--- 1/draft-ietf-dmm-srv6-mobile-uplane-04.txt 2019-07-08 06:13:04.428583495 -0700 +++ 2/draft-ietf-dmm-srv6-mobile-uplane-05.txt 2019-07-08 06:13:04.484584906 -0700 @@ -1,62 +1,62 @@ DMM Working Group S. Matsushima Internet-Draft SoftBank Intended status: Standards Track C. Filsfils -Expires: September 12, 2019 M. Kohno +Expires: January 9, 2020 M. Kohno P. Camarillo Cisco Systems, Inc. D. Voyer Bell Canada C. Perkins Futurewei - March 11, 2019 + July 8, 2019 Segment Routing IPv6 for Mobile User Plane - draft-ietf-dmm-srv6-mobile-uplane-04 + draft-ietf-dmm-srv6-mobile-uplane-05 Abstract This document shows the applicability of SRv6 (Segment Routing IPv6) to the user-plane of mobile networks. The network programming nature of SRv6 accomplish mobile user-plane functions in a simple manner. The statelessness of SRv6 and its ability to control both service layer path and underlying transport can be beneficial to the mobile - user-plane, providing flexibility and SLA control for various - applications. This document describes the SRv6 mobile user plane - behavior and defines the SID functions for that. + user-plane, providing flexibility, end-to-end network slicing and SLA + control for various applications. This document describes the SRv6 + mobile user plane behavior and defines the SID functions for that. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- - Drafts is at https://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 and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on September 12, 2019. + This Internet-Draft will expire on January 9, 2020. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents - (https://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 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 @@ -78,34 +78,33 @@ 5.3. Enhanced mode with unchanged gNB GTP behavior . . . . . . 11 5.3.1. Interworking with IPv6 GTP . . . . . . . . . . . . . 12 5.3.2. Interworking with IPv4 GTP . . . . . . . . . . . . . 15 5.3.3. Extensions to the interworking mechanisms . . . . . . 17 6. SRv6 SID Mobility Functions . . . . . . . . . . . . . . . . . 18 6.1. Args.Mob.Session . . . . . . . . . . . . . . . . . . . . 18 6.2. End.MAP . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.3. End.M.GTP6.D . . . . . . . . . . . . . . . . . . . . . . 19 6.4. End.M.GTP6.E . . . . . . . . . . . . . . . . . . . . . . 19 6.5. End.M.GTP4.E . . . . . . . . . . . . . . . . . . . . . . 20 - 6.6. T.M.Tmap . . . . . . . . . . . . . . . . . . . . . . . . 20 - 6.7. End.Limit: Rate Limiting function . . . . . . . . . . . . 21 + 6.6. T.M.GTP4.D . . . . . . . . . . . . . . . . . . . . . . . 21 + 6.7. End.Limit: Rate Limiting function . . . . . . . . . . . . 22 7. SRv6 supported 3GPP PDU session types . . . . . . . . . . . . 22 - 8. Network Slicing Considerations . . . . . . . . . . . . . . . 22 - 9. Control Plane Considerations . . . . . . . . . . . . . . . . 22 - 10. Security Considerations . . . . . . . . . . . . . . . . . . . 23 - 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 - 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 - 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 + 8. Network Slicing Considerations . . . . . . . . . . . . . . . 23 + 9. Control Plane Considerations . . . . . . . . . . . . . . . . 23 + 10. Security Considerations . . . . . . . . . . . . . . . . . . . 24 + 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 + 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24 + 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 24 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 14.1. Normative References . . . . . . . . . . . . . . . . . . 24 14.2. Informative References . . . . . . . . . . . . . . . . . 25 - Appendix A. Implementations . . . . . . . . . . . . . . . . . . 26 - Appendix B. Changes from revision 02 to revision 03 . . . . . . 26 + Appendix A. Implementations . . . . . . . . . . . . . . . . . . 