draft-ietf-dmm-srv6-mobile-uplane-05.txt   draft-ietf-dmm-srv6-mobile-uplane-06.txt 
DMM Working Group S. Matsushima DMM Working Group S. Matsushima
Internet-Draft SoftBank Internet-Draft SoftBank
Intended status: Standards Track C. Filsfils Intended status: Standards Track C. Filsfils
Expires: January 9, 2020 M. Kohno Expires: March 29, 2020 M. Kohno
P. Camarillo P. Camarillo
Cisco Systems, Inc. Cisco Systems, Inc.
D. Voyer D. Voyer
Bell Canada Bell Canada
C. Perkins C. Perkins
Futurewei Futurewei
July 8, 2019 September 26, 2019
Segment Routing IPv6 for Mobile User Plane Segment Routing IPv6 for Mobile User Plane
draft-ietf-dmm-srv6-mobile-uplane-05 draft-ietf-dmm-srv6-mobile-uplane-06
Abstract Abstract
This document shows the applicability of SRv6 (Segment Routing IPv6) This document shows the applicability of SRv6 (Segment Routing IPv6)
to the user-plane of mobile networks. The network programming nature to the user-plane of mobile networks. The network programming nature
of SRv6 accomplish mobile user-plane functions in a simple manner. of SRv6 accomplish mobile user-plane functions in a simple manner.
The statelessness of SRv6 and its ability to control both service The statelessness of SRv6 and its ability to control both service
layer path and underlying transport can be beneficial to the mobile layer path and underlying transport can be beneficial to the mobile
user-plane, providing flexibility, end-to-end network slicing and SLA user-plane, providing flexibility, end-to-end network slicing and SLA
control for various applications. This document describes the SRv6 control for various applications. This document describes the SRv6
mobile user plane behavior and defines the SID functions for that. mobile user plane behavior and defines the SID functions for that.
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
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This Internet-Draft will expire on January 9, 2020. This Internet-Draft will expire on March 29, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3 2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Predefined SRv6 Functions . . . . . . . . . . . . . . . . 4 2.3. Predefined SRv6 Functions . . . . . . . . . . . . . . . . 4
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. A 3GPP Reference Architecture . . . . . . . . . . . . . . . . 6 4. A 3GPP Reference Architecture . . . . . . . . . . . . . . . . 6
5. User-plane behaviors . . . . . . . . . . . . . . . . . . . . 7 5. User-plane behaviors . . . . . . . . . . . . . . . . . . . . 7
5.1. Traditional mode . . . . . . . . . . . . . . . . . . . . 7 5.1. Traditional mode . . . . . . . . . . . . . . . . . . . . 7
5.1.1. Packet flow - Uplink . . . . . . . . . . . . . . . . 8 5.1.1. Packet flow - Uplink . . . . . . . . . . . . . . . . 8
5.1.2. Packet flow - Downlink . . . . . . . . . . . . . . . 8 5.1.2. Packet flow - Downlink . . . . . . . . . . . . . . . 8
5.1.3. IPv6 user-traffic . . . . . . . . . . . . . . . . . . 9
5.2. Enhanced Mode . . . . . . . . . . . . . . . . . . . . . . 9 5.2. Enhanced Mode . . . . . . . . . . . . . . . . . . . . . . 9
5.2.1. Packet flow - Uplink . . . . . . . . . . . . . . . . 10 5.2.1. Packet flow - Uplink . . . . . . . . . . . . . . . . 10
5.2.2. Packet flow - Downlink . . . . . . . . . . . . . . . 11 5.2.2. Packet flow - Downlink . . . . . . . . . . . . . . . 10
5.2.3. IPv6 user-traffic . . . . . . . . . . . . . . . . . . 11
5.3. Enhanced mode with unchanged gNB GTP behavior . . . . . . 11 5.3. Enhanced mode with unchanged gNB GTP behavior . . . . . . 11
5.3.1. Interworking with IPv6 GTP . . . . . . . . . . . . . 12 5.3.1. Interworking with IPv6 GTP . . . . . . . . . . . . . 11
5.3.2. Interworking with IPv4 GTP . . . . . . . . . . . . . 15 5.3.2. Interworking with IPv4 GTP . . . . . . . . . . . . . 14
5.3.3. Extensions to the interworking mechanisms . . . . . . 17 5.3.3. Extensions to the interworking mechanisms . . . . . . 17
6. SRv6 SID Mobility Functions . . . . . . . . . . . . . . . . . 18 6. SRv6 SID Mobility Functions . . . . . . . . . . . . . . . . . 17
6.1. Args.Mob.Session . . . . . . . . . . . . . . . . . . . . 18 6.1. Args.Mob.Session . . . . . . . . . . . . . . . . . . . . 17
6.2. End.MAP . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.2. End.MAP . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.3. End.M.GTP6.D . . . . . . . . . . . . . . . . . . . . . . 19 6.3. End.M.GTP6.D . . . . . . . . . . . . . . . . . . . . . . 18
6.4. End.M.GTP6.E . . . . . . . . . . . . . . . . . . . . . . 19 6.4. End.M.GTP6.E . . . . . . . . . . . . . . . . . . . . . . 19
6.5. End.M.GTP4.E . . . . . . . . . . . . . . . . . . . . . . 20 6.5. End.M.GTP4.E . . . . . . . . . . . . . . . . . . . . . . 20
