WAN SDN meet Segment Routing

JUNIPER CONFIDENTIAL
SEGMENT ROUTING
FOR SDN
Shaowen Ma, APAC Product Director, Juniper, mashao@juniper.net
March 1, 2017

Juniper Confidential
Introduction
Segment Routing Deep Dive
Segment Routing SDN and Use Case
Summary
AGENDA

MPLS – 16 YEARS, GREAT SUCCESS
THE ACTUAL STANDARD FOR SERVICE DELIVERY
• LDP, mLDP
• RSVP-TE, RSVP-TE P2MP
• L3 MPLS VPN
• 6VPE/6PE
• L2 MPLS VPN – VPWS
• L2 MPLS VPN – VPLS (LDP, BGP, BGP AD)
• Next-generation multicast VPN
• MPLS-OAM, LSP BFD, VCCV Ping, and VCCV-BFD
• MPLS-TP Static LSP/PW, OAM, APS
• GMPLS, GMPLS UNI*
Eric Rosen Yakov RekhterKireeti Kompella Many…
IETF SPRING/Segment Routing working group
• Source Packet Routing in Networking

SDN 2.0 ERA
PE1 ASBR
OpenFlow
Controller
Controller
SR
Segment Routing
Segment Routing, RSVP-TE Enable SDN 2.0
Edge Intelligence, Stateless CORE

Segment Routing Introduction
Source Based Routing
• Idea from Draft-Kompella( Label Block and Index)
• Network represented by Segment
– Adj, Nodal Segment(unique #, one segment)
– Segments act as topological sub-paths that can be combined
together to form the desired path.
– Source Routing: the source chooses a path and encodes it in the
packet header as an ordered list of segments
• Every Node Forwarding table only take care portion of network
– All nodal segment, SRGB(SR Global Block)
– Adj Segment, No neighbors Adj Segment, Local Significant
• CSPF for nodal Segment
– Calculate the OIF only,
– label keep same(64-5000 reserved)
draft-ietf-isis-segment-routing-extensions-xx
1
6
2
3
45
7
16
15
14
1311
12Two Adjs
Four Adjs
protocols { isis {
source-packet-routing { node-segment ipv4-index 11}}
SR Index 11
Kireeti Kompella

Segment Routing Architecture
Step1: Build SR Topology by IGP Ext Advertisement
1
6
2
3
45
7
16
15
14
1311
12
Nodes
Segment
1
6
2
3
45
7
Adjacency
Segment In Label
Out
Label
Out intf
100 100 Intf1
101 101 Intf1
… … …
111 111 Intf2
5001 Pop Intf1
5002 Pop Intf2
… … …
5004 Pop Intf2
Node
Segment Ids
Adjacency
Segment Ids
Every Node
Share same
Various
interfaces
7
11
12
1
6
2
Controller
1
Prefix SID

Segment Routing Architecture
Step2: Controller calculate/program Label stacks from Edge
1
6
2
3
45
7
16
15
14
1311
12
1
6
2
3
45
76
11
1
7
11
12
1
6
2
7
15
144
3
5
3
4 14
5001
5007
5004
5014
PayLoad
5002
5007
5005
5016
PayLoad
Controller
2

Adj/Nodal Segment forwarding
Nodal/Adj Label space is different, No Recursive look up.
5001
5007
5004
5014
PayLoad
11
6
1
3
4
7
14
5007
5004
5014
PayLoad
5004
5014
PayLoad
5014
PayLoad
114
PayLoad
114
PayLoad
114
PayLoad PayLoad
• Node Advertise Adj label, IGP extension
• Only install Adj label on router, not aware of rest network.
• Push multiple labels stack to reach remote router
• POP label only
• Node advertise, unique {64-5000}
• IGP extension, normal SPF for all loopback
• Nodal label keep same in every nodes
• Swap Label Only
Packet injected anywhere
with label 114 will reach node 14
7
11
6
1
3
4 14