27 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 1. Introduction In mobile networks, mobility management systems provide connectivity while mobile nodes move. While the control-plane of the system signals movements of a mobile node, the user-plane establishes a tunnel between the mobile node and its anchor node over IP-based backhaul and core networks. @@ -175,21 +174,21 @@ detailed behavior, the (S3, S2, S1; SL) notation is more convenient. o SRH[SL] represents the SID pointed by the SL field in the first SRH. In our example, SRH[2] represents S1, SRH[1] represents S2 and SRH[0] represents S3. o SRH[SL] can be different from the DA of the IPv6 header. 2.3. Predefined SRv6 Functions The following functions are defined in - [I-D.filsfils-spring-srv6-network-programming]. + [I-D.ietf-spring-srv6-network-programming]. o End.DT4 means to decapsulate and forward using a specific IPv4 table lookup. o End.DT6 means to decapsulate and forward using a specific IPv6 table lookup. o End.DX4 means to decapsulate the packet and forward through a particular outgoing interface -or set of OIFs- configured with the SID. o End.DX6 means to decapsulate and forward through a particular @@ -224,24 +223,24 @@ In the meantime, applications have shifted to use IPv6, and network operators have started adopting IPv6 as their IP transport. SRv6, the IPv6 dataplane instantiation of Segment Routing [RFC8402], integrates both the application data-path and the underlying transport layer into a single protocol, allowing operators to optimize the network in a simplified manner and removing forwarding state from the network. It is also suitable for virtualized environments, VNF/CNF to VNF/CNF networking. SRv6 specifies network-programming (see - [I-D.filsfils-spring-srv6-network-programming]). Applied to - mobility, SRv6 can provide the user-plane functions needed for - mobility management. SRv6 takes advantage of underlying transport - awareness and flexibility to improve mobility user-plane functions. + [I-D.ietf-spring-srv6-network-programming]). Applied to mobility, + SRv6 can provide the user-plane functions needed for mobility + management. SRv6 takes advantage of underlying transport awareness + and flexibility to improve mobility user-plane functions. The use-cases for SRv6 mobility are discussed in [I-D.camarilloelmalky-springdmm-srv6-mob-usecases]. 4. A 3GPP Reference Architecture This section presents a reference architecture and possible deployment scenarios. Figure 1 shows a reference diagram from the 5G packet core @@ -308,35 +307,35 @@ We introduce two mechanisms for interworking with legacy access networks (N3 interface is unmodified). In these document we introduce them applied to the Enhanced mode, although they could be used in combination with the Traditional mode as well. One of these mechanisms is designed to interwork with legacy gNBs using GTP/IPv4. The second method is designed to interwork with legacy gNBs using GTP/IPv6. This document uses SRv6 functions defined in - [I-D.filsfils-spring-srv6-network-programming] as well as new SRv6 + [I-D.ietf-spring-srv6-network-programming] as well as new SRv6 functions designed for the mobile user plane. The new SRv6 functions are detailed in Section 6. 5.1. Traditional mode In the traditional mode, the existing mobile UPFs remain unchanged except for the use of SRv6 as the data plane instead of GTP-U. There is no impact to the rest of mobile system. - In existing 3GPP mobile networks, an UE session is mapped 1-for-1 + In existing 3GPP mobile networks, an UE PDU Session is mapped 1-for-1 with a specific GTP tunnel (TEID). This 1-for-1 mapping is mirrored here to replace GTP encapsulation with the SRv6 encapsulation, while not changing anything else. There will be a unique SRv6 SID - associated with each UE session. + associated with each UE PDU Session. The traditional mode minimizes the changes required to the mobile system; it is