6.6. T.M.GTP4.D . . . . . . . . . . . . . . . . . . . . . . . 21 6.6. T.M.GTP4.D . . . . . . . . . . . . . . . . . . . . . . . 20
6.7. End.Limit: Rate Limiting function . . . . . . . . . . . . 22 6.7. End.Limit: Rate Limiting function . . . . . . . . . . . . 21
7. SRv6 supported 3GPP PDU session types . . . . . . . . . . . . 22 7. SRv6 supported 3GPP PDU session types . . . . . . . . . . . . 22
8. Network Slicing Considerations . . . . . . . . . . . . . . . 23 8. Network Slicing Considerations . . . . . . . . . . . . . . . 22
9. Control Plane Considerations . . . . . . . . . . . . . . . . 23 9. Control Plane Considerations . . . . . . . . . . . . . . . . 22
10. Security Considerations . . . . . . . . . . . . . . . . . . . 24 10. Security Considerations . . . . . . . . . . . . . . . . . . . 23
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 24 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 24
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 24
14.1. Normative References . . . . . . . . . . . . . . . . . . 24 14.1. Normative References . . . . . . . . . . . . . . . . . . 24
14.2. Informative References . . . . . . . . . . . . . . . . . 25 14.2. Informative References . . . . . . . . . . . . . . . . . 24
Appendix A. Implementations . . . . . . . . . . . . . . . . . . 27 Appendix A. Implementations . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction 1. Introduction
In mobile networks, mobility management systems provide connectivity In mobile networks, mobility management systems provide connectivity
while mobile nodes move. While the control-plane of the system while mobile nodes move. While the control-plane of the system
signals movements of a mobile node, the user-plane establishes a signals movements of a mobile node, the user-plane establishes a
tunnel between the mobile node and its anchor node over IP-based tunnel between the mobile node and its anchor node over IP-based
backhaul and core networks. backhaul and core networks.
This document shows the applicability of SRv6 (Segment Routing IPv6) This document shows the applicability of SRv6 (Segment Routing IPv6)
skipping to change at page 9, line 25 skipping to change at page 9, line 25
Upon packet arrival on UPF1, the SID U1::1 is a local End.MAP 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 function. This function maps the SID to the next anchoring point and
replaces U1::1 by gNB::1, that belongs to the next hop. 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 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 or End.DX6 function. The gNB decapsulates the packet, removing the
IPv6 header and all its extensions headers, and forwards the traffic IPv6 header and all its extensions headers, and forwards the traffic
toward the UE. 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. 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 5.2. Enhanced Mode
Enhanced mode improves scalability, traffic steering and service Enhanced mode improves scalability, traffic steering and service
programming [I-D.xuclad-spring-sr-service-programming], thanks to the programming [I-D.xuclad-spring-sr-service-programming], thanks to the
use of multiple SIDs, instead of a single SID as done in the use of multiple SIDs, instead of a single SID as done in the
Traditional mode. Traditional mode.
The main difference is that the SR policy MAY include SIDs for The main difference is that the SR policy MAY include SIDs for
traffic engineering and service programming in addition to the UPFs traffic engineering and service programming in addition to the UPFs
SIDs. SIDs.
skipping to change at page 11, line 29 skipping to change at page 11, line 25
operation, encapsulating the packet into a new IPv6 header with its operation, encapsulating the packet into a new IPv6 header with its
corresponding SRH. corresponding SRH.
The nodes C1 and S1 perform their related Endpoint processing. The nodes C1 and S1 perform their related Endpoint processing.
Once the packet arrives at the gNB, the IPv6 DA corresponds to an 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 End.DX4 or End.DX6 (depending on the underlying traffic). The gNB
decapsulates the packet, removing the IPv6 header and all its decapsulates the packet, removing the IPv6 header and all its
extensions headers and forwards the traffic toward the UE. extensions headers and forwards the traffic toward the UE.
5.2.3. 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. The main benefit is a lower overhead. In such case,
the functions used are T.Insert.Red at gNB and End.T at UPF2 on
Uplink, T.Insert.Red at UPF2 and End.X at gNB on Downlink.
