draft-ietf-dmm-ondemand-mobility-10.txt   draft-ietf-dmm-ondemand-mobility-11.txt 
DMM Working Group A. Yegin DMM Working Group A. Yegin
Internet-Draft Actility Internet-Draft Actility
Intended status: Informational D. Moses Intended status: Informational D. Moses
Expires: August 2, 2017 Intel Expires: December 26, 2017 Intel
K. Kweon K. Kweon
J. Lee J. Lee
J. Park J. Park
Samsung Samsung
S. Jeon S. Jeon
Sungkyunkwan University Sungkyunkwan University
January 29, 2017 June 24, 2017
On Demand Mobility Management On Demand Mobility Management
draft-ietf-dmm-ondemand-mobility-10 draft-ietf-dmm-ondemand-mobility-11
Abstract Abstract
Applications differ with respect to whether they need IP session Applications differ with respect to whether they need IP session
continuity and/or IP address reachability. The network providing the continuity and/or IP address reachability. The network providing the
same type of service to any mobile host and any application running same type of service to any mobile host and any application running
on the host yields inefficiencies. This document describes a on the host yields inefficiencies. This document describes a
solution for taking the application needs into account in selectively solution for taking the application needs into account by selectively
providing IP session continuity and IP address reachability on a per- providing IP session continuity and IP address reachability on a per-
socket basis. socket basis.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 2, 2017. This Internet-Draft will expire on December 26, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 22 skipping to change at page 2, line 22
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4
3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Types of IP Addresses . . . . . . . . . . . . . . . . . . 4 3.1. Types of IP Addresses . . . . . . . . . . . . . . . . . . 4
3.2. Granularity of Selection . . . . . . . . . . . . . . . . 5 3.2. Granularity of Selection . . . . . . . . . . . . . . . . 5
3.3. On Demand Nature . . . . . . . . . . . . . . . . . . . . 5 3.3. On Demand Nature . . . . . . . . . . . . . . . . . . . . 6
3.4. Conveying the Selection . . . . . . . . . . . . . . . . . 6 3.4. Conveying the Desired Address Type . . . . . . . . . . . 7
4. Usage example . . . . . . . . . . . . . . . . . . . . . . . . 9 4. Usage example . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Backwards Compatibility Considerations . . . . . . . . . . . 10 5. Backwards Compatibility Considerations . . . . . . . . . . . 10
5.1. Applications . . . . . . . . . . . . . . . . . . . . . . 11 5.1. Applications . . . . . . . . . . . . . . . . . . . . . . 10
5.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 11 5.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 10
5.3. Network Infrastructure . . . . . . . . . . . . . . . . . 11 5.3. Network Infrastructure . . . . . . . . . . . . . . . . . 10
6. Summary of New Definitions . . . . . . . . . . . . . . . . . 11 6. Summary of New Definitions . . . . . . . . . . . . . . . . . 11
6.1. New APIs . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2. New Flags . . . . . . . . . . . . . . . . . . . . . . . . 11
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
11.1. Normative References . . . . . . . . . . . . . . . . . . 13 11.1. Normative References . . . . . . . . . . . . . . . . . . 12
11.2. Informative References . . . . . . . . . . . . . . . . . 13 11.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
In the context of Mobile IP [RFC5563][RFC6275][RFC5213][RFC5944], In the context of Mobile IP [RFC5563][RFC6275][RFC5213][RFC5944], the
following two attributes are defined for the IP service provided to following two attributes are defined for IP service provided to
the mobile hosts: mobile hosts:
IP session continuity: The ability to maintain an ongoing IP session IP session continuity: The ability to maintain an ongoing IP session
by keeping the same local end-point IP address throughout the session by keeping the same local end-point IP address throughout the session
despite the mobile host changing its point of attachment within the despite the mobile host changing its point of attachment within the
IP network topology. The IP address of the host may change between IP network topology. The IP address of the host may change between
two independent IP sessions, but that does not jeopardize the IP two independent IP sessions, but that does not jeopardize its IP
session continuity. IP session continuity is essential for mobile session continuity. IP session continuity is essential for mobile
hosts to maintain ongoing flows without any interruption. hosts to maintain ongoing flows without any interruption.
IP address reachability: The ability to maintain the same IP address IP address reachability: The ability to maintain the same IP address
for an extended period of time. The IP address stays the same across for an extended period of time. The IP address stays the same across
independent IP sessions, and even in the absence of any IP session. independent IP sessions, and even in the absence of any IP session.