a good starting point for forming a common basis. Our example topology is shown in Figure 2. In traditional mode the gNB and the UPFs are SR-aware. In the descriptions of the uplink and downlink packet flow, A is an IPv6 address of the UE, and Z is an IPv6 address reachable within the Data Network DN. A new SRv6 function End.MAP, defined in Section 6.2, is used. @@ -377,43 +376,42 @@ 5.1.2. Packet flow - Downlink The downlink packet flow is as follows: UPF2_in : (Z,A) UPF2_out: (U2::, U1::1) (Z,A) -> T.Encaps.Red UPF1_out: (U2::, gNB::1) (Z,A) -> End.MAP gNB_out : (Z,A) -> End.DX4 or End.DX6 When the packet arrives at the UPF2, the UPF2 maps that flow into a - UE session. This UE session is associated with the segment endpoint - . UPF2 performs a T.Encaps.Red operation, encapsulating the - packet into a new IPv6 header with no SRH since there is only one - SID. + UE PDU Session. This UE PDU Session is associated with the segment + endpoint . UPF2 performs a T.Encaps.Red operation, + encapsulating the packet into a new IPv6 header with no SRH since + there is only one SID. Upon packet arrival on UPF1, the SID U1::1 is a local End.MAP function. This function maps the SID to the next anchoring point and replaces U1::1 by gNB::1, that belongs to the next hop. Upon packet arrival on gNB, the SID gNB::1 corresponds to an End.DX4 or End.DX6 function. The gNB decapsulates the packet, removing the IPv6 header and all its extensions headers, and forwards the traffic toward the UE. 5.1.3. IPv6 user-traffic For IPv6 user-traffic it is RECOMMENDED to perform encapsulation. However based on local policy, a service provider MAY choose to do - SRH insertion [I-D.voyer-6man-extension-header-insertion] . The main - benefit is a lower overhead (40B less). In such case, the functions - used are T.Insert.Red at gNB, End.MAP at UPF1 and End.T at UPF2 on - Uplink, T.Insert.Red at UPF2, End.MAP at UPF1 and End.X at gNB on - Downlink. + SRH insertion. The main benefit is a lower overhead(40B less). In + such case, the functions used are T.Insert.Red at gNB, End.MAP at + UPF1 and End.T at UPF2 on Uplink, T.Insert.Red at UPF2, End.MAP at + UPF1 and End.X at gNB on Downlink. 5.2. Enhanced Mode Enhanced mode improves scalability, traffic steering and service programming [I-D.xuclad-spring-sr-service-programming], thanks to the use of multiple SIDs, instead of a single SID as done in the Traditional mode. The main difference is that the SR policy MAY include SIDs for traffic engineering and service programming in addition to the UPFs @@ -480,23 +478,23 @@ The downlink packet flow is as follows: UPF2_in : (Z,A) -> UPF2 maps the flow w/ SID list UPF2_out: (U2::1, C1)(gNB, S1; SL=2)(Z,A) -> T.Encaps.Red C1_out : (U2::1, S1)(gNB, S1; SL=1)(Z,A) S1_out : (U2::1, gNB)(Z,A) -> PSP gNB_out : (Z,A) -> End.DX4 or End.DX6 When the packet arrives at the UPF2, the UPF2 maps that particular - flow into a UE session. This UE session is associated with the - policy . The UPF2 performs a T.Encaps.Red operation, - encapsulating the packet into a new IPv6 header with its + flow into a UE PDU Session. This UE PDU Session is associated with + the policy . The UPF2 performs a T.Encaps.Red + operation, encapsulating the packet into a new IPv6 header with its corresponding SRH. The nodes C1 and S1 perform their related Endpoint processing. Once the packet arrives at the gNB, the IPv6 DA corresponds to an End.DX4 or End.DX6 (depending on the underlying traffic). The gNB decapsulates the packet, removing the IPv6 header and all its extensions headers and forwards the traffic toward the UE. 5.2.3. IPv6 user-traffic @@ -583,21 +581,21 @@ S1_out : (SRGW, C1)(U2::1, C1; SL=1)(A,Z) C1_out : (SRGW, U2::1)(A,Z) -> PSP UPF2_out: (A,Z) -> End.DT4 or End.DT6 The UE sends a packet destined to Z toward the gNB on a specific bearer for that session. The gNB, which is unmodified, encapsulates the packet into IPv6, UDP and GTP