" are the priorities in decreasing | |||
order of priority registered for the "dsn" namespace, those | order of priority registered for the "dsn" namespace, those | |||
are respectively encoded as value 0, 1, 2, 3 and 4. As | are respectively encoded as value 0, 1, 2, 3 and 4. As | |||
another example, as "flash-override-override", "flash- | another example, as "flash-override-override", "flash- | |||
override", "flash", "immediate", "priority" and "routine" | override", "flash", "immediate", "priority" and "routine" | |||
are the priorities in decreasing order of priority | are the priorities in decreasing order of priority | |||
RSVP Extensions for Emergency Services October 2006 | ||||
registered for the "drsn" namespace, those are respectively | registered for the "drsn" namespace, those are respectively | |||
encoded as value 0, 1, 2, 3, 4 and 5. | encoded as value 0, 1, 2, 3, 4 and 5. | |||
Reserved: 16 bits | Reserved: 16 bits | |||
Always 0. | Always 0. | |||
3.2.1. | 3.2.1. | |||
Application-Level Resource Priority Modifying and Merging Rules | Application-Level Resource Priority Modifying and Merging Rules | |||
When POLICY_DATA objects are protected by integrity, LPDPs should not | When POLICY_DATA objects are protected by integrity, LPDPs should not | |||
skipping to change at page 12, line 36 | skipping to change at page 12, line 51 | |||
all the ALRPs appearing in the ALRP List of an incoming | all the ALRPs appearing in the ALRP List of an incoming | |||
APP_RESOURCE_PR element. A given ALRP MUST NOT appear more than | APP_RESOURCE_PR element. A given ALRP MUST NOT appear more than | |||
once. In other words, the outgoing ALRP List is the reunion of | once. In other words, the outgoing ALRP List is the reunion of | |||
the incoming ARLP Lists that are merged. | the incoming ARLP Lists that are merged. | |||
As merging is only applicable to Multicast, this rule only applies to | As merging is only applicable to Multicast, this rule only applies to | |||
Multicast sessions. | Multicast sessions. | |||
4. Security Considerations | 4. Security Considerations | |||
The integrity of ADMISSION_PRI and APP_RESOURCE_PRI is guaranteed, as | The ADMISSION_PRI and APP_RESOURCE_PRI are Policy Elements that can | |||
any other policy element, by the encapsulation into a Policy Data | be signaled by RSVP through encapsulation in a Policy Data object as | |||
object [RSVP-POLICY]. The two optional security mechanisms discussed | defined in [RSVP-POLICY]. Therefore, like any other Policy Elements, | |||
in section 6 of [RSVP-POLICY] can be used to protect the | their integrity can be protected as discussed in section 6 of [RSVP- | |||
ADMISSION_PRI and APP_RESOURCE_PRI policy elements. | ||||
RSVP Extensions for Emergency Services January 2007 | ||||
POLICY] by two optional security mechanisms. The first mechanism | ||||
relies on RSVP Authentication as specified in [RSVP-CRYPTO-1] and | ||||
[RSVP-CRYPTO-2] to provide a chain of trust when all RSVP nodes are | ||||
policy capable. The second mechanism relies on the INTEGRITY object | ||||
within the POLICY_DATA object to guarantee integrity between RSVP | ||||
Policy Enforcement Points (PEPs) that are not RSVP neighbors. | ||||
4.1. Use of RSVP Authentication | ||||
[RSVP-CRYPTO-1] discusses several approaches for distribution of keys | ||||
to be used for RSVP Authentication. First, the RSVP Authentication | ||||
shared keys can be distributed manually. This is the base option and | ||||
its support is mandated for any implementation. However, in some | ||||
environments, this approach may become a burden if keys frequently | ||||
change over time. Alternatively, a standard key management protocol | ||||
for secure key distribution can be used. However, existing key | ||||
distribution protocols may not be appropriate in all environments | ||||
because of the complexity or operational burden they involve. Finally, | ||||
[RSVP-CRYPTO-1] specifies how Kerberos [KERBEROS] may be used to | ||||
generate the RSVP Authentication keys. Kerberos allows for the use of | ||||
trusted third party keying relationships between security principals | ||||
(RSVP sender and receivers) where the Kerberos key distribution | ||||
center (KDC) establishes an ephemeral session key to be shared | ||||
between RSVP sender and receivers. | ||||
The use of RSVP Authentication in parts of the network where there | ||||
may be one or more IP hops in between two RSVP neighbors raises an | ||||
additional challenge. This is because, with some RSVP messages such | ||||
as a Path message, an RSVP router does not know the RSVP next hop for | ||||
that message at the time of forwarding it. In fact, part of the role | ||||
of a Path message is precisely to discover the RSVP next hop (and to | ||||
dynamically re-discover it when it changes, say because of a routing | ||||
change). Hence, the RSVP router may not know which security | ||||
association to use when forwarding such a message. | ||||
In that situation, one approach is to share the same RSVP | ||||
Authentication shared key across all the RSVP routers of a part of | ||||
the network where there may be RSVP neighbors with IP hops in between. | ||||
For example, all the RSVP routers of an administrative domain could | ||||
share the same RSVP Authentication key, while different per-neighbor | ||||
keys could be used between any RSVP router pair straddling the | ||||
boundary between two administrative domains that have agreed to use | ||||
RSVP signaling. | ||||
When the same RSVP Authentication shared key is to be shared among | ||||
multiple RSVP neighbors, manual key distribution may be used. For | ||||
situations where RSVP is being used for multicast flows, it might | ||||
also be possible, in the future, to adapt a multicast key management | ||||
method (e.g. from IETF Multicast Security Working Group) for key | ||||
distribution with such multicast RSVP usage. For situations where | ||||
RSVP Extensions for Emergency Services January 2007 | ||||
RSVP is being used for unicast flows within a single administrative | ||||
domain, the Kerberos technique described in Section 7 of [RSVP- | ||||
CRYPTO-1] might be considered. For situations where RSVP is being | ||||
used for unicast flows across domain boundaries, it is not currently | ||||
clear how one might provide automated key management. Specification | ||||
of a specific automated key management technique is outside the scope | ||||
of this document. Operators should consider these key management | ||||
issues when contemplating deployment of this specification. | ||||
4.2. Use of INTEGRITY object within the POLICY_DATA object | ||||
The INTEGRITY object within the POLICY_DATA object can be used to | ||||
guarantee integrity between non-neighboring RSVP PEPs. | ||||
Details for computation of the content of the INTEGRITY object can be | ||||
found in Appendix B of [RSVP-POLICY]. This states that the Policy | ||||
Decision Point (PDP), at its discretion, and based on destination | ||||
PEP/PDP or other criteria, selects an Authentication Key and the hash | ||||