Path Creation
Source Based Routing
• A. Follow the IGP
– one label pushed, the nodal segment(Node-SID),
– SPF can leverage the ECMP path
– Example, {114}
• B. Explicit Via nodal ( like loose node in RSVP-TE)
– Push list of via nodal…
– Between nodal, SPF load balance.
– Easy to expended across Area/AS
– Example, {112,114}
• C. Explicit via Adj, any path
– Push of list of Via Adj
– Example, {5001,5002,5003,5004,114}
• D. Mixed Path with Adj/Nodal
1
6
2
3
45
7
16
15
14
1311
12
1
6
2
3
45
7
16
15
14
1311
12

ANYCAST SEGMENT ID FOR NODE REDUNDANCY
draft-psarkar-spring-mpls-anycast-segments-01
5100
8070
PAYLOAD
R3, SID: 80
[8000-9000]
Anycast SID: 100
R1, SID: 20
[5000-6000]
A1, SID: 30
[8000-9000]
A2, SID: 40
[8000-9000]
A3, SID: 50
[8000-9000]
A4, SID: 60
[8000-9000]
R2, SID: 70
[8000-9000]
D, SID: 80
[8000-9000]
S, SID: 10
[8000-9000]
5100
8070
8070
• Anycast SID
– A group of Nodes share the same SID
– Work as a “Single” router, single Label
• Any Topology
– Hub/Spoke
– Ring Topology
– Anycast and other nodes follow IGP
• Application
– ABR Protection
– Seamless MPLS
– ASBR inter-AS protection

TI-FRR/TI-LFA
SEGMENT ROUTING CAN GUARANTEE 100%
• IP-based FRR not guaranteed in any topology
• Directed LFA (DLFA) is guaranteed when metrics
only cover few cases, extra computation (RLFA)
also 90%+ topology
• TI-FRR, Target LDP session with RSVP Tunnel
• TI-LFA Segment Routing, 2 actions
– node segment to P node( From E1, can reach C1
without via failure link.
– adjacency segment from P to Q Node(From Q
node can reach C1 without via failure Link)
– TI-LFA 100% Guarantee
Backbone
100
Node SID to P node,
Follow Adj SID to Q
C1 C2
E1 E4
E2 E3
Segment Routing FRRIP FRR
Backbone
C1 C2
E1 E4
E2 E3
141 99
141 X
141
Target LDP
session
E LO O P -FR E E A LTE R N ATE S (R LFA )
N D TA R G E TE D LD P S E S S IO N S
600
incoming T-LDP sessions
0
10
20
30
40
50
60
70
80
90
100
Node protection for remote LFA vs. local LFA only
Remote LFA Local LFA
LFA R-LFA TI-LFA

Binding SID in Multi-Area SR, Larger network w/ Label stacks
Advertising LSPs from other protocols into SPRING
RSVP
SPRING
R20 R33
R34 R31
R21
Global node label = 120
RSVP LSP to reach R31 with
ERO=R33,R34,R31 (use local label 500)
RSVP LSP
120
500
Pay
Load
SR LSP
SPRING
200
510
Pay
Load
Global node label = 200
SR-LSP to reach R30 with
ERO=R32,R31,R30 (use local label
510)
R30
R32
332
331
330
Pay
Load

SRV6 STANDARDIZATION
• IETF is in the process of standardizing SRv6
– Draft-ietf-6man-segment-routing-header-01
– Work in Progress
• Two modes of operation
– Insertion mode
 SR ingress router inserts an SRH between IPv6 header and IPv6 payload
 SR egress router optionally removes the SRH
– Prepending mode
 SR ingress router prepends a new IPv6 header and an SRH to the original IPv6 header
 SR egress router always removes the new IPv6 header and the SRH, leaving only the original IPv6 header