The IP address may be published in a long-term registry (e.g., DNS), The IP address may be published in a long-term registry (e.g., DNS),
and it is made available for serving incoming (e.g., TCP) and is made available for serving incoming (e.g., TCP) connections.
connections. IP address reachability is essential for mobile hosts IP address reachability is essential for mobile hosts to use
to use specific/published IP addresses. specific/published IP addresses.
Mobile IP is designed to provide both IP session continuity and IP Mobile IP is designed to provide both IP session continuity and IP
address reachability to mobile hosts. Architectures utilizing these address reachability to mobile hosts. Architectures utilizing these
protocols (e.g., 3GPP, 3GPP2, WIMAX) ensure that any mobile host protocols (e.g., 3GPP, 3GPP2, WIMAX) ensure that any mobile host
attached to the compliant networks can enjoy these benefits. Any attached to the compliant networks can enjoy these benefits. Any
application running on these mobile hosts is subjected to the same application running on these mobile hosts is subjected to the same
treatment with respect to the IP session continuity and IP address treatment with respect to IP session continuity and IP address
reachability. reachability.
It should be noted that in reality not every application may need It should be noted that in reality not every application may need
those benefits. IP address reachability is required for applications these benefits. IP address reachability is required for applications
running as servers (e.g., a web server running on the mobile host). running as servers (e.g., a web server running on the mobile host).
But, a typical client application (e.g., web browser) does not But, a typical client application (e.g., web browser) does not
necessarily require IP address reachability. Similarly, IP session necessarily require IP address reachability. Similarly, IP session
continuity is not required for all types of applications either. continuity is not required for all types of applications either.
Applications performing brief communication (e.g., DNS client) can Applications performing brief communication (e.g., ping) can survive
survive without having IP session continuity support. without having IP session continuity support.
Achieving IP session continuity and IP address reachability by using Achieving IP session continuity and IP address reachability with
Mobile IP incurs some cost. Mobile IP protocol forces the mobile Mobile IP incurs some cost. Mobile IP protocol forces the mobile
host's IP traffic to traverse a centrally-located router (Home Agent, host's IP traffic to traverse a centrally-located router (Home Agent,
HA), which incurs additional transmission latency and use of HA), which incurs additional transmission latency and use of
additional network resources, adds to the network CAPEX and OPEX, and additional network resources, adds to the network CAPEX and OPEX, and
decreases the reliability of the network due to the introduction of a decreases the reliability of the network due to the introduction of a
single point of failure [RFC7333]. Therefore, IP session continuity single point of failure [RFC7333]. Therefore, IP session continuity
and IP address reachability should be be provided only when needed. and IP address reachability should be provided only when necessary.
Furthermore, when an application needs session continuity, it may be Furthermore, when an application needs session continuity, it may be
able to satisfy that need by using a solution above the IP layer, able to satisfy that need by using a solution above the IP layer,
such as MPTCP [RFC6824], SIP mobility [RFC3261], or an application- such as MPTCP [RFC6824], SIP mobility [RFC3261], or an application-
layer mobility solution. Those higher-layer solutions are not layer mobility solution. These higher-layer solutions are not
subject to the same issues that arise with the use of Mobile IP since subject to the same issues that arise with the use of Mobile IP since
they can utilize the most direct data path between the end-points. they can utilize the most direct data path between the end-points.
But, if Mobile IP is being applied to the mobile host, those higher- But, if Mobile IP is being applied to the mobile host, the higher-
layer protocols are rendered useless because their operation is layer protocols are rendered useless because their operation is
inhibited by the Mobile IP. Since Mobile IP ensures that the IP inhibited by Mobile IP. Since Mobile IP ensures that the IP address
address of the mobile host remains fixed (despite the location and of the mobile host remains fixed (despite the location and movement
movement of the mobile host), the higher-layer protocols never detect of the mobile host), the higher-layer protocols never detect the IP-
the IP-layer change and never engage in mobility management. layer change and never engage in mobility management.
This document proposes a solution for the applications running on the This document proposes a solution for applications running on mobile
mobile host to indicate whether they need IP session continuity or IP hosts to indicate whether they need IP session continuity or IP
address reachability. The network protocol stack on the mobile host, address reachability. The network protocol stack on the mobile host,
in conjunction with the network infrastructure, would provide the in conjunction with the network infrastructure, would provide the
required type of IP service. It is for the benefit of both the users required type of IP service. It is for the benefit of both the users
and the network operators not to engage an extra level of service and the network operators not to engage an extra level of service
unless it is absolutely necessary. So it is expected that unless it is absolutely necessary. It is expected that applications
applications and networks compliant with this specification would and networks compliant with this specification would utilize this
utilize this solution to use network resources more efficiently. solution to use network resources more efficiently.