headers. The IPv6 DA B, and the GTP TEID T are the ones received in the N2 interface. The IPv6 address that was signalled over the N2 interface for that UE - session, B, is now the IPv6 DA. B is an SRv6 Binding SID at the + PDU Session, B, is now the IPv6 DA. B is an SRv6 Binding SID at the SRGW. Hence the packet is routed to the SRGW. When the packet arrives at the SRGW, the SRGW identifies B as an End.M.GTP6.D Binding SID (see Section 6.3). Hence, the SRGW removes the IPv6, UDP and GTP headers, and pushes an IPv6 header with its own SRH containing the SIDs bound to the SR policy associated with this BindingSID. There is one instance of the End.M.GTP6.D SID per PDU type. S1 and C1 perform their related Endpoint functionality and forward @@ -642,23 +640,23 @@ and forward it on the bearer. This gNB behavior is not modified from current and previous generations. 5.3.1.3. Scalability For the downlink traffic, the SRGW is stateless. All the state is in the SRH inserted by the UPF2. The UPF2 must have the UE states since it is the UE's session anchor point. For the uplink traffic, the state at the SRGW does not necessarily - need to be unique per UE session; the state state can be shared among - UEs. This enables much more scalable SRGW deployments compared to a - solution holding millions of states, one or more per UE. + need to be unique per UE PDU Session; the state state can be shared + among UEs. This enables much more scalable SRGW deployments compared + to a solution holding millions of states, one or more per UE. 5.3.1.4. IPv6 user-traffic For IPv6 user-traffic it is RECOMMENDED to perform encapsulation. However based on local policy, a service provider MAY choose to do SRH insertion. The main benefit is lower overhead. 5.3.2. Interworking with IPv4 GTP In this interworking mode the gNB uses GTP over IPv4 in the N3 @@ -693,33 +691,33 @@ SR Gateway Figure 6: Enhanced mode with unchanged gNB IPv4/GTP behavior 5.3.2.1. Packet flow - Uplink The uplink packet flow is as follows: gNB_out : (gNB, B)(GTP: TEID T)(A,Z) -> Interface N3 unchanged IPv4/GTP - SRGW_out: (SRGW, S1)(U2::1, C1; SL=2)(A,Z) -> T.M.Tmap function + SRGW_out: (SRGW, S1)(U2::1, C1; SL=2)(A,Z) -> T.M.GTP4.D function S1_out : (SRGW, C1)(U2::1, C1; SL=1)(A,Z) C1_out : (SRGW, U2::1) (A,Z) -> PSP UPF2_out: (A,Z) -> End.DT4 or End.DT6 The UE sends a packet destined to Z toward the gNB on a specific bearer for that session. The gNB, which is unmodified, encapsulates the packet into a new IPv4, UDP and GTP headers. The IPv4 DA, B, and the GTP TEID are the ones received at the N2 interface. When the packet arrives at the SRGW for UPF1, the SRGW has an Uplink Classifier rule for incoming traffic from the gNB, that steers the - traffic into an SR policy by using the function T.M.TMap. The SRGW + traffic into an SR policy by using the function T.M.GTP4.D. The SRGW removes the IPv4, UDP and GTP headers and pushes an IPv6 header with its own SRH containing the SIDs related to the SR policy associated with this traffic. The SRGW forwards according to the new IPv6 DA. S1 and C1 perform their related Endpoint functionality and forward the packet. When the packet arrives at UPF2, the active segment is (U2::1) which is bound to End.DT4/6 which performs the decapsulation (removing the outer IPv6 header with all its extension headers) and forwards toward @@ -827,134 +825,170 @@ 6.2. End.MAP The "Endpoint function with SID mapping" function (End.MAP for short) is used in several scenarios. Particularly in mobility, End.MAP is used in the UPFs for the PDU Session anchor functionality. When a SR node N receives a packet destined to S and S is a local End.MAP SID, N does the following: - 1. look up the IPv6 DA in the mapping table - 2. update the IPv6 DA with the new mapped SID ;; Note 1 + 1. Lookup the IPv6 DA in the mapping table + 2. update the IPv6 DA with the new mapped SID ;; Ref1 3. IF segment_list > 1 4. insert a new SRH 5. forward according to the new mapped SID - 6. ELSE - 7. Drop the packet - Note 1: The SID in the SRH is NOT modified. + Ref1: The SIDs in the SRH are NOT modified. 