Internet DRAFT - draft-filsfils-spring-net-pgm-srv6-usid-illus
draft-filsfils-spring-net-pgm-srv6-usid-illus
SPRING C. Filsfils, Ed.
Internet-Draft P. Camarillo, Ed.
Intended status: Informational Cisco Systems, Inc.
Expires: August 28, 2020 D. Cai
Alibaba
D. Voyer
Bell Canada
I. Meilik
Broadcom
K. Patel
Arrcus, Inc.
W. Henderickx
Nokia
P. Jonnalagadda
Barefoot Networks
D. Melman
Marvell
February 25, 2020
NET-PGM extension: SRv6 uSID illustration
draft-filsfils-spring-net-pgm-srv6-usid-illus-00
Abstract
This document illustrates the SRv6 "micro segment" (SRv6 uSID or uSID
for short) instruction.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 28, 2020.
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Internet-Draft NET-PGM extension: SRv6 uSID illustration February 2020
Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Illustration . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1. Reference diagram . . . . . . . . . . . . . . . . . . . . 3
2.2. SRv6 overlay with underlay optimization . . . . . . . . . 3
3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
4. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 5
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
SRv6 Network Programming [I-D.ietf-spring-srv6-network-programming]
defines a mechanism to build a network program with topological and
service segments. It leverages the SRH
[I-D.ietf-6man-segment-routing-header] to encode a network program
together with optional metadata shared among the different SIDs.
[I-D.filsfils-spring-net-pgm-extension-srv6-usid] draft extends SRv6
Network Programming with a new type of SRv6 SID behavior: SRv6 uN.
This document illustrates it.
2. Illustration
This section extends the illustrations for SRv6 Network Programming
[I-D.filsfils-spring-srv6-net-pgm-illustration] to cover uSID. The
reference topology is the same with the addition of link 6-8.
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2.1. Reference diagram
Nodes 1 to 8 are considered within the network domain.
Nodes X and Y are outside the domain.
Nodes 1 and 8 act as PE respectively to nodes X and Y.
All the links within the domain have the same IGP metric. The IGP-
metric shortest-path from 1 to 8 is 1-2-7-8 while the latency-metric
shortest-path from 1 to 8 is 1-2-3-4-5-6-7-8.
3------4---5
| \ /
| 6
| / \
1--- 2------7---8
/ \
X Y
Tenant100 Tenant100 with
IPv4 20/8
Figure 1: Reference topology
2.2. SRv6 overlay with underlay optimization
Let us illustrate a low-latency SR-L3VPN service delivered to a
packet (X,Y).
PE 1 encapsulates (X, Y) in an outer IPv6 header with DA =
2001:db8:0300:0500:0700:: and SRH (B:8:D0::; SL=1; NH=4). Leveraging
the illustration conventions from SRv6 network programming, the
following resulting packet leaves node 1 in the direction of node 3:
(A1::, 2001:db8:0300:0500:0700::)(B:8:D0::; SL=1; NH=4)(X, Y)
2001:db8:0300:0500:0700:: is a uSID carrier encoding a source routed
stateless path via node 3 then 5 then 7.
B:8:D0:: is an End.DT4 SID instantiated at node 8.
1 sends this packet to 2, as 2 is on the shortest-path to
2001:db8:0300::/48 advertised by 3.
When 2 receives the packet, 2 performs a regular IPv6 FIB lookup. It
finds a FIB entry for 2001:db8:0300::/48 and forwards along the
shortest path to 3.
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When 3 receives the packet, 3 matches 2001:db8:0300::/48 in its "My
SID Table" and executes the uN behavior. The updated DA becomes
2001:db8:0500:0700::. Node 3 then performs a lookup on the updated DA
and forwards the packet to 5 along the shortest path to
2001:db8:0500::/48.
The following packet leaves node 3:
(A1::, 2001:db8:0500:0700::)(B:8:D0::; SL=1; NH=4)(X, Y)
4 forwards along the shortest path to 2001:db8:0500::/48.
When 5 receives the packet, 5 matches 2001:db8:0500::/48 in its "My
SID Table" and executes the uN behavior. The updated DA becomes
2001:db8:0700::. 5 performs a lookup on the updated DA and forwards
the packet to 7 along the shortest path to 2001:db8:0700::/48.
The following packet leaves node 5:
(A1::, 2001:db8:0700::)(B:8:D0::; SL=1; NH=4)(X, Y)
6 forwards along the shortest path to 2001:db8:0700::/48.
When 7 receives the packet, 7 matches 2001:db8:0700::/48 in its "My
SID Table" and finds the bound function uN. As a result, Node 7
executes the "End with PSP and USD support" pseudocode, decrementing
the SL value in the SRH, and updating the DA with the next SID
B:8:D0::. Since the SL value is zero the SRH is removed. Node 7
performs a lookup on the updated DA and forwards along the shortest
path.
The following packet leaves node 7:
(A1::, B:8:D0::)(X, Y)
8 receives it, performs the End.DT4 function and sends the IP packet
(X, Y) towards its VPN destination.