algorithm to be used. Keys to be used between PDPs can be distributed | ||||
manually or via standard key management protocol for secure key | ||||
distribution. | ||||
Note that where non-RSVP hops may exist in between RSVP hops, as well | ||||
as where RSVP capable Policy Ignorant Nodes (PINs) may exist in | ||||
between PEPs, it may be difficult for the PDP to determine what is | ||||
the destination PDP for a POLICY_DATA object contained in some RSVP | ||||
messages (such as a Path message). This is because in those cases the | ||||
next PEP is not known at the time of forwarding the message. This | ||||
issue is similar to the one discussed in section 4.1, except it now | ||||
applies to PDP neighbors instead of RSVP neighbors. Hence similar | ||||
approaches could be used, such as the use of a key shared across | ||||
multiple PDPs. We observe that this issue may not exist in some | ||||
deployment scenarios where a single (or low number of) PDP is used to | ||||
control all the PEPs of a region (such as an administrative domain). | ||||
In such scenarios, it may be easy for a PDP to determine what is the | ||||
next hop PDP, even when the next hop PEP is not known, simply by | ||||
determining what is the next region that will be traversed (say based | ||||
on the destination address). | ||||
5. IANA Considerations | 5. IANA Considerations | |||
As specified in [POLICY-RSVP], Standard RSVP Policy Elements (P-type | As specified in [RSVP-POLICY], Standard RSVP Policy Elements (P-type | |||
values) are to be assigned by IANA as per "IETF Consensus" following | values) are to be assigned by IANA as per "IETF Consensus" following | |||
the policies outlined in [IANA-CONSIDERATIONS]. | the policies outlined in [IANA-CONSIDERATIONS]. | |||
IANA needs to allocate two P-Types from the Standard RSVP Policy | IANA needs to allocate two P-Types from the Standard RSVP Policy | |||
Element range: | Element range: | |||
- one P-Type to the Admission Priority Policy Element | - one P-Type to the Admission Priority Policy Element | |||
RSVP Extensions for Emergency Services January 2007 | ||||
- one P-Type to the Application-Level Resource Priority | - one P-Type to the Application-Level Resource Priority | |||
Policy Element | Policy Element | |||
RSVP Extensions for Emergency Services October 2006 | ||||
6. Acknowledgments | 6. Acknowledgments | |||
We would like to thank An Nguyen for his encouragement to address | We would like to thank An Nguyen for his encouragement to address | |||
this topic and ongoing comments. Also, this document borrows heavily | this topic and ongoing comments. Also, this document borrows heavily | |||
from some of the work of S. Herzog on Preemption Priority Policy | from some of the work of S. Herzog on Preemption Priority Policy | |||
Element [RSVP-PREEMP]. Dave Oran and Janet Gunn provided useful input | Element [RSVP-PREEMP]. Dave Oran and Janet Gunn provided useful input | |||
into this document. | into this document. | |||
7. Normative References | 7. Normative References | |||
[DSTE-MAM] Le Faucheur & Lai, "Maximum Allocation Bandwidth | ||||
Constraints Model for Diffserv-aware MPLS Traffic Engineering", RFC | ||||
4125, June 2005. | ||||
[DSTE-RDM] Le Faucheur et al, Russian Dolls Bandwidth Constraints | ||||
Model for Diffserv-aware MPLS Traffic Engineering, RFC 4127, June | ||||
2005 | ||||
[EMERG-RQTS] Carlberg, K. and R. Atkinson, "General Requirements for | [EMERG-RQTS] Carlberg, K. and R. Atkinson, "General Requirements for | |||
Emergency Telecommunication Service (ETS)", RFC 3689, February 2004. | Emergency Telecommunication Service (ETS)", RFC 3689, February 2004. | |||
[EMERG-TEL] Carlberg, K. and R. Atkinson, "IP Telephony Requirements | [EMERG-TEL] Carlberg, K. and R. Atkinson, "IP Telephony Requirements | |||
for Emergency Telecommunication Service (ETS)", RFC 3690, February | for Emergency Telecommunication Service (ETS)", RFC 3690, February | |||
2004. | 2004. | |||
[FW-POLICY] Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework | ||||
for Policy-based Admission Control", RFC 2753, January 2000. | ||||
[IANA-CONSIDERATIONS] Alverstrand et al., "Guidelines for Writing an | ||||
IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. | ||||
[KEYWORDS] "Key words for use in RFCs to Indicate Requirement Levels", | ||||
Bradner, RFC2119, BCP14 | ||||
[KERBEROS] Neuman et al., "The Kerberos Network Authentication | ||||
Service (V5)", RFC 4120, July 2005. | ||||
[RSVP] Braden, R., ed., et al., "Resource ReSerVation Protocol | [RSVP] Braden, R., ed., et al., "Resource ReSerVation Protocol | |||
(RSVP)- Functional Specification", RFC 2205, September 1997. | (RSVP)- Functional Specification", RFC 2205, September 1997. | |||
[FW-POLICY] Yavatkar, R., Pendarakis, D., and R. Guerin, "A | [RSVP-CRYPTO-1] Baker, F., Lindell, B., and M. Talwar, "RSVP | |||
Framework for Policy-based Admission Control", RFC 2753, January 2000. | Cryptographic Authentication", RFC 2747, January 2000. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
[RSVP-CRYPTO-2] Braden, R. and L. Zhang, "RSVP Cryptographic | ||||
Authentication -- Updated Message Type Value", RFC 3097, April 2001. | ||||
[RSVP-POLICY] Herzog, S., "RSVP Extensions for Policy Control", RFC | [RSVP-POLICY] Herzog, S., "RSVP Extensions for Policy Control", RFC | |||
2750, January 2000. | 2750, January 2000. | |||
[RSVP-PREEMP] Herzog, S., "Signaled Preemption Priority Policy | [RSVP-PREEMP] Herzog, S., "Signaled Preemption Priority Policy | |||
Element", RFC 3181, October 2001. | Element", RFC 3181, October 2001. | |||
[DSTE-MAM] Le Faucheur & Lai, "Maximum Allocation Bandwidth | [SIP] Rosenberg et al., "SIP: Session Initiation Protocol", RFC3261, | |||
Constraints Model for Diffserv-aware MPLS Traffic Engineering", RFC | [SIP-PRIORITY] H. Schulzrinne & J. Polk. "Communications Resource | |||
4125, June 2005. | Priority for the Session Initiation Protocol (SIP)", RFC4412, | |||
February 2006. | ||||
[DSTE-RDM] Le Faucheur et al, Russian Dolls Bandwidth Constraints | ||||
Model for Diffserv-aware MPLS Traffic Engineering, RFC 4127, June | ||||
2005 | ||||
[SIP-PRIORITY] H. Schulzrinne & J. Polk. Communications Resource | ||||
Priority for the Session Initiation Protocol (SIP), RFC4412, February | ||||
2006. | ||||
8. Informative References | 8. Informative References | |||
[EMERG-IMP] F. Baker & J. Polk, "Implementing an Emergency | [EMERG-IMP] F. Baker & J. Polk, "Implementing an Emergency | |||
Telecommunications Service for Real Time Services in the Internet | Telecommunications Service for Real Time Services in the Internet | |||
Protocol Suite", RFC 4542, May 2006. | Protocol Suite", RFC 4542, May 2006. | |||
RSVP Extensions for Emergency Services October 2006 | ||||
[ITU.I.225] ITU, "Multi-Level Precedence and Preemption Service, ITU, | [ITU.I.225] ITU, "Multi-Level Precedence and Preemption Service, ITU, | |||
Recommendation, I.255.3, July, 1990. | Recommendation, I.255.3, July, 1990. | |||
[RSVP-ID] Yadav, S., Yavatkar, R., Pabbati, R., Ford, P., Moore, T., | [RSVP-ID] Yadav, S., Yavatkar, R., Pabbati, R., Ford, P., Moore, T., | |||