6.3. End.M.GTP6.D The "Endpoint function with IPv6/GTP decapsulation into SR policy" function (End.M.GTP6.D for short) is used in interworking scenario for the uplink toward from the legacy gNB using IPv6/GTP. Suppose, for example, this SID is associated with an SR policy and an IPv6 Source Address A. When the SR Gateway node N receives a packet destined to S and S is a local End.M.GTP6.D SID, N does: - 1. IF NH=UDP & UDP_PORT = GTP THEN - 2. pop the IPv6, UDP and GTP headers - 3. push a new IPv6 header with its own SRH - 4. set the outer IPv6 SA to A - 5. set the outer IPv6 DA to S1 - 6. forward according to the S1 segment of the SRv6 Policy - 7. ELSE - 8. Drop the packet + 1. IF NH=UDP & UDP_DST_PORT = GTP THEN + 2. copy TEID to form SID S3 + 3. pop the IPv6, UDP and GTP headers + 4. push a new IPv6 header with a SR policy in SRH + 5. set the outer IPv6 SA to A + 6. set the outer IPv6 DA to S1 + 7. set the outer IPv6 NH ;; Ref1 + 8. forward according to the S1 segment of the SRv6 Policy + 9. ELSE + 10. Drop the packet + + Ref1: The NH is set based on the SID parameter. There is one + instantiation of the End.M.GTP6.D SID per PDU Session Type, hence the + NH is already known in advance. For the IPv4v6 PDU Session Type, in + addition we inspect the first nibble of the PDU to know the NH value. + + The prefix of last segment(S3 in above example) SHOULD be followed by + an Arg.Mob.Session argument space which is used to provide the + session identifiers. + + The prefix of A SHOULD be an End.M.GTP6.E SID instantiated at an SR + gateway. 6.4. End.M.GTP6.E The "Endpoint function with encapsulation for IPv6/GTP tunnel" function (End.M.GTP6.E for short) is used in interworking scenario for the downlink toward the legacy gNB using IPv6/GTP. - The End.M.GTP6.E function has a 32-bit argument space which is used - to provide the GTP TEID. + The prefix of End.M.GTP6.E SID MUST be followed by the + Arg.Mob.Session argument space which is used to provide the session + identifiers. When the SR Gateway node N receives a packet destined to S, and S is a local End.M.GTP6.E SID, N does the following: - 1. IF NH=SRH & SL = 1 THEN ;; Note 1 - 2. decrement SL - 3. store SRH[SL] in variable new_DA - 4. store TEID in variable new_TEID ;; Note 2 - 5. pop IP header and all its extension headers - 6. push new IPv6 header and GTP-U header - 7. set IPv6 DA to new_DA + 1. IF NH=SRH & SL = 1 THEN ;; Ref1 + 2. store SRH[0] in variable new_DA + 3. store TEID in variable new_TEID from IPv6 DA ;; Ref2 + 4. pop IP header and all its extension headers + 5. push new IPv6 header and GTP-U header + 6. set IPv6 DA to new_DA + 7. set IPv6 SA to A 8. set GTP_TEID to new_TEID 9. lookup the new_DA and forward the packet accordingly 10. ELSE 11. Drop the packet - Note 1: An End.M.GTP6.E SID MUST always be the penultimate SID. + Ref1: An End.M.GTP6.E SID MUST always be the penultimate SID. - Note 2: TEID is extracted from the argument space of the current SID. + Ref2: TEID is extracted from the argument space of the current SID. + + The source address A SHOULD be an End.M.GTP6.D SID instantiated at an + SR gateway. 6.5. End.M.GTP4.E The "Endpoint function with encapsulation for IPv4/GTP tunnel" function (End.M.GTP4.E for short) is used in the downlink when doing interworking with legacy gNB using IPv4/GTP. When the SR Gateway node N receives a packet destined to S and S is a local End.M.GTP4.E SID, N does: - 1. IF NH=SRH & SL = 0 THEN - 2. store SRH[0] in buffer S - 3. pop the IPv6 header and its extension headers - 4. push UDP/GTP headers with GTP TEID from S - 5. push outer IPv4 header with SA, DA from S - 6. ELSE - 7. Drop the packet + 1. IF (NH=SRH and SL = 0) or ENH=4 THEN + 2. store IPv6 DA in buffer S + 3. store IPv6 SA in buffer