2. Notational Conventions 2. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. Solution 3. Solution
3.1. Types of IP Addresses 3.1. Types of IP Addresses
Three types of IP addresses are defined with respect to the mobility Four types of IP addresses are defined with respect to mobility
management. management.
- Fixed IP Address - Fixed IP Address
A Fixed IP address is an address with a guarantee to be valid for a A Fixed IP address is an address with a guarantee to be valid for a
very long time, regardless of whether it is being used in any packet very long time, regardless of whether it is being used in any packet
to/from the mobile host, or whether or not the mobile host is to/from the mobile host, or whether or not the mobile host is
connected to the network, or whether it moves from one point-of- connected to the network, or whether it moves from one point-of-
attachment to another (with a different subnet or IP prefix) while it attachment to another (with a different IP prefix) while it is
is connected. connected.
Fixed IP addresses are required by applications that need both IP Fixed IP addresses are required by applications that need both IP
session continuity and IP address reachability. session continuity and IP address reachability.
- Session-lasting IP Address - Session-lasting IP Address
A session-lasting IP address is an address with a guarantee to be A session-lasting IP address is an address with a guarantee to be
valid throughout the IP session(s) for which it was requested. It is valid throughout the IP session(s) for which it was requested. It is
guaranteed to be valid even after the mobile host had moved from one guaranteed to be valid even after the mobile host had moved from one
point-of-attachment to another (with a different subnet or IP point-of-attachment to another (with a different IP prefix).
prefix).
Session-lasting IP addresses are required by applications that need Session-lasting IP addresses are required by applications that need
IP session continuity but do not need IP address reachability. IP session continuity but do not need IP address reachability.
- Non-persistent IP Address - Non-persistent IP Address
This type of IP address provides neither IP session continuity nor IP
address reachability. The IP address is obtained from the serving IP This type of IP address does not provide IP session continuity nor IP
gateway and it is not maintained across gateway changes. In other address reachability. The IP address is created from an IP prefix
words, the IP address may be released and replaced by a new IP that is obtained from the serving IP gateway and is not maintained
address when the IP gateway changes due to the movement of the mobile across gateway changes. In other words, the IP prefix may be
host. released and replaced by a new one when the IP gateway changes due to
the movement of the mobile host forcing the creation of a new source
IP address with the updated allocated IP prefix.
- Graceful Replacement IP Address
In some cases, the network cannot guarantee the validity of the
provided IP prefix throughout the duration of the IP session, but can
provide a limited graceful period of time in which both the original
IP prefix and a new one are valid. This enables the application some
flexibility in the transition from the existing source IP address to
the new one.
This gracefulness is still better than the non-persistence type of
address for applications that can handle a change in their source IP
address but require that extra flexibility.
Applications running as servers at a published IP address require a Applications running as servers at a published IP address require a
Fixed IP Address. Long-standing applications (e.g., an SSH session) Fixed IP Address. Long-standing applications (e.g., an SSH session)
may also require this type of address. Enterprise applications that may also require this type of address. Enterprise applications that
connect to an enterprise network via virtual LAN require a Fixed IP connect to an enterprise network via virtual LAN require a Fixed IP
Address. Address.
Applications with short-lived transient IP sessions can use Session- Applications with short-lived transient IP sessions can use Session-
lasting IP Addresses. For example: Web browsers. lasting IP Addresses. For example: Web browsers.
Applications with very short IP sessions, such as DNS clients and Applications with very short IP sessions, such as DNS clients and
instant messengers, can utilize Non-persistent IP Addresses. Even instant messengers, can utilize Non-persistent IP Addresses. Even
though they could very well use Fixed or Session-lasting IP though they could very well use Fixed or Session-lasting IP
Addresses, the transmission latency would be minimized when a Non- Addresses, the transmission latency would be minimized when a Non-
persistent IP Addresses are used. persistent IP Addresses are used.
The network creates the desired guarantee (Fixed, Session-lasting or Applications that can tolerate a short interruption in connectivity
Non-persistent) by either assigning the address prefix (as part of a can use the Graceful-replacement IP addresses. For example, a
stateless address generation process), or by assigning an IP address streaming client that has buffering capabilities.
(as part of a stateful IP address generation).
The exact mechanism of prefix or address assignment is outside the
scope of this specification.