Segment Routing IPv6(Animated)
include a SRH, Insertion mode and Prepending mode
Source
2001:db8:0:1::1
IPv6
Router
IPv6
Router
SRv6 Ingress
2001:db8:0:1::2
SRv6 Egress
2001:db8:0:1::5
SRv6 Router
2001:db8:0:1::3
Destination
2001:db8:0:1::6
255
Destination Address
Source Address
Hop LimitNext HDRLength
DSCP Flow LabelVer IPv6
HEADER
2001:db8:0:1::1
Segment
Routing Header
TCP Header
HDR Type
56
Length
TCP
Next HDR
4
Seg Left
C = 1
FlagsFirst Seg
Segment 0
Reserved
Segment 1
Segment 2
2001:db8:0:1::6
2001:db8:0:1::5
2001:db8:0:1::4
TCP Header
2542532522512502498080136136
2001:db8:0:1::62001:db8:0:1::32001:db8:0:1::42001:db8:0:1::4
SRHTCPSRHTCP
SRv6 Router
2001:db8:0:1::4
2001:db8:0:1::52001:db8:0:1::6
2
3221
Draft-ietf-6man-segment-routing-header-01

SEGMENT ROUTING SDN
WORK GREAT WITH SDN &PCEP
Tunnel onto
{11, 1, 3, 14}
• The network is simple, highly programmable and responsive to rapid changes
• Source Based routing, label pushed in the source will decide the path.
• On router, PCE Client no need signaling protocol to create path, Just Segment Routing.
• Better than PCE+RSVP-TE, No on-demand signaling the path.
• Better than Static MPLS label push from SDN, SR still have ECMP, Resilience, FRR.
11
6
1
3
4
7
14101
103
114
PayLoad
103
114
PayLoad
114
PayLoad
Path 11-1-7-3-14 is ok.
I account the BW.
Then I steer the traffic
on this path
Segment Routing
SDN Controller
Controller

Segment Routing vs LDP/RSVP
Keep the network Status Simple, Build the network topology
3
14
1311
Non Adj Prefix
Adj Prefix
Loopback
Adj Prefix
Loopback
1
6
2
3
45
7
16
15
14
1311
12
Segment Routing LDP • Segment Routing
– Only keep minimal status in network
– Keep all loopbacks
– With only adj prefix
– One SPF for all nodal ID.
• LDP
– Keep all Loopbacks
– Adj Prefix and non-adj prefix
• RSVP
– Keep all Loopbacks
– Potential full mesh LSP, and middle node
keeps a lot of transit information per LSP.
– Per LSP CSPF caculation
– Known as not so scale protocol.
5
1 2
12
6
4
7
16
15

Segment Routing vs MPLS
Features MPLS Segment Routing
Control Protocol
LDP/RSVP/BGP( any of label allocation) OSPF/ISIS,
BGP ( any of topology), SDN
OSPF or ISIS or BGP, or SDN Controller
Traffic Engineer RSVP, PCE Client, SDN OSPF/ISIS(option) SDN (option)
Fast Reroute LDP FRR, or RSVP-TE FRR Build in FRR, cover for all scenario
Inter-Area/Inter-AS
With help of BGP label, or RSVP-TE inter Area
hard to protect
Loose Node ID extension
Source Path Routing No, IGP only Yes, explicit indicate ingress
Scalabilities LDP same as IGP….RSVP limited. Node + ADJ Segment(less entry) Best Scale
Performance
Measurement
NO Build in with RFC 6374
SDN integration PCE, RSVP-TE PCE, BGP-LU, SR

SEGMENT ROUTING FOR CLOUD DEPLOYMENT
UNDERLAY PATH BY SR PROTOCOL, OVERLAY SDN CONTROLLER WITH LABEL APP
Virtual
Network
BMS
Segment List
FWLB
Virtual
Network
Containers
DevOps
Ops
App Build & Pkg
App Test & Deploy
Monitoring &
Analytics
Network Services
Automated
Provisioning
Monitoring &
Troubleshooting
Underlay Set-up
Orchestrator /
Controller / Tools
APP
Overlay Virtualized
Underlay Physical
label for
App/Dockers
or VPN etc.
Segment
List for
Path
vRouter