S' + 4. pop the IPv6 header and its extension headers + 5. push UDP/GTP headers with GTP TEID from S + 6. push outer IPv4 header with SA, DA from S' and S + 7. ELSE + 8. Drop the packet - S has the following format: + The End.M.GTP4.E SID in S has the following format: - +----------------------+-------+-------+-------+ - | SRGW-IPv6-LOC-FUNC |IPv4DA |IPv4SA |TUN-ID | - +----------------------+-------+-------+-------+ + 0 127 + +-----------------------+-------+----------------+---------+ + | SRGW-IPv6-LOC-FUNC |IPv4DA |Args.Mob.Session|0 Padded | + +-----------------------+-------+----------------+---------+ 128-a-b-c a b c End.M.GTP4.E SID Encoding -6.6. T.M.Tmap + S' has the following format: + + 0 127 + +----------------------+--------+--------------------------+ + | Source UPF Prefix |IPv4 SA | any bit pattern(ignored) | + +----------------------+--------+--------------------------+ + 128-a-b a b + + IPv6 SA Encoding for End.M.GTP4.E + +6.6. T.M.GTP4.D The "Transit with tunnel decapsulation and map to an SRv6 policy" - function (T.M.Tmap for short) is used in the direction from legacy + function (T.M.GTP4.D for short) is used in the direction from legacy user-plane to SRv6 user-plane network. When the SR Gateway node N receives a packet destined to a IW- IPv4-Prefix, N does: 1. IF Payload == UDP/GTP THEN 2. pop the outer IPv4 header and UDP/GTP headers - 3. copy IPv4 DA, SA, TUN-ID to form SID B - 4. encapsulate the packet into a new IPv6 header - 5. set the IPv6 DA = B - 6. forward along the shortest path to B - 7. ELSE - 8. Drop the packet + 3. copy IPv4 DA, TEID to form SID B + 4. copy IPv4 SA to form IPv6 SA B' + 5. encapsulate the packet into a new IPv6 header ;;Ref1 + 6. set the IPv6 DA = B + 7. forward along the shortest path to B + 8. ELSE + 9. Drop the packet - B has the following format: + Ref1: The NH value is identified by inspecting the first nibble of + the inner payload. - +----------------------+-------+-------+-------+ - | SRGW-IPv6-LOC-FUNC |IPv4DA |IPv4SA |TUN-ID | - +----------------------+-------+-------+-------+ + The SID B has the following format: + + 0 127 + +-----------------------+-------+----------------+---------+ + |Destination UPF Prefix |IPv4DA |Args.Mob.Session|0 Padded | + +-----------------------+-------+----------------+---------+ 128-a-b-c a b c - End.M.GTP4.E SID Encoding + T.M.GTP4.D SID Encoding - The SID B is an SRv6 BindingSID instantiated at the first UPF (U1). - A static format is used for this Binding SIDs in order to remove - state from the SRGW. + The SID B MAY be an SRv6 Binding SID instantiated at the first UPF + (U1) to bind a SR policy [I-D.ietf-spring-segment-routing-policy]. + + The prefix of B' SHOULD be an End.M.GTP4.E SID with its format + instantiated at an SR gateway with the IPv4 SA of the receiving + packet. 6.7. End.Limit: Rate Limiting function The mobile user-plane requires a rate-limit feature. For this purpose, we define a new function "End.Limit". The "End.Limit" function encodes in its arguments the rate limiting parameter that should be applied to this packet. Multiple flows of packets should have the same group identifier in the SID when those flows are in an same AMBR group. The encoding format of the rate limit segment SID is as follows: @@ -985,30 +1018,30 @@ for IPv4 PDU sessions; End.DX6, End.DT6, End.T for IPv6 PDU sessions; End.DT46 for IPv4v6 PDU sessions; End.DX2 for L2 PDU sessions; End.DX2 for Unstructured PDU sessions). 