3.2. Granularity of Selection 3.2. Granularity of Selection
The IP address type selection is made on a per-socket granularity. IP address type selection is made on a per-socket granularity.
Different parts of the same application may have different needs. Different parts of the same application may have different needs.
For example, control-plane of an application may require a Fixed IP For example, the control-plane of an application may require a Fixed
Address in order to stay reachable, whereas data-plane of the same IP Address in order to stay reachable, whereas the data-plane of the
application may be satisfied with a Session-lasting IP Address. same application may be satisfied with a Session-lasting IP Address.
3.3. On Demand Nature 3.3. On Demand Nature
At any point in time, a mobile host may have a combination of IP At any point in time, a mobile host may have a combination of IP
addresses configured. Zero or more Non-persistent, zero or more addresses configured. Zero or more Non-persistent, zero or more
Session-lasting, and zero or more Fixed IP addresses may be Session-lasting, zero or more Fixed and zero or more Graceful-
configured on the IP stack of the host. The combination may be as a Replacement IP addresses may be configured by the IP stack of the
result of the host policy, application demand, or a mix of the two. host. The combination may be as a result of the host policy,
application demand, or a mix of the two.
When an application requires a specific type of IP address and such When an application requires a specific type of IP address and such
address is not already configured on the host, the IP stack shall an address is not already configured on the host, the IP stack shall
attempt to configure one. For example, a host may not always have a attempt to configure one. For example, a host may not always have a
Session-lasting IP address available. When an application requests Session-lasting IP address available. When an application requests
one, the IP stack shall make an attempt to configure one by issuing a one, the IP stack shall make an attempt to configure one by issuing a
request to the network (see section Section 3.4 for more details). request to the network (see Section 3.4 below for more details). If
If the operation fails, the IP stack shall fail the associated socket the operation fails, the IP stack shall fail the associated socket
request. If successful, a Session-lasting IP Address gets configured request and return an error. If successful, a Session-lasting IP
on the mobile host. If another socket requests a Session-lasting IP Address gets configured on the mobile host. If another socket
address at a later time, the same IP address may be served to that requests a Session-lasting IP address at a later time, the same IP
socket as well. When the last socket using the same configured IP address may be served to that socket as well. When the last socket
address is closed, the IP address may be released or kept for future using the same configured IP address is closed, the IP address may be
applications that may be launched and require a Session-lasting IP released or kept for future applications that may be launched and
address. require a Session-lasting IP address.
In some cases it might be preferable for the mobile host to request a In some cases it might be preferable for the mobile host to request a
new Session-lasting IP address for a new opening of an IP session new Session-lasting IP address for a new opening of an IP session
(even though one was already assigned to the mobile host by the (even though one was already assigned to the mobile host by the
network and might be in use in a different, already active IP network and might be in use in a different, already active IP
session). It is outside the scope of this specification to define session). It is outside the scope of this specification to define
criteria for selecting to use available addresses or choose to criteria for choosing to use available addresses or choosing to
request new ones. It supports both alternatives (and any request new ones. It supports both alternatives (and any
combination). combination).
It is outside the scope of this specification to define how the host It is outside the scope of this specification to define how the host
requests a specific type of address (Fixed, Session-lasting or Non- requests a specific type of prefix and how the network indicates the
persistent) and how the network indicates the type of address in its type of prefix in its advertisement or in its reply to a request).
advertisement of IP prefixes or addresses (or in its reply to a
request).
The following are matters of policy, which may be dictated by the The following are matters of policy, which may be dictated by the
host itself, the network operator, or the system architecture host itself, the network operator, or the system architecture
standard: standard:
- The initial set of IP addresses configured on the host at boot - The initial set of IP addresses configured on the host at boot
time. time.
- Permission to grant various types of IP addresses to a requesting - Permission to grant various types of IP addresses to a requesting
application. application.
- Determination of a default address type when an application does - Determination of a default address type when an application does
not make any explicit indication, whether it already supports the not make any explicit indication, whether it already supports the
required API or it is just a legacy application. required API or it is just a legacy application.
3.4. Conveying the Selection 3.4. Conveying the Desired Address Type
The selection of the address type is conveyed from the applications
to the IP stack in order to influence the source address selection
algorithm [RFC6724].
The current source address selection algorithm operates on the
available set of IP addresses, when selecting an address. According
to the proposed solution, if the requested IP address type is not
available at the time of the request, the IP stack shall make an
attempt to configure one such IP address. The selected IP address
shall be compliant with the requested IP address type, whether it is
selected among available addresses or dynamically configured. In the
absence of a matching type (because it is not available and not
configurable on demand), the source address selection algorithm shall
return an empty set.