SPRING : DOMAIN APPLICABILITY
WAN
Metro
Data Center
Alternateway of doing FRR,
Nocorestate,BGP-LS to
export topology tocontroller
FRRin Metro rings, PW
transport
Fixed design, EBGP asIGP,
Simpler mgmt. with common
SRGB
Edge
Traffic engineering,
Northbound interface:PCEP,
BGP-LU, Flow-spec
WAN/Metro Core
Egress NodeIngress Node
Controller
Label stack topology

Controller
PCE WITH SEGMENT ROUTING
PCE-initiated LSP :
draft-ietf-pce-segment-routing-07
PCEP
PCC
PCCreate LSP
With SR-ERO
Delegate
PE1
1
Service
Request
2
3
5
4 LSP State report
w/ SR-RRO
PBR, QPPB
BGP Flow Spec
Open Flow
No Signaling
ASBR
BGP
• PCEP SR similar with RSVP-TE PCEP
– Open message negotiate SR-PCE-CAPABILITY TLV
– PCCreate LSP with SR-ERO for Label stack
– No Need Signaling on PE-P-PE
– LSP State report with SR-RRO
• BGP-LS get the network information
– TEDB information with label send back to Controller
– draft-gredler-idr-bgp-ls-segment-routing-ext-xx.txt
• Service mapping by
– Openflow/PBR/QPPB/BGP FlowSpec

BGP FlowSpec redirect to SR LSP Tunnel
Type Matching Type Matching
Type 1 Destination prefix Type 7 ICMP type
Type 2 Source prefix Type 8 ICMP code
Type 3 IP protocol Type 9 TCP flag
Type 4 Port (Defines a list of pairs that matches source or
destination UDP/TCP ports)
Type 10 Packet length
Type 5 Destination port Type 11 DSCP
Type 6 Source port Type 12 Fragment
Type Extended Community Encoding
0x8006 Traffic-rate 2 byte/4 byte float
0x8007 Traffic-Action bitmask
0x8008 Redirection 6-bye route-target
0x8009 Traffic-marking DSCP Value
NOTE: Detailed information about each type and filed can be found in RFC 5575 section#4 “Dissemination of Information”.

Segment Routing with PCEP and BGP-LS
 Prefix & node SID learning via ISIS &/or BGP-LS
 New PCEP capability, ERO subobject and TLVs
 draft-ietf-pce-segment-routing-06
 SPRING-TE LSP creation, visualization & optimization

Controller
BGP-LU WITH SEGMENT ROUTING
draft-rosen-idr-rfc3107bis-00.txt
NOT draft-ietf-idr-bgp-prefix-sid-03
BGP-LU
BGP-LU with
Label Stacks
PE1
1
Service
Request
2
ASBR
BGP
• BGP-LU Session between Controller/Router
– BGP LU carrier the label stack for SR/LSP
– BGP-LU carrier the Label stack for LSP + VPN Service
• BGP-LS get the network information
– TEDB information with label send back to Controller
– draft-gredler-idr-bgp-ls-segment-routing-ext-xx.txt
• BGP is the only protocol for Service and
Tunnel
– QPPB/BGP FlowSpec
– With additional Openflow/PBR
BGP-LU
101
103
114
80001
PayLoad
bespalov@CentOS-1 ~/exabgp-3.4.16/sbin>cat ~bespalov/config/exabgp neighbor 192.168.255.12 {
local-address 192.168.255.2;
peer-as 65000; local-as 65000;
family { ipv4 nlri-mpls; }
static {
route 10.255.255.8/32 {
next-hop 10.0.0.2;
label [ 800005 800007 800006 800008 ]; }}
Example from ExaBGP