Herzog, S., and R. Hess, "Identity Representation for RSVP", RFC 3182, | Herzog, S., and R. Hess, "Identity Representation for RSVP", RFC 3182, | |||
October 2001. | October 2001. | |||
[RSVP-CRYPTO-1] Baker, F., Lindell, B., and M. Talwar, "RSVP | ||||
Cryptographic Authentication", RFC 2747, January 2000. | ||||
[RSVP-CRYPTO-2] Braden, R. and L. Zhang, "RSVP Cryptographic | ||||
Authentication -- Updated Message Type Value", RFC 3097, April 2001. | ||||
[SIP-RESOURCE] Camarillo, G., Marshall, W., and J. Rosenberg, | [SIP-RESOURCE] Camarillo, G., Marshall, W., and J. Rosenberg, | |||
"Integration of Resource Management and Session Initiation Protocol | "Integration of Resource Management and Session Initiation Protocol | |||
(SIP)", RFC 3312, October 2002. | (SIP)", RFC 3312, October 2002. | |||
Appendix A: Examples of Bandwidth Allocation Model for Admission | Appendix A: Examples of Bandwidth Allocation Model for Admission | |||
Priority | Priority | |||
Sections A.1 and A.2 respectively illustrate how the Maximum | Sections A.1 and A.2 respectively illustrate how the Maximum | |||
Allocation Model [DSTE-MAM] and the Russian Dolls Model (RDM) [DSTE- | Allocation Model [DSTE-MAM] and the Russian Dolls Model (RDM) [DSTE- | |||
RDM] can be used for support of admission priority. Section A.3 | RDM] can be used for support of admission priority. Section A.3 | |||
illustrates how a simple "Priority Bypass Model" can also be used for | illustrates how a simple "Priority Bypass Model" can also be used for | |||
support of admission priority. | support of admission priority. | |||
For simplicity, operations with only a single "priority" level | For simplicity, operations with only a single "priority" level | |||
(beyond non-priority) are illustrated here; However, the reader will | (beyond non-priority) are illustrated here; However, the reader will | |||
appreciate that operations with multiple priority levels can easily | appreciate that operations with multiple priority levels can easily | |||
be supported with these models. | be supported with these models. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
In all the charts below: | In all the charts below: | |||
x represents a non-priority session | x represents a non-priority session | |||
o represents a priority session | o represents a priority session | |||
A.1 Admission Priority with Maximum Allocation Model (MAM) | A.1 Admission Priority with Maximum Allocation Model (MAM) | |||
This section illustrates operations of admission priority when a | This section illustrates operations of admission priority when a | |||
Maximum Allocation Model (MAM) is used for bandwidth allocation | Maximum Allocation Model (MAM) is used for bandwidth allocation | |||
across non-priority traffic and priority traffic. A property of the | across non-priority traffic and priority traffic. A property of the | |||
Maximum Allocation Model is that priority traffic can not use more | Maximum Allocation Model is that priority traffic can not use more | |||
than the bandwidth made available to priority traffic (even if the | than the bandwidth made available to priority traffic (even if the | |||
non-priority traffic is not using all of the bandwidth available for | non-priority traffic is not using all of the bandwidth available for | |||
it). | it). | |||
----------------------- | ----------------------- | |||
RSVP Extensions for Emergency Services October 2006 | ||||
^ ^ ^ | | ^ | ^ ^ ^ | | ^ | |||
. . . | | . | . . . | | . | |||
Total . . . | | . Bandwidth | Total . . . | | . Bandwidth | |||
(1)(2)(3) | | . Available | (1)(2)(3) | | . Available | |||
Engi- . . . | | . for non-priority use | Engi- . . . | | . for non-priority use | |||
neered .or.or. | | . | neered .or.or. | | . | |||
. . . | | . | . . . | | . | |||
Capacity. . . | | . | Capacity. . . | | . | |||
v . . | | v | v . . | | v | |||
. . |--------------| --- | . . |--------------| --- | |||
skipping to change at page 15, line 39 | skipping to change at page 18, line 4 | |||
be accepted even if the bandwidth reserved for priority traffic is | be accepted even if the bandwidth reserved for priority traffic is | |||
not currently fully utilized. | not currently fully utilized. | |||
With the Maximum Allocation Model, in the case where the priority | With the Maximum Allocation Model, in the case where the priority | |||
load reaches the maximum bandwidth reserved for priority calls, no | load reaches the maximum bandwidth reserved for priority calls, no | |||
additional priority sessions can be accepted. | additional priority sessions can be accepted. | |||
As illustrated in Chart 1, an operator may map the MAM model onto the | As illustrated in Chart 1, an operator may map the MAM model onto the | |||
Engineered Capacity limits according to different policies. At one | Engineered Capacity limits according to different policies. At one | |||
extreme, where the proportion of priority traffic is reliably known | extreme, where the proportion of priority traffic is reliably known | |||
RSVP Extensions for Emergency Services January 2007 | ||||
to be fairly small at all times and where there may be some safety | to be fairly small at all times and where there may be some safety | |||
margin factored in the engineered capacity limits, the operator may | margin factored in the engineered capacity limits, the operator may | |||
decide to configure the bandwidth available for non-priority use to | decide to configure the bandwidth available for non-priority use to | |||
the full engineered capacity limits; effectively allowing the | the full engineered capacity limits; effectively allowing the | |||
priority traffic to ride within the safety margin of this engineered | priority traffic to ride within the safety margin of this engineered | |||
capacity. This policy can be seen as an economically attractive | capacity. This policy can be seen as an economically attractive | |||
approach as all of the engineered capacity is made available to non- | approach as all of the engineered capacity is made available to non- | |||
priority calls. This policy illustrated as (1) in Chart 1. As an | priority calls. This policy illustrated as (1) in Chart 1. As an | |||
example, if the engineered capacity limit on a given link is X, the | example, if the engineered capacity limit on a given link is X, the | |||
operator may configure the bandwidth available to non-priority | operator may configure the bandwidth available to non-priority | |||
traffic to X, and the bandwidth available to priority traffic to 5% | traffic to X, and the bandwidth available to priority traffic to 5% | |||
of X. | of X. | |||
At the other extreme, where the proportion of priority traffic may be | At the other extreme, where the proportion of priority traffic may be | |||
significant at times and the engineered capacity limits are very | significant at times and the engineered capacity limits are very | |||
tight, the operator may decide to configure the bandwidth available | tight, the operator may decide to configure the bandwidth available | |||