A Socket API-based interface for enabling applications to influence
the source address selection algorithm is described in [RFC5014].
That specification defines IPV6_ADDR_PREFERENCES option at the
IPPROTO_IPV6 level. That option can be used with setsockopt() and
getsockopt() calls to set and get address selection preferences.
Furthermore, that RFC also specifies two flags that relate to IP
mobility management: IPV6_PREFER_SRC_HOME and IPV6_PREFER_SRC_COA.
These flags are used for influencing the source address selection to
prefer either a Home Address or a Care-of Address.
Unfortunately, these flags do not satisfy the aforementioned needs
due to the following reasons:
- Current flags indicate a "preference" whereas there is a need for
indicating "requirement". Source address selection algorithm does
not have to produce an IP address compliant with the "preference" ,
but it has to produce an IP address compliant with the "requirement".
- Current flags influence the selection made among available IP
addresses. The new flags force the IP stack to configure a compliant
IP address if none is available at the time of the request.
- The Home vs. Care-of Address distinction is not sufficient to
capture the three different types of IP addresses described in
Section 2.1.
The following new flags are defined in this document and they shall
be used with Socket API in compliance with [RFC5014]:
IPV6_REQUIRE_FIXED_IP /* Require a Fixed IP address as source */
IPV6_REQUIRE_SESSION_LASTING_IP /* Require a Session-lasting IP [RFC5014] introduced the ability of applications to influence the
address as source */ source address selection with the IPV6_ADDR_PREFERENCE option at the
IPPROTO_IPV6 level. This option is used with setsockopt() and
getsockopt() calls to set/get address selection preferences.
IPV6_REQUIRE_NON_PERSISTENT_IP /* Require a Non-persistent IP address Extending this further by adding more flags does not work when a
as source */ request for an address of a certain type results in requiring the IP
Only one of these flags may be set on the same socket. If an stack to wait for the network to provide the desired source IP prefix
application attempts to set more than one flag, the most recent and hence causing the setsockopt() call to block until the prefix is
setting will be the one in effect. allocated (or an error indication from the network is received).
When any of these new flags is used, the IPV6_PREFER_SRC_HOME and Alternatively a new Socket API is defined - getsc() which allows
IPV6_PREFER_SRC_COA flags, if used, shall be ignored. applications to express their desired type of session continuity
service. The new getsc() API will return an IPv6 address that is
associated with the desired session continuity service and with
status information indicating whether or not the desired service was
provided.
These new flags are used with setsockopt()/getsockopt(), An application that wishes to secure a desired service will call
getaddrinfo(), and inet6_is_srcaddr() functions [RFC5014]. Similar getsc() with the service type definition and a place to contain the
to the setsockopt()/getsockopt() calls, the getaddrinfo() call shall provided IP address, and call bind() to associate that IP address
also trigger configuration of the required IP address type, if one is with the Socket (See code example in Section 4 below).
not already available. When the new flags are used with
getaddrinfo() and the triggered configuration fails, the
getaddrinfo() call shall ignore that failure (i.e., not return an
error code to indicate that failure). Only the setsockopt() shall
return an error when configuration of the requested IP address type
fails.
When the IP stack is required to use a source IP address of a When the IP stack is required to use a source IP address of a
specified type, it can perform one of the following: It can use an specified type, it can use an existing address, or request a new IP
existing address (if it has one), or it can create a new one from an prefix (of the same type) from the network and create a new one. If
existing prefix of the desired type. If the host does not already the host does not already have an IPv6 prefix of that specific type,
have an IPv6 prefix of the specific type, it can request one from the it must request one from the network.
network.
Using an existing address from an existing prefix is faster but might Using an existing address from an existing prefix is faster but might
yield a less optimal route (if a hand-off event occurred since its yield a less optimal route (if a hand-off event occurred after its
configuration), on the other hand, acquiring a new IP prefix from the configuration). On the other hand, acquiring a new IP prefix from
network may take some time (due to signaling exchange with the the network may be slower due to signaling exchange with the network.
network) and may fail due to network policies.