5.3. Enhanced mode with unchanged gNB GTP behavior 5.3. Enhanced mode with unchanged gNB GTP behavior
This section describes two mechanisms for interworking with legacy This section describes two mechanisms for interworking with legacy
gNBs that still use GTP: one for IPv4, the other for IPv6. gNBs that still use GTP: one for IPv4, the other for IPv6.
In the interworking scenarios as illustrated in Figure 4, gNB does In the interworking scenarios as illustrated in Figure 4, gNB does
not support SRv6. gNB supports GTP encapsulation over IPv4 or IPv6. not support SRv6. gNB supports GTP encapsulation over IPv4 or IPv6.
To achieve interworking, a SR Gateway (SRGW-UPF1) entity is added. To achieve interworking, a SR Gateway (SRGW-UPF1) entity is added.
The SRGW maps the GTP traffic into SRv6. The SRGW maps the GTP traffic into SRv6.
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Email: ebisawa@toyota-tokyo.tech Email: ebisawa@toyota-tokyo.tech
14. References 14. References
14.1. Normative References 14.1. Normative References
[I-D.ietf-6man-segment-routing-header] [I-D.ietf-6man-segment-routing-header]
Filsfils, C., Dukes, D., Previdi, S., Leddy, J., Filsfils, C., Dukes, D., Previdi, S., Leddy, J.,
Matsushima, S., and d. daniel.voyer@bell.ca, "IPv6 Segment Matsushima, S., and d. daniel.voyer@bell.ca, "IPv6 Segment
Routing Header (SRH)", draft-ietf-6man-segment-routing- Routing Header (SRH)", draft-ietf-6man-segment-routing-
header-21 (work in progress), June 2019. header-23 (work in progress), September 2019.
[I-D.ietf-spring-segment-routing-policy] [I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Sivabalan, S., daniel.voyer@bell.ca, d., Filsfils, C., Sivabalan, S., daniel.voyer@bell.ca, d.,
bogdanov@google.com, b., and P. Mattes, "Segment Routing bogdanov@google.com, b., and P. Mattes, "Segment Routing
Policy Architecture", draft-ietf-spring-segment-routing- Policy Architecture", draft-ietf-spring-segment-routing-
policy-03 (work in progress), May 2019. policy-03 (work in progress), May 2019.
[I-D.ietf-spring-srv6-network-programming] [I-D.ietf-spring-srv6-network-programming]
Filsfils, C., Camarillo, P., Leddy, J., Filsfils, C., Camarillo, P., Leddy, J.,
daniel.voyer@bell.ca, d., Matsushima, S., and Z. Li, "SRv6 daniel.voyer@bell.ca, d., Matsushima, S., and Z. Li, "SRv6
Network Programming", draft-ietf-spring-srv6-network- Network Programming", draft-ietf-spring-srv6-network-
programming-01 (work in progress), July 2019. programming-02 (work in progress), September 2019.
[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, <https://www.rfc- DOI 10.17487/RFC2119, March 1997,
editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>. July 2018, <https://www.rfc-editor.org/info/rfc8402>.
14.2. Informative References 14.2. Informative References
[I-D.ali-spring-network-slicing-building-blocks] [I-D.ali-spring-network-slicing-building-blocks]
Ali, Z., Filsfils, C., Camarillo, P., and d. Ali, Z., Filsfils, C., Camarillo, P., and d.
skipping to change at page 26, line 9 skipping to change at page 25, line 22
[I-D.camarillo-dmm-srv6-mobile-pocs] [I-D.camarillo-dmm-srv6-mobile-pocs]
Camarillo, P., Filsfils, C., Bertz, L., Akhavain, A., Camarillo, P., Filsfils, C., Bertz, L., Akhavain, A.,
Matsushima, S., and d. daniel.voyer@bell.ca, "Segment Matsushima, S., and d. daniel.voyer@bell.ca, "Segment
Routing IPv6 for mobile user-plane PoCs", draft-camarillo- Routing IPv6 for mobile user-plane PoCs", draft-camarillo-
dmm-srv6-mobile-pocs-02 (work in progress), April 2019. dmm-srv6-mobile-pocs-02 (work in progress), April 2019.
[I-D.camarilloelmalky-springdmm-srv6-mob-usecases] [I-D.camarilloelmalky-springdmm-srv6-mob-usecases]
Camarillo, P., Filsfils, C., Elmalky, H., Matsushima, S., Camarillo, P., Filsfils, C., Elmalky, H., Matsushima, S.,
daniel.voyer@bell.ca, d., Cui, A., and B. Peirens, "SRv6 daniel.voyer@bell.ca, d., Cui, A., and B. Peirens, "SRv6
Mobility Use-Cases", draft-camarilloelmalky-springdmm- Mobility Use-Cases", draft-camarilloelmalky-springdmm-
srv6-mob-usecases-01 (work in progress), January 2019. srv6-mob-usecases-02 (work in progress), August 2019.