to non-priority traffic and the bandwidth available to priority | to non-priority traffic and the bandwidth available to priority | |||
RSVP Extensions for Emergency Services October 2006 | ||||
traffic such that their sum is equal to the engineered capacity | traffic such that their sum is equal to the engineered capacity | |||
limits. This guarantees that the total load across non-priority and | limits. This guarantees that the total load across non-priority and | |||
priority traffic is always below the engineered capacity and, in turn, | priority traffic is always below the engineered capacity and, in turn, | |||
guarantees there will never be any QoS degradation. However, this | guarantees there will never be any QoS degradation. However, this | |||
policy is less attractive economically as it prevents non-priority | policy is less attractive economically as it prevents non-priority | |||
calls from using the full engineered capacity, even when there is no | calls from using the full engineered capacity, even when there is no | |||
or little priority load, which is the majority of time. This policy | or little priority load, which is the majority of time. This policy | |||
illustrated as (3) in Chart 1. As an example, if the engineered | illustrated as (3) in Chart 1. As an example, if the engineered | |||
capacity limit on a given link is X, the operator may configure the | capacity limit on a given link is X, the operator may configure the | |||
bandwidth available to non-priority traffic to 95% of X, and the | bandwidth available to non-priority traffic to 95% of X, and the | |||
skipping to change at page 16, line 39 | skipping to change at page 19, line 4 | |||
. . . | | . Available | . . . | | . Available | |||
Engi- . . . | | . for non-priority use | Engi- . . . | | . for non-priority use | |||
neered .or.or. |xxxxxxxxxxxxxx| . | neered .or.or. |xxxxxxxxxxxxxx| . | |||
. . . |xxxxxxxxxxxxxx| . | . . . |xxxxxxxxxxxxxx| . | |||
Capacity. . . |xxxxxxxxxxxxxx| . | Capacity. . . |xxxxxxxxxxxxxx| . | |||
v . . |xxxxxxxxxxxxxx| v | v . . |xxxxxxxxxxxxxx| v | |||
. . |--------------| --- | . . |--------------| --- | |||
v . | | ^ | v . | | ^ | |||
. | | . Bandwidth available for | . | | . Bandwidth available for | |||
v | | v priority use | v | | v priority use | |||
RSVP Extensions for Emergency Services January 2007 | ||||
------------------------- | ------------------------- | |||
Chart 2. Partial load of non-priority calls | Chart 2. Partial load of non-priority calls | |||
Chart 3 shows the same amount of non-priority load being used at this | Chart 3 shows the same amount of non-priority load being used at this | |||
link, and a small amount of priority bandwidth being used. | link, and a small amount of priority bandwidth being used. | |||
----------------------- | ----------------------- | |||
^ ^ ^ | | ^ | ^ ^ ^ | | ^ | |||
. . . | | . | . . . | | . | |||
Total . . . | | . Bandwidth | Total . . . | | . Bandwidth | |||
. . . | | . Available | . . . | | . Available | |||
Engi- . . . | | . for non-priority use | Engi- . . . | | . for non-priority use | |||
neered .or.or. |xxxxxxxxxxxxxx| . | neered .or.or. |xxxxxxxxxxxxxx| . | |||
. . . |xxxxxxxxxxxxxx| . | . . . |xxxxxxxxxxxxxx| . | |||
Capacity. . . |xxxxxxxxxxxxxx| . | Capacity. . . |xxxxxxxxxxxxxx| . | |||
v . . |xxxxxxxxxxxxxx| v | v . . |xxxxxxxxxxxxxx| v | |||
RSVP Extensions for Emergency Services October 2006 | ||||
. . |--------------| --- | . . |--------------| --- | |||
v . | | ^ | v . | | ^ | |||
. | | . Bandwidth available for | . | | . Bandwidth available for | |||
v |oooooooooooooo| v priority use | v |oooooooooooooo| v priority use | |||
------------------------- | ------------------------- | |||
Chart 3. Partial load of non-priority calls | Chart 3. Partial load of non-priority calls | |||
& partial load of priority calls | & partial load of priority calls | |||
Chart 4 shows the case where non-priority load equates or exceeds the | Chart 4 shows the case where non-priority load equates or exceeds the | |||
skipping to change at page 17, line 39 | skipping to change at page 20, line 5 | |||
Capacity. . . |xxxxxxxxxxxxxx| . | Capacity. . . |xxxxxxxxxxxxxx| . | |||
v . . |xxxxxxxxxxxxxx| v | v . . |xxxxxxxxxxxxxx| v | |||
. . |--------------| --- | . . |--------------| --- | |||
v . | | ^ | v . | | ^ | |||
. | | . Bandwidth available for | . | | . Bandwidth available for | |||
v |oooooooooooooo| v priority use | v |oooooooooooooo| v priority use | |||
------------------------- | ------------------------- | |||
Chart 4. Full non-priority load | Chart 4. Full non-priority load | |||
& partial load of priority calls | & partial load of priority calls | |||
RSVP Extensions for Emergency Services January 2007 | ||||
Chart 5 shows the case where the priority traffic equates or exceeds | Chart 5 shows the case where the priority traffic equates or exceeds | |||
the bandwidth reserved for such priority traffic. | the bandwidth reserved for such priority traffic. | |||
In that case additional priority sessions could not be accepted. Note | In that case additional priority sessions could not be accepted. Note | |||
that this does not mean that such calls are dropped altogether: they | that this does not mean that such calls are dropped altogether: they | |||
may be handled by mechanisms, which are beyond the scope of this | may be handled by mechanisms, which are beyond the scope of this | |||
particular document (such as establishment through preemption of | particular document (such as establishment through preemption of | |||
existing non-priority sessions, or such as queuing of new priority | existing non-priority sessions, or such as queuing of new priority | |||
session requests until capacity becomes available again for priority | session requests until capacity becomes available again for priority | |||
traffic). | traffic). | |||
----------------------- | ----------------------- | |||
^ ^ ^ |xxxxxxxxxxxxxx| ^ | ^ ^ ^ |xxxxxxxxxxxxxx| ^ | |||
. . . |xxxxxxxxxxxxxx| . | . . . |xxxxxxxxxxxxxx| . | |||
Total . . . |xxxxxxxxxxxxxx| . Bandwidth | Total . . . |xxxxxxxxxxxxxx| . Bandwidth | |||
RSVP Extensions for Emergency Services October 2006 | ||||
. . . |xxxxxxxxxxxxxx| . Available | . . . |xxxxxxxxxxxxxx| . Available | |||
Engi- . . . |xxxxxxxxxxxxxx| . for non-priority use | Engi- . . . |xxxxxxxxxxxxxx| . for non-priority use | |||
neered .or.or. |xxxxxxxxxxxxxx| . | neered .or.or. |xxxxxxxxxxxxxx| . | |||
. . . |xxxxxxxxxxxxxx| . | . . . |xxxxxxxxxxxxxx| . | |||
Capacity. . . | | . | Capacity. . . | | . | |||
v . . | | v | v . . | | v | |||
. . |--------------| --- | . . |--------------| --- | |||
v . |oooooooooooooo| ^ | v . |oooooooooooooo| ^ | |||
. |oooooooooooooo| . Bandwidth available for | . |oooooooooooooo| . Bandwidth available for | |||
v |oooooooooooooo| v priority use | v |oooooooooooooo| v priority use | |||
skipping to change at page 18, line 38 | skipping to change at page 21, line 5 | |||
As with the MAM model, an operator may map the RDM model onto the | As with the MAM model, an operator may map the RDM model onto the | |||