An additional new flag - ON_NET flag - enables the application to
direct the IP stack whether to use a preconfigured source IP address
(if exists) or to request a new IPv6 prefix from the current serving
network and configure a new IP address:
IPV6_REQUIRE_SRC_ON_NET /* Set IP stack address allocation behavior
*/
If set, the IP stack will request a new IPv6 prefix of the desired
type from the current serving network and configure a new source IP
address. If reset, the IP stack will use a preconfigured one if
exists. If there is no preconfigured IP address of the desired type,
the IP stack will request a IPv6 prefix from the current serving
network (regardless of whether this flag is set or not).
The ON_NET flag must be used together with one of the 3 flags defined
above. If ON_NET flag is used without any of these flags, it must be
ignored. If the ON_NET flag is not used, the IP stack is free to
either use an existing IP address (if preconfigured) or access the
network to configure a new one (the decision is left to
implementation).
The following new error codes are also defined in the document and
will be used in the Socket API in compliance with [RFC5014].
EAI_REQUIREDIPNOTSUPPORTED /* The network does not support the Applications can control the stack's operation by setting a new flag
ability to request that specific IP address type */ - ON_NET flag - which directs the IP stack whether to use a
preconfigured source IP address (if exists) or to request a new IPv6
prefix from the current serving network and configure a new IP
address.
EAI_REQUIREDIPFAILED /* The network could not assign that specific IP This new flag is added to the set of flags in the
address type */ IPV6_ADDR_PREFERENCES option at the IPPROTO_IPV6 level. It is used
in setsockopt() to set the desired behavior.
4. Usage example 4. Usage example
The following example shows the code for creating a Stream socket The following example shows the code for creating a Stream socket
(TCP) with a Session-Lasting source IP address: (TCP) with a Session-Lasting source IP address:
#include <sys/socket.h> #include <sys/socket.h>
#include <netinnet/in.h> #include <netinnet/in.h>
// Socket information
int s ; // Socket id int s ; // Socket id
sockaddr_in6 serverAddress ; // server info for connect()
uint32_t flags = IPV6_REQUIRE_SESSION_LASTING_IP ; // Source information (for secsc() and bind())
sockaddr_in6 sourceInfo // my address and port for bind()
in6_addr sourceAddress // will contain the provisioned source
// IP address
uint8_t sc_type = IPV6_REQUIRE_SESSION_LASTING_IP ;
// For requesting a Session-Lasting // For requesting a Session-Lasting
// source IP address // source IP address
// Destination information (for connect())
sockaddr_in6 serverInfo ; // server info for connect()
// Create an IPv6 TCP socket // Create an IPv6 TCP socket
s = socket(AF_INET6, SOCK_STREAM, 0) ; s = socket(AF_INET6, SOCK_STREAM, 0) ;
if (s!=0) { if (s!=0) {
// Handle socket creation error // Handle socket creation error
// ... // ...
} // if socket creation failed } // if socket creation failed
else { else {
// Socket creation is successful
// Socket creation is successful // The application cannot connect yet, since it wants to use a
// The application cannot connect yet, since it wants to use a // Session-Lasting source IP address It needs to request the
// Session-Lasting source IP address It needs to request the // Session-Lasting source IP before connecting
// Session-Lasting source IP before connecting if (setsc(s, &sourceAddress, &sc_type)) == 0){
if (setsockopt(s,
IPPROTO_IPV6,
IPV6_ADDR_PREFERENCE,
(void *) flags,
sizeof(flags)) == 0){
// setting session continuity to Session Lasting is successful // setting session continuity to Session Lasting is successful
// The application can connect to the server // sourceAddress now contains the Session-Lasting source IP
// address
// Set the desired server's port# and IP address // Bind to that source IP address
serverAddress.sin6_port = serverPort ; sourceInfo.sin6_family = AF_INET6 ;
serverAddress.sin6_addr = serverIpAddress ; sourceInfo.sin6_port = 0 // let the stack choose the port
sourceInfo.sin6_address = sourceAddress ;
// Use the source address that was
// generated by the setsc() call
if (bind(s, &sourceInfo, sizeof(sourceInfo))==0){
// Set the desired server's information for connect()
serverInfo.sin6_family = AF_INET6 ;
serverInfo.sin6_port = SERVER_PORT_NUM ;
serverAddress.sin6_addr = SERVER_IPV6_ADDRESS ;
// Connect to the server // Connect to the server
if (connect(s, &serverAddress, sizeof(serverAddress))==0) { if (connect(s, &serverInfo, sizeof(serverInfo))==0) {
// connect successful (3-way handshake has been completed // connect successful (3-way handshake has been completed
// with Session-Lasting source address. // with Session-Lasting source address.
// Continue application functionality // Continue application functionality
// ... // ...