8. Network Slicing Considerations A mobile network may be required to implement "network slices", which logically separate network resources. User-plane functions represented as SRv6 segments would be part of a slice. - [I-D.filsfils-spring-segment-routing-policy] describes a solution to + [I-D.ietf-spring-segment-routing-policy] describes a solution to build basic network slices with SR. Depending on the requirements, these slices can be further refined by adopting the mechanisms from: o IGP Flex-Algo [I-D.hegdeppsenak-isis-sr-flex-algo] o Inter-Domain policies [I-D.ietf-spring-segment-routing-central-epe] Furthermore, these can be combined with ODN/AS - [I-D.filsfils-spring-segment-routing-policy] for automated slice + [I-D.ietf-spring-segment-routing-policy] for automated slice provisioning and traffic steering. Further details on how these tools can be used to create end to end network slices are documented in [I-D.ali-spring-network-slicing-building-blocks]. 9. Control Plane Considerations This document focuses on user-plane behavior and its independence from the control plane. @@ -1032,21 +1065,21 @@ 10. Security Considerations TBD 11. IANA Considerations IANA is requested to allocate, within the "SRv6 Endpoint Types" sub- registry belonging to the top-level "Segment-routing with IPv6 dataplane (SRv6) Parameters" registry - [I-D.filsfils-spring-srv6-network-programming], the following values: + [I-D.ietf-spring-srv6-network-programming], the following values: +-------------+-----+-------------------+-----------+ | Value/Range | Hex | Endpoint function | Reference | +-------------+-----+-------------------+-----------+ | TBA | TBA | End.MAP | [This.ID] | | TBA | TBA | End.M.GTP6.D | [This.ID] | | TBA | TBA | End.M.GTP6.E | [This.ID] | | TBA | TBA | End.M.GTP4.E | [This.ID] | | TBA | TBA | End.Limit | [This.ID] | +-------------+-----+-------------------+-----------+ @@ -1056,86 +1089,77 @@ 12. Acknowledgements The authors would like to thank Daisuke Yokota, Bart Peirens, Ryokichi Onishi, Kentaro Ebisawa, Peter Bosch, Darren Dukes, Francois Clad, Sri Gundavelli, Sridhar Bhaskaran, Arashmid Akhavain, Ravi Shekhar and Aeneas Dodd-Noble for their useful comments of this work. 13. Contributors Kentaro Ebisawa - Ponto Networks + Toyota Motor Corporation Japan - Email: ebiken@pontonetworks.com + + Email: ebisawa@toyota-tokyo.tech 14. References 14.1. Normative References - [I-D.filsfils-spring-segment-routing-policy] - Filsfils, C., Sivabalan, S., Hegde, S., - daniel.voyer@bell.ca, d., Lin, S., bogdanov@google.com, - b., Krol, P., Horneffer, M., Steinberg, D., Decraene, B., - Litkowski, S., Mattes, P., Ali, Z., Talaulikar, K., Liste, - J., Clad, F., and K. Raza, "Segment Routing Policy - Architecture", draft-filsfils-spring-segment-routing- - policy-06 (work in progress), May 2018. + [I-D.ietf-6man-segment-routing-header] + Filsfils, C., Dukes, D., Previdi, S., Leddy, J., + Matsushima, S., and d. daniel.voyer@bell.ca, "IPv6 Segment + Routing Header (SRH)", draft-ietf-6man-segment-routing- + header-21 (work in progress), June 2019. - [I-D.filsfils-spring-srv6-network-programming] + [I-D.ietf-spring-segment-routing-policy] + Filsfils, C., Sivabalan, S., daniel.voyer@bell.ca, d., + bogdanov@google.com, b., and P. Mattes, "Segment Routing + Policy Architecture", draft-ietf-spring-segment-routing- + policy-03 (work in progress), May 2019. + + [I-D.ietf-spring-srv6-network-programming] Filsfils, C., Camarillo, P., Leddy, J., daniel.voyer@bell.ca, d., Matsushima, S., and Z. Li, "SRv6 - Network Programming", draft-filsfils-spring-srv6-network- - programming-07 (work in progress), February 2019. - - [I-D.ietf-6man-segment-routing-header] - Filsfils, C., Previdi, S., Leddy, J., Matsushima, S., and - d. daniel.voyer@bell.ca, "IPv6 Segment Routing Header - (SRH)", draft-ietf-6man-segment-routing-header-16 (work in - progress), February 2019. - - [I-D.voyer-6man-extension-header-insertion] - daniel.voyer@bell.ca, d., Leddy, J., Filsfils, C., Dukes, - D., Previdi, S., and S. Matsushima, "Insertion of IPv6 - Segment Routing Headers in a Controlled Domain", draft- - voyer-6man-extension-header-insertion-05 (work in - progress), January 2019. + Network Programming", draft-ietf-spring-srv6-network- + programming-01 (work in progress), July 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, - DOI 10.17487/RFC2119, March 1997, - . + DOI 10.17487/RFC2119, March 1997, . [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, July 2018, . 