Engineered Capacity limits according to different policies. The | Engineered Capacity limits according to different policies. The | |||
operator may decide to configure the bandwidth available for non- | operator may decide to configure the bandwidth available for non- | |||
priority use to the full engineered capacity limits; As an example, | priority use to the full engineered capacity limits; As an example, | |||
if the engineered capacity limit on a given link is X, the operator | if the engineered capacity limit on a given link is X, the operator | |||
may configure the bandwidth available to non-priority traffic to X, | may configure the bandwidth available to non-priority traffic to X, | |||
and the bandwidth available to non-priority and priority traffic to | and the bandwidth available to non-priority and priority traffic to | |||
105% of X. | 105% of X. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
Alternatively, the operator may decide to configure the bandwidth | Alternatively, the operator may decide to configure the bandwidth | |||
available to non-priority and priority traffic to the engineered | available to non-priority and priority traffic to the engineered | |||
capacity limits; As an example, if the engineered capacity limit on a | capacity limits; As an example, if the engineered capacity limit on a | |||
given link is X, the operator may configure the bandwidth available | given link is X, the operator may configure the bandwidth available | |||
to non-priority traffic to 95% of X, and the bandwidth available to | to non-priority traffic to 95% of X, and the bandwidth available to | |||
non-priority and priority traffic to X. | non-priority and priority traffic to X. | |||
Finally, the operator may decide to strike a balance in between. The | Finally, the operator may decide to strike a balance in between. The | |||
considerations presented for these policies in the previous section | considerations presented for these policies in the previous section | |||
in the MAM context are equally applicable to RDM. | in the MAM context are equally applicable to RDM. | |||
Chart 6 shows the case where only some of the bandwidth available to | Chart 6 shows the case where only some of the bandwidth available to | |||
non-priority traffic is being used and a small amount of priority | non-priority traffic is being used and a small amount of priority | |||
traffic is in place. In that situation both new non-priority sessions | traffic is in place. In that situation both new non-priority sessions | |||
and new priority sessions would be accepted. | and new priority sessions would be accepted. | |||
RSVP Extensions for Emergency Services October 2006 | ||||
-------------------------------------- | -------------------------------------- | |||
|xxxxxxxxxxxxxx| . ^ | |xxxxxxxxxxxxxx| . ^ | |||
|xxxxxxxxxxxxxx| . Bandwidth . | |xxxxxxxxxxxxxx| . Bandwidth . | |||
|xxxxxxxxxxxxxx| . Available for . | |xxxxxxxxxxxxxx| . Available for . | |||
|xxxxxxxxxxxxxx| . non-priority . | |xxxxxxxxxxxxxx| . non-priority . | |||
|xxxxxxxxxxxxxx| . use . | |xxxxxxxxxxxxxx| . use . | |||
|xxxxxxxxxxxxxx| . . Bandwidth | |xxxxxxxxxxxxxx| . . Bandwidth | |||
| | . . available for | | | . . available for | |||
| | v . non-priority | | | v . non-priority | |||
|--------------| --- . and priority | |--------------| --- . and priority | |||
skipping to change at page 19, line 38 | skipping to change at page 22, line 4 | |||
-------------------------------------- | -------------------------------------- | |||
|xxxxxxxxxxxxxx| . ^ | |xxxxxxxxxxxxxx| . ^ | |||
|xxxxxxxxxxxxxx| . Bandwidth . | |xxxxxxxxxxxxxx| . Bandwidth . | |||
|xxxxxxxxxxxxxx| . Available for . | |xxxxxxxxxxxxxx| . Available for . | |||
|xxxxxxxxxxxxxx| . non-priority . | |xxxxxxxxxxxxxx| . non-priority . | |||
|xxxxxxxxxxxxxx| . use . | |xxxxxxxxxxxxxx| . use . | |||
|xxxxxxxxxxxxxx| . . Bandwidth | |xxxxxxxxxxxxxx| . . Bandwidth | |||
|xxxxxxxxxxxxxx| . . available for | |xxxxxxxxxxxxxx| . . available for | |||
|xxxxxxxxxxxxxx| v . non-priority | |xxxxxxxxxxxxxx| v . non-priority | |||
RSVP Extensions for Emergency Services January 2007 | ||||
|--------------| --- . and priority | |--------------| --- . and priority | |||
| | . use | | | . use | |||
| | . | | | . | |||
|oooooooooooooo| v | |oooooooooooooo| v | |||
--------------------------------------- | --------------------------------------- | |||
Chart 7. Full non-priority load & Partial Aggregate load | Chart 7. Full non-priority load & Partial Aggregate load | |||
Chart 8 shows the case where only some of the bandwidth available to | Chart 8 shows the case where only some of the bandwidth available to | |||
non-priority traffic is being used and a heavy load of priority | non-priority traffic is being used and a heavy load of priority | |||
traffic is in place. In that situation both new non-priority sessions | traffic is in place. In that situation both new non-priority sessions | |||
and new priority sessions would be accepted. | and new priority sessions would be accepted. | |||
Note that, as illustrated in Chart 7, priority calls use some of the | Note that, as illustrated in Chart 7, priority calls use some of the | |||
bandwidth currently not used by non-priority traffic. | bandwidth currently not used by non-priority traffic. | |||
-------------------------------------- | -------------------------------------- | |||
RSVP Extensions for Emergency Services October 2006 | ||||
|xxxxxxxxxxxxxx| . ^ | |xxxxxxxxxxxxxx| . ^ | |||
|xxxxxxxxxxxxxx| . Bandwidth . | |xxxxxxxxxxxxxx| . Bandwidth . | |||
|xxxxxxxxxxxxxx| . Available for . | |xxxxxxxxxxxxxx| . Available for . | |||
|xxxxxxxxxxxxxx| . non-priority . | |xxxxxxxxxxxxxx| . non-priority . | |||
|xxxxxxxxxxxxxx| . use . | |xxxxxxxxxxxxxx| . use . | |||
| | . . Bandwidth | | | . . Bandwidth | |||
| | . . available for | | | . . available for | |||
|oooooooooooooo| v . non-priority | |oooooooooooooo| v . non-priority | |||
|--------------| --- . and priority | |--------------| --- . and priority | |||
|oooooooooooooo| . use | |oooooooooooooo| . use | |||
skipping to change at page 20, line 38 | skipping to change at page 23, line 4 | |||
may be handled by mechanisms, which are beyond the scope of this | may be handled by mechanisms, which are beyond the scope of this | |||
particular document (such as established through preemption of | particular document (such as established through preemption of | |||
existing non-priority sessions, or such as queuing of new priority | existing non-priority sessions, or such as queuing of new priority | |||
session requests until capacity becomes available again for priority | session requests until capacity becomes available again for priority | |||
traffic). | traffic). | |||
-------------------------------------- | -------------------------------------- | |||
|xxxxxxxxxxxxxx| . ^ | |xxxxxxxxxxxxxx| . ^ | |||
|xxxxxxxxxxxxxx| . Bandwidth . | |xxxxxxxxxxxxxx| . Bandwidth . | |||
|xxxxxxxxxxxxxx| . Available for . | |xxxxxxxxxxxxxx| . Available for . | |||