} // if connect() is successful } // if connect() is successful
else {
// connect failed
// ...
// Application code that handles connect failure and closes
// the socket
// ...
} // if connect() failed
} // if bind() successful
else { else {
// connect failed // bind() failed
// ... // ...
// Application code that handles connect failure and closes // Application code that handles bind failure and closes
// the socket // the socket
// ... // ...
} // if connect() failed } // if bind() failed
} // if setsc() was successful and of a Session-Lasting source address was provided
} // if the request of a Session-Lasting source address was successful else {
else {
// application code that does not use Session-lasting IP address // application code that does not use Session-lasting IP address
// The application may either connect without the desired // The application may either connect without the desired
// Session-lasting service, or close the socket // Session-lasting service, or close the socket
//... //...
} // if the socket was successfully created but a Session-Lasting source } // if setsc() failed
// address was not provided
} // if socket was created successfully } // if socket was created successfully
// The rest of the application's code // The rest of the application's code
// .. // ...
5. Backwards Compatibility Considerations 5. Backwards Compatibility Considerations
Backwards compatibility support is required by the following 3 types Backwards compatibility support is required by the following 3 types
of entities: of entities:
- The Applications on the mobile host - The Applications on the mobile host
- The IP stack in the mobile host - The IP stack in the mobile host
- The network infrastructure - The network infrastructure
5.1. Applications 5.1. Applications
Legacy applications that do not support the new flags will use the Legacy applications that do not support the OnDemand functionality
legacy API to the IP stack and will not enjoy On-Demand Mobility will use the legacy API and will not be able to take advantage of the
feature. On-Demand Mobility feature.
Applications using the new flags must be aware that they may be Applications using the new OnDemand functionality must be aware that
executed in environments that do not support the On-Demand Mobility they may be executed in legacy environments that do not support it.
feature. Such environments may include legacy IP stack in the mobile Such environments may include a legacy IP stack on the mobile host,
host, legacy network infrastructure, or both. In either case, the legacy network infrastructure, or both. In either case, the API will
API will return an error code and the invoking applications must return an error code and the invoking applications may just give up
respond with using legacy calls without the On-Demand Mobility and use legacy calls.
feature.
5.2. IP Stack in the Mobile Host 5.2. IP Stack in the Mobile Host
New IP stacks must continue to support all legacy operations. If an New IP stacks must continue to support all legacy operations. If an
application does not use On-Demand Mobility feature, the IP stack application does not use On-Demand functionality, the IP stack must
must respond in a legacy manner. respond in a legacy manner.
If the network infrastructure supports On-Demand Mobility feature, If the network infrastructure supports On-Demand functionality, the
the IP stack should follow the application request: If the IP stack should follow the application request: If the application
application requests a specific address type, the stack should requests a specific address type, the stack should forward this
forward this request to the network. If the application does not request to the network. If the application does not request an
request an address type, the IP stack must not request an address address type, the IP stack must not request an address type and leave
type and leave it to the network's default behavior to choose the it to the network's default behavior to choose the type of the
type of the allocated IP prefix. If an IP prefix was already allocated IP prefix. If an IP prefix was already allocated to the
allocated to the host, the IP stack uses it and may not request a new host, the IP stack uses it and may not request a new one from the
one from the network. network.
5.3. Network Infrastructure 5.3. Network Infrastructure
The network infrastructure may or may not support the On-Demand The network infrastructure may or may not support the On-Demand
Mobility feature. How the IP stack on the host and the network functionality. How the IP stack on the host and the network
infrastructure behave in case of a compatibility issue is outside the infrastructure behave in case of a compatibility issue is outside the
scope of this API specification. scope of this API specification.
6. Summary of New Definitions 6. Summary of New Definitions
The following list summarizes the new constants definitions discussed 6.1. New APIs
in this memo:
<netdb.h> IPV6_REQUIRE_FIXED_IP setsc() enables applications to request a specific type of source IP
<netdb.h> IPV6_REQUIRE_SESSION_LASTING_IP address in terms of session continuity. Its definition is:
<netdb.h> IPV6_REQUIRE_NON_PERSISTENT_IP
<netdb.h> IPV6_REQUIRE_SRC_ON_NET
<netdb.h> EAI_REQUIREDIPNOTSUPPORTED
<netdb.h> EAI_REQUIREDIPFAILED
<netinet/in.h> IPV6_REQUIRE_FIXED_IP int setsc (int sockfd, in6_addr *sourceAddress, sc_type addressType) ;
<netinet/in.h> IPV6_REQUIRE_SESSION_LASTING_IP
<netinet/in.h> IPV6_REQUIRE_NON_PERSISTENT_IP Where:
<netinet/in.h> IPV6_REQUIRE_SRC_ON_NET - sockfd - is the socket descriptor of the socket with which a
<netinet/in.h> EAI_REQUIREDIPNOTSUPPORTED specific address type is associated
<netinet/in.h> EAI_REQUIREDIPFAILED - sourceAddress - is a pointer to an area allocated for setsc() to place
the generated source IP address of the desired session
continuity type
- addressType - Is the desired type of session continuity service.