14.2. Informative References [I-D.ali-spring-network-slicing-building-blocks] Ali, Z., Filsfils, C., Camarillo, P., and d. daniel.voyer@bell.ca, "Building blocks for Slicing in Segment Routing Network", draft-ali-spring-network- slicing-building-blocks-01 (work in progress), March 2019. [I-D.auge-dmm-hicn-mobility-deployment-options] Auge, J., Carofiglio, G., Muscariello, L., and M. Papalini, "Anchorless mobility management through hICN (hICN-AMM): Deployment options", draft-auge-dmm-hicn- - mobility-deployment-options-01 (work in progress), - December 2018. + mobility-deployment-options-02 (work in progress), July + 2019. [I-D.camarillo-dmm-srv6-mobile-pocs] Camarillo, P., Filsfils, C., Bertz, L., Akhavain, A., Matsushima, S., and d. daniel.voyer@bell.ca, "Segment Routing IPv6 for mobile user-plane PoCs", draft-camarillo- - dmm-srv6-mobile-pocs-01 (work in progress), October 2018. + dmm-srv6-mobile-pocs-02 (work in progress), April 2019. [I-D.camarilloelmalky-springdmm-srv6-mob-usecases] Camarillo, P., Filsfils, C., Elmalky, H., Matsushima, S., daniel.voyer@bell.ca, d., Cui, A., and B. Peirens, "SRv6 Mobility Use-Cases", draft-camarilloelmalky-springdmm- srv6-mob-usecases-01 (work in progress), January 2019. [I-D.gundavelli-dmm-mfa] Gundavelli, S., Liebsch, M., and S. Matsushima, "Mobility- aware Floating Anchor (MFA)", draft-gundavelli-dmm-mfa-01 @@ -1162,67 +1186,49 @@ Rodriguez-Natal, A., Ermagan, V., Maino, F., Dukes, D., Camarillo, P., and C. Filsfils, "LISP Control Plane for SRv6 Endpoint Mobility", draft-rodrigueznatal-lisp-srv6-01 (work in progress), January 2019. [I-D.xuclad-spring-sr-service-programming] Clad, F., Xu, X., Filsfils, C., daniel.bernier@bell.ca, d., Li, C., Decraene, B., Ma, S., Yadlapalli, C., Henderickx, W., and S. Salsano, "Service Programming with Segment Routing", draft-xuclad-spring-sr-service- - programming-01 (work in progress), October 2018. + programming-02 (work in progress), April 2019. [TS.23501] - 3GPP, "System Architecture for the 5G System", 3GPP TS + 3GPP, , "System Architecture for the 5G System", 3GPP TS 23.501 15.0.0, November 2017. [TS.29244] - 3GPP, "Interface between the Control Plane and the User + 3GPP, , "Interface between the Control Plane and the User Plane Nodes", 3GPP TS 29.244 15.0.0, December 2017. [TS.29281] - 3GPP, "General Packet Radio System (GPRS) Tunnelling + 3GPP, , "General Packet Radio System (GPRS) Tunnelling Protocol User Plane (GTPv1-U)", 3GPP TS 29.281 15.1.0, December 2017. [TS.38415] - 3GPP, "Draft Specification for 5GS container (TS 38.415)", - 3GPP R3-174510 0.0.0, August 2017. + 3GPP, , "Draft Specification for 5GS container (TS + 38.415)", 3GPP R3-174510 0.0.0, August 2017. Appendix A. Implementations This document introduces new SRv6 functions. These functions have an open-source P4 implementation available in . There are also implementations in M-CORD NGIC and Open Air Interface (OAI). Further details can be found in [I-D.camarillo-dmm-srv6-mobile-pocs]. -Appendix B. Changes from revision 02 to revision 03 - - This section lists the changes between draft-ietf-dmm-srv6-mobile- - uplane revisions ...-02 and ...-03. - - o Added new terminology section for abbreviations. - o Added new terminology section for predefined SRv6 functions. - o Made terminology section for conventions used in the document. - - o Renamed "Basic" mode to be called "Traditional" mode. - o Renamed "Aggregate" mode to be called "Enhanced" mode. - o Added new Args.Mob.Session format to supply QFI, RQI indication - and PDU Session ID. - o Modified End.MAP function to define the SID argument format and - support more than one SID - o Added missing references. - o Editorial updates to improve readability. - Authors' Addresses Satoru Matsushima SoftBank Tokyo Japan Email: satoru.matsushima@g.softbank.co.jp Clarence Filsfils