RSVP Extensions for Emergency Services January 2007 | ||||
|xxxxxxxxxxxxxx| . non-priority . | |xxxxxxxxxxxxxx| . non-priority . | |||
|xxxxxxxxxxxxxx| . use . | |xxxxxxxxxxxxxx| . use . | |||
|xxxxxxxxxxxxxx| . . Bandwidth | |xxxxxxxxxxxxxx| . . Bandwidth | |||
|xxxxxxxxxxxxxx| . . available for | |xxxxxxxxxxxxxx| . . available for | |||
|xxxxxxxxxxxxxx| v . non-priority | |xxxxxxxxxxxxxx| v . non-priority | |||
|--------------| --- . and priority | |--------------| --- . and priority | |||
|oooooooooooooo| . use | |oooooooooooooo| . use | |||
|oooooooooooooo| . | |oooooooooooooo| . | |||
|oooooooooooooo| v | |oooooooooooooo| v | |||
--------------------------------------- | --------------------------------------- | |||
Chart 9. Full non-priority load & Full Aggregate load | Chart 9. Full non-priority load & Full Aggregate load | |||
A.3 Admission Priority with Priority Bypass Model (PBM) | A.3 Admission Priority with Priority Bypass Model (PBM) | |||
RSVP Extensions for Emergency Services October 2006 | ||||
This section illustrates operations of admission priority when a | This section illustrates operations of admission priority when a | |||
simple Priority Bypass Model (PBM) is used for bandwidth allocation | simple Priority Bypass Model (PBM) is used for bandwidth allocation | |||
across non-priority traffic and priority traffic. With the Priority | across non-priority traffic and priority traffic. With the Priority | |||
Bypass Model, non-priority traffic is subject to resource based | Bypass Model, non-priority traffic is subject to resource based | |||
admission control while priority traffic simply bypasses the resource | admission control while priority traffic simply bypasses the resource | |||
based admission control. In other words: | based admission control. In other words: | |||
- when a non-priority call arrives, this call is subject to | - when a non-priority call arrives, this call is subject to | |||
bandwidth admission control and is accepted if the current total load | bandwidth admission control and is accepted if the current total load | |||
(aggregate over non-priority and priority traffic) is below the | (aggregate over non-priority and priority traffic) is below the | |||
engineered/allocated bandwidth. | engineered/allocated bandwidth. | |||
skipping to change at page 21, line 39 | skipping to change at page 24, line 4 | |||
used, those always still represent a fairly small proportion of | used, those always still represent a fairly small proportion of | |||
the overall load which can be absorbed within the safety margin | the overall load which can be absorbed within the safety margin | |||
of the engineered capacity limits. Thus, even if they are | of the engineered capacity limits. Thus, even if they are | |||
admitted beyond the engineered bandwidth threshold, they are | admitted beyond the engineered bandwidth threshold, they are | |||
unlikely to result in noticeable QoS degradation. | unlikely to result in noticeable QoS degradation. | |||
As with the MAM and RDM model, an operator may map the Priority | As with the MAM and RDM model, an operator may map the Priority | |||
Bypass model onto the Engineered Capacity limits according to | Bypass model onto the Engineered Capacity limits according to | |||
different policies. The operator may decide to configure the | different policies. The operator may decide to configure the | |||
bandwidth limit for admission of non-priority traffic to the full | bandwidth limit for admission of non-priority traffic to the full | |||
RSVP Extensions for Emergency Services January 2007 | ||||
engineered capacity limits; As an example, if the engineered capacity | engineered capacity limits; As an example, if the engineered capacity | |||
limit on a given link is X, the operator may configure the bandwidth | limit on a given link is X, the operator may configure the bandwidth | |||
limit for non-priority traffic to X. Alternatively, the operator may | limit for non-priority traffic to X. Alternatively, the operator may | |||
decide to configure the bandwidth limit for non-priority traffic to | decide to configure the bandwidth limit for non-priority traffic to | |||
below the engineered capacity limits (so that the sum of the non- | below the engineered capacity limits (so that the sum of the non- | |||
priority and priority traffic stays below the engineered capacity); | priority and priority traffic stays below the engineered capacity); | |||
As an example, if the engineered capacity limit on a given link is X, | As an example, if the engineered capacity limit on a given link is X, | |||
the operator may configure the bandwidth limit for non-priority | the operator may configure the bandwidth limit for non-priority | |||
traffic to 95% of X. Finally, the operator may decide to strike a | traffic to 95% of X. Finally, the operator may decide to strike a | |||
balance in between. The considerations presented for these policies | balance in between. The considerations presented for these policies | |||
in the previous sections in the MAM and RDM contexts are equally | in the previous sections in the MAM and RDM contexts are equally | |||
applicable to the Priority Bypass Model. | applicable to the Priority Bypass Model. | |||
Chart 10 shows illustrates the bandwidth allocation with the Priority | Chart 10 shows illustrates the bandwidth allocation with the Priority | |||
Bypass Model. | Bypass Model. | |||
----------------------- | ----------------------- | |||
RSVP Extensions for Emergency Services October 2006 | ||||
^ ^ | | ^ | ^ ^ | | ^ | |||
. . | | . | . . | | . | |||
Total . . | | . Bandwidth Limit | Total . . | | . Bandwidth Limit | |||
(1) (2) | | . (on non-priority + priority) | (1) (2) | | . (on non-priority + priority) | |||
Engi- . . | | . for admission | Engi- . . | | . for admission | |||
neered . or . | | . of non-priority traffic | neered . or . | | . of non-priority traffic | |||
. . | | . | . . | | . | |||
Capacity. . | | . | Capacity. . | | . | |||
v . | | v | v . | | v | |||
. |--------------| --- | . |--------------| --- | |||
skipping to change at page 22, line 39 | skipping to change at page 25, line 4 | |||
. . |xxxxxxxxxxxxxx| . | . . |xxxxxxxxxxxxxx| . | |||
Total . . |xxxxxxxxxxxxxx| . Bandwidth Limit | Total . . |xxxxxxxxxxxxxx| . Bandwidth Limit | |||
(1) (2) |xxxxxxxxxxxxxx| . (on non-priority + priority) | (1) (2) |xxxxxxxxxxxxxx| . (on non-priority + priority) | |||
Engi- . . | | . for admission | Engi- . . | | . for admission | |||
neered . or . | | . of non-priority traffic | neered . or . | | . of non-priority traffic | |||
. . | | . | . . | | . | |||
Capacity. . | | . | Capacity. . | | . | |||
v . | | v | v . | | v | |||
. |--------------| --- | . |--------------| --- | |||
. | | | . | | | |||
RSVP Extensions for Emergency Services January 2007 | ||||
v | | | v | | | |||
| | | | | | |||
Chart 11. Partial load of non-priority calls | Chart 11. Partial load of non-priority calls | |||
Chart 12 shows the same amount of non-priority load being used at | Chart 12 shows the same amount of non-priority load being used at | |||