It is a 3-bit field containing one of the following
values:
0 - Reserved
1 - FIXED_IPV6_ADDRESS
2 - SESSION_LASTING_IPV6_ADDRESS
3 - NON_PERSISTENT_IPV6_ADDRESS
4 - GRACEFUL_REPLACEMENT_IPV6_ADDRESS
5-7 - Reserved
setsc() returns the status of the operation:
- 0 - Address was successfully generated
- EAI_REQUIREDIPNOTSUPPORTED - the required service type is not supported
- EAI_REQUIREDIPFAILED - the network could not fulfill the desired request
6.2. New Flags
The following flag is added to the list of flags in the
IPV6_ADDR_PREFERENCE option at the IPPROTO6 level:
IPV6_REQUIRE_SRC_ON_NET - set IP stack address allocation behavior
If set, the IP stack will request a new IPv6 prefix of the desired
type from the current serving network and configure a new source IP
address. If reset, the IP stack will use a preconfigured one if it
exists. If there is no preconfigured IP address of the desired type,
a new prefix will be requested and used for creating the IP address.
7. Security Considerations 7. Security Considerations
The setting of certain IP address type on a given socket may be The setting of certain IP address type on a given socket may be
restricted to privileged applications. For example, a Fixed IP restricted to privileged applications. For example, a Fixed IP
Address may be provided as a premium service and only certain Address may be provided as a premium service and only certain
applications may be allowed to use them. Setting and enforcement of applications may be allowed to use them. Setting and enforcement of
such privileges are outside the scope of this document. such privileges are outside the scope of this document.
8. IANA Considerations 8. IANA Considerations
skipping to change at page 13, line 7 skipping to change at page 12, line 37
Younghan Kim Younghan Kim
Soongsil University, Korea Soongsil University, Korea
Email: younghak@ssu.ac.kr Email: younghak@ssu.ac.kr
John Kaippallimalil John Kaippallimalil
Huawei, USA Huawei, USA
Email: john.kaippallimalil@huawei.com Email: john.kaippallimalil@huawei.com
10. Acknowledgements 10. Acknowledgements
We would like to thank Alexandru Petrescu, Jouni Korhonen, Sri We would like to thank Wu-chi Feng, Alexandru Petrescu, Jouni
Gundavelli, Dave Dolson and Lorenzo Colitti for their valuable Korhonen, Sri Gundavelli, Dave Dolson and Lorenzo Colitti for their
comments and suggestions on this work. valuable comments and suggestions on this work.
11. References 11. References
11.1. Normative References 11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 13, line 35 skipping to change at page 13, line 20
[RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown, [RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown,
"Default Address Selection for Internet Protocol Version 6 "Default Address Selection for Internet Protocol Version 6
(IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012, (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012,
<http://www.rfc-editor.org/info/rfc6724>. <http://www.rfc-editor.org/info/rfc6724>.
11.2. Informative References 11.2. Informative References
[I-D.sijeon-dmm-use-cases-api-source] [I-D.sijeon-dmm-use-cases-api-source]
Jeon, S., Figueiredo, S., Kim, Y., and J. Kaippallimalil, Jeon, S., Figueiredo, S., Kim, Y., and J. Kaippallimalil,
"Use Cases and API Extension for Source IP Address "Use Cases and API Extension for Source IP Address
Selection", draft-sijeon-dmm-use-cases-api-source-05 (work Selection", draft-sijeon-dmm-use-cases-api-source-06 (work
in progress), October 2016. in progress), March 2017.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E. A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261, Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002, DOI 10.17487/RFC3261, June 2002,
<http://www.rfc-editor.org/info/rfc3261>. <http://www.rfc-editor.org/info/rfc3261>.
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V., [RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008, RFC 5213, DOI 10.17487/RFC5213, August 2008,
 End of changes. 63 change blocks. 
260 lines changed or deleted 241 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/