[I-D.gundavelli-dmm-mfa] [I-D.gundavelli-dmm-mfa]
Gundavelli, S., Liebsch, M., and S. Matsushima, "Mobility- Gundavelli, S., Liebsch, M., and S. Matsushima, "Mobility-
aware Floating Anchor (MFA)", draft-gundavelli-dmm-mfa-01 aware Floating Anchor (MFA)", draft-gundavelli-dmm-mfa-01
(work in progress), September 2018. (work in progress), September 2018.
[I-D.hegdeppsenak-isis-sr-flex-algo] [I-D.hegdeppsenak-isis-sr-flex-algo]
Psenak, P., Hegde, S., Filsfils, C., and A. Gulko, "ISIS Psenak, P., Hegde, S., Filsfils, C., and A. Gulko, "ISIS
Segment Routing Flexible Algorithm", draft-hegdeppsenak- Segment Routing Flexible Algorithm", draft-hegdeppsenak-
isis-sr-flex-algo-02 (work in progress), February 2018. isis-sr-flex-algo-02 (work in progress), February 2018.
skipping to change at page 26, line 36 skipping to change at page 25, line 49
[I-D.ietf-spring-segment-routing-central-epe] [I-D.ietf-spring-segment-routing-central-epe]
Filsfils, C., Previdi, S., Dawra, G., Aries, E., and D. Filsfils, C., Previdi, S., Dawra, G., Aries, E., and D.
Afanasiev, "Segment Routing Centralized BGP Egress Peer Afanasiev, "Segment Routing Centralized BGP Egress Peer
Engineering", draft-ietf-spring-segment-routing-central- Engineering", draft-ietf-spring-segment-routing-central-
epe-10 (work in progress), December 2017. epe-10 (work in progress), December 2017.
[I-D.rodrigueznatal-lisp-srv6] [I-D.rodrigueznatal-lisp-srv6]
Rodriguez-Natal, A., Ermagan, V., Maino, F., Dukes, D., Rodriguez-Natal, A., Ermagan, V., Maino, F., Dukes, D.,
Camarillo, P., and C. Filsfils, "LISP Control Plane for Camarillo, P., and C. Filsfils, "LISP Control Plane for
SRv6 Endpoint Mobility", draft-rodrigueznatal-lisp-srv6-01 SRv6 Endpoint Mobility", draft-rodrigueznatal-lisp-srv6-02
(work in progress), January 2019. (work in progress), July 2019.
[I-D.xuclad-spring-sr-service-programming] [I-D.xuclad-spring-sr-service-programming]
Clad, F., Xu, X., Filsfils, C., daniel.bernier@bell.ca, Clad, F., Xu, X., Filsfils, C., daniel.bernier@bell.ca,
d., Li, C., Decraene, B., Ma, S., Yadlapalli, C., d., Li, C., Decraene, B., Ma, S., Yadlapalli, C.,
Henderickx, W., and S. Salsano, "Service Programming with Henderickx, W., and S. Salsano, "Service Programming with
Segment Routing", draft-xuclad-spring-sr-service- Segment Routing", draft-xuclad-spring-sr-service-
programming-02 (work in progress), April 2019. programming-02 (work in progress), April 2019.
[TS.23501] [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. 23.501 15.0.0, November 2017.
[TS.29244] [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. Plane Nodes", 3GPP TS 29.244 15.0.0, December 2017.
[TS.29281] [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, Protocol User Plane (GTPv1-U)", 3GPP TS 29.281 15.1.0,
December 2017. December 2017.
[TS.38415] [TS.38415]
3GPP, , "Draft Specification for 5GS container (TS 3GPP, "Draft Specification for 5GS container (TS 38.415)",
38.415)", 3GPP R3-174510 0.0.0, August 2017. 3GPP R3-174510 0.0.0, August 2017.
Appendix A. Implementations Appendix A. Implementations
This document introduces new SRv6 functions. These functions have an This document introduces new SRv6 functions. These functions have an
open-source P4 implementation available in open-source P4 implementation available in
<https://github.com/ebiken/p4srv6>. <https://github.com/ebiken/p4srv6>.
There are also implementations in M-CORD NGIC and Open Air Interface There are also implementations in M-CORD NGIC and Open Air Interface
(OAI). Further details can be found in (OAI). Further details can be found in
[I-D.camarillo-dmm-srv6-mobile-pocs]. [I-D.camarillo-dmm-srv6-mobile-pocs].
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