this link, and a small amount of priority bandwidth being used. In | this link, and a small amount of priority bandwidth being used. In | |||
this situation, both new non-priority and new priority calls would be | this situation, both new non-priority and new priority calls would be | |||
accepted. | accepted. | |||
----------------------- | ----------------------- | |||
^ ^ |xxxxxxxxxxxxxx| ^ | ^ ^ |xxxxxxxxxxxxxx| ^ | |||
. . |xxxxxxxxxxxxxx| . | . . |xxxxxxxxxxxxxx| . | |||
Total . . |xxxxxxxxxxxxxx| . Bandwidth Limit | Total . . |xxxxxxxxxxxxxx| . Bandwidth Limit | |||
(1) (2) |xxxxxxxxxxxxxx| . (on non-priority + priority) | (1) (2) |xxxxxxxxxxxxxx| . (on non-priority + priority) | |||
Engi- . . |oooooooooooooo| . for admission | Engi- . . |oooooooooooooo| . for admission | |||
RSVP Extensions for Emergency Services October 2006 | ||||
neered . or . | | . of non-priority traffic | neered . or . | | . of non-priority traffic | |||
. . | | . | . . | | . | |||
Capacity. . | | . | Capacity. . | | . | |||
v . | | v | v . | | v | |||
. |--------------| --- | . |--------------| --- | |||
. | | | . | | | |||
v | | | v | | | |||
| | | | | | |||
Chart 12. Partial load of non-priority calls | Chart 12. Partial load of non-priority calls | |||
skipping to change at page 23, line 39 | skipping to change at page 26, line 5 | |||
Engi- . . |oooooooooooooo| . for admission | Engi- . . |oooooooooooooo| . for admission | |||
neered . or . |xxxooxxxooxxxo| . of non-priority traffic | neered . or . |xxxooxxxooxxxo| . of non-priority traffic | |||
. . |xxoxxxxxxoxxxx| . | . . |xxoxxxxxxoxxxx| . | |||
Capacity. . |oxxxooooxxxxoo| . | Capacity. . |oxxxooooxxxxoo| . | |||
v . |xxoxxxooxxxxxx| v | v . |xxoxxxooxxxxxx| v | |||
. |--------------| --- | . |--------------| --- | |||
. |oooooooooooooo| | . |oooooooooooooo| | |||
v | | | v | | | |||
| | | | | | |||
RSVP Extensions for Emergency Services January 2007 | ||||
Chart 13. Full non-priority load | Chart 13. Full non-priority load | |||
Appendix B: Example Usages of RSVP Extensions | Appendix B: Example Usages of RSVP Extensions | |||
This section provides examples of how RSVP extensions defined in this | This section provides examples of how RSVP extensions defined in this | |||
document can be used (in conjunctions with other RSVP functionality | document can be used (in conjunctions with other RSVP functionality | |||
and SIP functionality) to enforce different hypothetical policies for | and SIP functionality) to enforce different hypothetical policies for | |||
handling Emergency sessions in a given administrative domain. This | handling Emergency sessions in a given administrative domain. This | |||
Appendix does not provide additional specification. It is only | Appendix does not provide additional specification. It is only | |||
included in this document for illustration purposes. The content of | included in this document for illustration purposes. The content of | |||
this appendix may be moved into a future applicability statement | this appendix may be moved into a future applicability statement | |||
document. | document. | |||
RSVP Extensions for Emergency Services October 2006 | ||||
We assume an environment where SIP is used for session control and | We assume an environment where SIP is used for session control and | |||
RSVP is used for resource reservation. | RSVP is used for resource reservation. | |||
In a mild abuse of language, we refer here to "Call Queueing" as the | In a mild abuse of language, we refer here to "Call Queueing" as the | |||
set of "session" layer capabilities that may be implemented by SIP | set of "session" layer capabilities that may be implemented by SIP | |||
user agents to influence their treatment of SIP requests. This may | user agents to influence their treatment of SIP requests. This may | |||
include the ability to "queue" call requests when those can not be | include the ability to "queue" call requests when those can not be | |||
immediately honored (in some cases with the notion of "bumping", or | immediately honored (in some cases with the notion of "bumping", or | |||
"displacement", of less important call request from that queue). It | "displacement", of less important call request from that queue). It | |||
may include additional mechanisms such as exemption from certain | may include additional mechanisms such as exemption from certain | |||
skipping to change at page 24, line 39 | skipping to change at page 27, line 4 | |||
* not using Admission-Priority Policy Element in RSVP | * not using Admission-Priority Policy Element in RSVP | |||
* not using Preemption Policy Element in RSVP | * not using Preemption Policy Element in RSVP | |||
If one wants to implement an emergency service based on Call | If one wants to implement an emergency service based on Call | |||
Queueing and on "prioritized access to network layer resources", one | Queueing and on "prioritized access to network layer resources", one | |||
can achieve this by signaling emergency calls: | can achieve this by signaling emergency calls: | |||
* using "Resource-Priority" Header in SIP | * using "Resource-Priority" Header in SIP | |||
* using Admission-Priority Policy Element in RSVP | * using Admission-Priority Policy Element in RSVP | |||
* not using Preemption Policy Element in RSVP | * not using Preemption Policy Element in RSVP | |||
Emergency calls will not result in preemption of any session. | Emergency calls will not result in preemption of any session. | |||
RSVP Extensions for Emergency Services January 2007 | ||||
Different bandwidth allocation models can be used to offer different | Different bandwidth allocation models can be used to offer different | |||
"prioritized access to network resources". Just as examples, this | "prioritized access to network resources". Just as examples, this | |||
includes strict setting aside of capacity for emergency sessions as | includes strict setting aside of capacity for emergency sessions as | |||
well as simple bypass of admission limits for emergency sessions. | well as simple bypass of admission limits for emergency sessions. | |||
If one wants to implement an emergency service based on Call Queueing, | If one wants to implement an emergency service based on Call Queueing, | |||
on "prioritized access to network layer resources", and ensures that | on "prioritized access to network layer resources", and ensures that | |||
(say) "Emergency-1" sessions can preempt "Emergency-2" sessions, but | (say) "Emergency-1" sessions can preempt "Emergency-2" sessions, but | |||
non-emergency sessions are not affected by preemption, one can do | non-emergency sessions are not affected by preemption, one can do | |||
that by signaling emergency calls: | that by signaling emergency calls: | |||
* using "Resource-Priority" Header in SIP | * using "Resource-Priority" Header in SIP | |||
* using Admission-Priority Policy Element in RSVP | * using Admission-Priority Policy Element in RSVP | |||
* using Preemption Policy Element in RSVP with: | * using Preemption Policy Element in RSVP with: | |||