This example illustrates the benefits highlighted in the next
section.
3. Acknowledgements
The authors would like to acknowledge Francois Clad, Peter Psenak,
Ketan Talaulikar, Jakub Horn, Swadesh Agrawal, Zafar Ali, Darren
Dukes, Kiran Sadshiran, Junaid Israr, Lakshmanan Srikanth, Asif
Islam, Saleem Hafeez, Michael MacKenzie, Sushek Shekar, YuanChao Su,
Alexander Preusche, Alberto Donzelli, Miya Kohno, David Smith, Ianik
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Semco, Bertrand Duvivier, Frederic Trate, Kris Michielsen, Eyal
Dagan, Eli Stein, Ofer Iny, Elad Naor, Aviad Behar, Joseph Chin.
4. Contributors
Jisu Bhattacharyaa
Cisco Systems, Inc.
United States of America
Email: jisu@cisco.com
Kamran Raza
Cisco Systems, Inc.
Canada
Email: skraza@cisco.com
John Bettink
Cisco Systems, Inc.
United States of America
Email: jbettink@cisco.com
Tomonobu Niwa
KDDI
Japan
Email: to-niwa@kddi.com
Luay Jalil
Verizon
United States of America
Email: luay.jalil@one.verizon.com
Zhichun Jiang
Tencent
China
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Email: zcjiang@tencent.com
Ahmed Shawky
Saudi Telecom Company
Saudi Arabia
Email: ashawky@stc.com.sa
Nic Leymann
Deutsche Telekom
Germany
Email: N.Leymann@telekom.de
Dirk Steinberg
Lapishills Consulting Limited
Cyprus
Email: dirk@lapishills.com
Shawn Zandi
LinkedIn
United States of America
Email: szandi@linkedin.com
Gaurav Dawra
LinkedIn
United States of America
Email: gdawra@linkedin.com
Jim Uttaro
AT&T
United States of America
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Email: ju1738@att.com
Ning So
Reliance
United States of America
Email: Ning.So@ril.com
Michael Fiumano
Sprint
United States of America
Email: michael.f.fiumano@sprint.com
Mazen Khaddam
Cox
United States of America
Email: Mazen.Khaddam@cox.com
Jichun Ma
China Unicom
China
Email: majc16@chinaunicom.cn
Satoru Matsushima
Softbank
Japan
Email: satoru.matsushima@g.softbank.co.jp
Francis Ferguson
CenturyLink
United States of America
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Email: Francis.Ferguson@centurylink.com
Takuya Miyasaka
KDDI
Japan
Email: ta-miyasaka@kddi.com
Kentaro Ebisawa
Toyota Motor Corporation
Japan
Email: ebisawa@toyota-tokyo.tech
Yukito Ueno
NTT Communications Corporation
Japan
Email: yukito.ueno@ntt.com
5. References
[I-D.filsfils-spring-net-pgm-extension-srv6-usid]
Filsfils, C., Camarillo, P., Cai, D., Voyer, D., Meilik,
I., Patel, K., Henderickx, W., Jonnalagadda, P., and D.
Melman, "Network Programming extension: SRv6 uSID
instruction", draft-filsfils-spring-net-pgm-extension-
srv6-usid-03 (work in progress), February 2020.
[I-D.filsfils-spring-srv6-net-pgm-illustration]
Filsfils, C., Camarillo, P., Li, Z., Matsushima, S.,
Decraene, B., Steinberg, D., Lebrun, D., Raszuk, R., and
J. Leddy, "Illustrations for SRv6 Network Programming",
draft-filsfils-spring-srv6-net-pgm-illustration-01 (work
in progress), August 2019.
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[I-D.ietf-6man-segment-routing-header]
Filsfils, C., Dukes, D., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", draft-ietf-6man-segment-routing-header-26 (work in
progress), October 2019.
[I-D.ietf-spring-srv6-network-programming]
Filsfils, C., Camarillo, P., Leddy, J., Voyer, D.,
Matsushima, S., and Z. Li, "SRv6 Network Programming",
draft-ietf-spring-srv6-network-programming-10 (work in
progress), February 2020.
Authors' Addresses
Clarence Filsfils (editor)
Cisco Systems, Inc.
Belgium
Email: cf@cisco.com
Pablo Camarillo Garvia (editor)
Cisco Systems, Inc.
Spain
Email: pcamaril@cisco.com
Dennis Cai
Alibaba
China
Email: d.cai@alibaba-inc.com
Daniel Voyer
Bell Canada
Canada
Email: daniel.voyer@bell.ca
Israel Meilik
Broadcom
Israel
Email: israel.meilik@broadcom.com
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Keyur Patel
Arrcus, Inc.
United States of America
Email: keyur@arrcus.com
Wim Henderickx
Nokia
Belgium
Email: wim.henderickx@nokia.com
Prem Jonnalagadda
Barefoot Networks
United States of America
Email: prem@barefootnetworks.com
David Melman
Marvell
Israel
Email: davidme@marvell.com
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