o setup (Emergency-1) > defending (Emergency-2) | o setup (Emergency-1) > defending (Emergency-2) | |||
o setup (Emergency-2) <= defending (Emergency-1) | o setup (Emergency-2) <= defending (Emergency-1) | |||
o setup (Emergency-1) <= defending (Non-Emergency) | o setup (Emergency-1) <= defending (Non-Emergency) | |||
o setup (Emergency-2) <= defending (Non-Emergency) | o setup (Emergency-2) <= defending (Non-Emergency) | |||
RSVP Extensions for Emergency Services October 2006 | ||||
If one wants to implement an emergency service based on Call Queueing, | If one wants to implement an emergency service based on Call Queueing, | |||
on "prioritized access to network layer resources", and ensure that | on "prioritized access to network layer resources", and ensure that | |||
"emergency" sessions can preempt regular sessions, one could do that | "emergency" sessions can preempt regular sessions, one could do that | |||
by signaling emergency calls: | by signaling emergency calls: | |||
* using "Resource-Priority" Header in SIP | * using "Resource-Priority" Header in SIP | |||
* using Admission-Priority Policy Element in RSVP | * using Admission-Priority Policy Element in RSVP | |||
* using Preemption Policy Element in RSVP with: | * using Preemption Policy Element in RSVP with: | |||
o setup (Emergency) > defending (Non-Emergency) | o setup (Emergency) > defending (Non-Emergency) | |||
o setup (Non-Emergency) <= defending (Emergency) | o setup (Non-Emergency) <= defending (Emergency) | |||
skipping to change at page 25, line 35 | skipping to change at page 28, line 4 | |||
o setup (Emergency) > defending (Non-Emergency) | o setup (Emergency) > defending (Non-Emergency) | |||
o setup (Non-Emergency) <= defending (Emergency) | o setup (Non-Emergency) <= defending (Emergency) | |||
* activate RFC4495 RSVP Bandwidth Reduction mechanisms | * activate RFC4495 RSVP Bandwidth Reduction mechanisms | |||
Authors' Address | Authors' Address | |||
Francois Le Faucheur | Francois Le Faucheur | |||
Cisco Systems, Inc. | Cisco Systems, Inc. | |||
Village d'Entreprise Green Side - Batiment T3 | Village d'Entreprise Green Side - Batiment T3 | |||
400, Avenue de Roumanille | 400, Avenue de Roumanille | |||
RSVP Extensions for Emergency Services January 2007 | ||||
06410 Biot Sophia-Antipolis | 06410 Biot Sophia-Antipolis | |||
France | France | |||
Email: flefauch@cisco.com | Email: flefauch@cisco.com | |||
James Polk | James Polk | |||
Cisco Systems, Inc. | Cisco Systems, Inc. | |||
2200 East President George Bush Turnpike | 2200 East President George Bush Turnpike | |||
Richardson, Texas 75082 | Richardson, Texas 75082 | |||
USA | USA | |||
Email: jmpolk@cisco.com | Email: jmpolk@cisco.com | |||
Ken Carlberg | Ken Carlberg | |||
G11 | G11 | |||
123a Versailles Circle | 123a Versailles Circle | |||
Towson, MD. 21204 | Towson, MD. 21204 | |||
RSVP Extensions for Emergency Services October 2006 | ||||
USA | USA | |||
email: carlberg@g11.org.uk | email: carlberg@g11.org.uk | |||
IPR Statements | Intellectual Property | |||
The IETF takes no position regarding the validity or scope of any | The IETF takes no position regarding the validity or scope of any | |||
Intellectual Property Rights or other rights that might be claimed to | Intellectual Property Rights or other rights that might be claimed to | |||
pertain to the implementation or use of the technology described in | pertain to the implementation or use of the technology described in | |||
this document or the extent to which any license under such rights | this document or the extent to which any license under such rights | |||
might or might not be available; nor does it represent that it has | might or might not be available; nor does it represent that it has | |||
made any independent effort to identify any such rights. Information | made any independent effort to identify any such rights. Information | |||
on the procedures with respect to rights in RFC documents can be | on the procedures with respect to rights in RFC documents can be | |||
found in BCP 78 and BCP 79. | found in BCP 78 and BCP 79. | |||
Copies of IPR disclosures made to the IETF Secretariat and any | Copies of IPR disclosures made to the IETF Secretariat and any | |||
assurances of licenses to be made available, or the result of an | assurances of licenses to be made available, or the result of an | |||
attempt made to obtain a general license or permission for the use of | attempt made to obtain a general license or permission for the use of | |||
such proprietary rights by implementers or users of this | such proprietary rights by implementers or users of this | |||
specification can be obtained from the IETF on-line IPR repository at | specification can be obtained from the IETF on-line IPR repository at | |||
http://www.ietf.org/ipr. | http://www.ietf.org/ipr. | |||
The IETF invites any interested party to bring to its attention any | The IETF invites any interested party to bring to its attention any | |||
copyrights, patents or patent applications, or other proprietary | copyrights, patents or patent applications, or other proprietary | |||
rights that may cover technology that may be required to implement | rights that may cover technology that may be required to implement | |||
this standard. | this standard. Please address the information to the IETF at ietf- | |||
Please address the information to the IETF at ietf-ipr@ietf.org. | ipr@ietf.org. | |||
Disclaimer of Validity | Full Copyright Statement | |||
RSVP Extensions for Emergency Services January 2007 | ||||
Copyright (C) The Internet Society (2007). | ||||
This document is subject to the rights, licenses and restrictions | ||||
contained in BCP 78, and except as set forth therein, the authors | ||||
retain all their rights. | ||||
This document and the information contained herein are provided on an | This document and the information contained herein are provided on an | |||
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS | "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS | |||
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET | OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET | |||
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, | ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, | |||
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE | INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE | |||
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED | INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED | |||
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. | WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. | |||
Copyright Notice | ||||
Copyright (C) The Internet Society (2006). This document is subject | ||||
to the rights, licenses and restrictions contained in BCP 78, and | ||||
except as set forth therein, the authors retain all their rights. | ||||
End of changes. 72 change blocks. | ||||
127 lines changed or deleted | 252 lines changed or added | |||
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