• Overlays are widely used today
– South → North: Egress Peer Engineering (EPE)
– North → South: Load balancing, Floating IPs, ...
– East ↔ West: Multi Tenancy
• Currently overlays are IP-based, moving to MPLS
– Consistent end-to-end protocol; avoid ‘impedance-mismatch’ at boundaries
– Hierarchical Forwarding [MPLS Label Stack]; reduces FIB state
• Use SPRING-like approach
– Label stacking (hierarchy) to reduce FIB size on switches with merchant silicon
– Label stacking for ‘source-routing’ across WAN
– Different control plane inside data-center: BGP instead of IGP
MPLS IN DATA CENTERS

SPRING INTRA DATA CENTER ROUTING
Controller
VMVM
BGP-LU + SPRING
Egress Server Label
Egress Server Prefix-SID
SRGB
Proprietary
Egress VM Label
BGP-LU + SPRING
Egress TOR Label
Egress TOR Prefix-SID
SRGB
Proprietary
Egress VM +
Egress Server +
Egress TOR
Label stack
Payload
MPLS label
Egress VM
MPLS label
Egress server
MPLS label
Egress TOR
1

SPRING INTRA DATA CENTER ROUTING
VM
Egress TOR
Egress VM
Egress server
"Loose route"
ECMP over spine switchesECMP
Payload
MPLS label
Egress VM
MPLS label
Egress server
MPLS label
Egress TOR
1

BGP-LU PREFIX SEGMENT PROPOSAL
B C D E FA
VM
G
Controller
X
FEC: G
Label: 300
X
FEC: G
Label stack:
300, 1001,
4005(top)
Juniper Proposal [draft-gredler-idr-bgplu-prefix-sid-00]
BGP-LU
FEC: F
Label: 1001
BGP-LU
FEC: E
Label: null
SID: 5
SRGB:6000-
7000
BGP-LU
FEC: E
Label: 1005
SID: 5
SRGB:1000-
2000
BGP-LU
FEC: E
Label: 4005
SID: 5
SRGB:4000-
5000
300, 1001,
4005(top)
300, 1001,
1005(top)
300,
1001(top)
300(top)
VM

SPRING INTER DATA CENTER ROUTING
Payload
MPLS label
DC2 Egress VM
MPLS label
DC2 Egress server
MPLS label
DC2 Egress TOR
ECMP
DC1
Egress
Router
VM
MPLS label stack
DCI path: A, B, C, D
MPLS label
DC1 Egress Router
A
B
C D
DC2
Egress
TOR
DC2
Egress
Server
DC2
Egress
VM
DC2DC1
DCI
1
= Anycast Group

SPRING INTER-DOMAIN CLOUD TRAFFIC ENGINEER
CDNSP DC
Easy to optimize End-To-End Traffic for SP Owned Network.
How to optimize VIP Customer for Internet/Cloud connection?
1 Cloud Traffic engineer
2 Fish Topology
CDN
BRANCH
HQMOBILE
HOME
2

How to Select Which Peer to send
 Controller/RR may morning the BGP Peer Link
 Controller/RR find a tunnel from Ingress to ASBR
 Controller/RR based on certain rules to select ASBR
BGP EPE DESIGN PHILOSOPHY
Peer
Peer
Peer
Peer
BGP-LU w/ Label 100
IP Forwarding
Controller
GRE
LDP
Segment
Routing
BGP
LU 100
MPLS
LU Label
100
MPLS Label
Payload
Push
Push
Payload Payload
POP
LU Label
100
How ASBR identify a Peer
 Per Peer /32 address per label
 Install the MPLS Label POP for every Peer
 When ASBR received different label and
send traffic to specific Peer
How Ingress mapping traffic to ASBR/Peer
 Ingress push tunnel label to ASBR
 Ingress push BGP-LU label
2

BGP-LU EPE & MPLS KEY BENEFITS
EXTEND HOLLOW CORE/LSR TO PEERING, CHEAPER PEERING SOLUTION
TOR/BNG/PE
LU Label
SR Label
PayloadPayload
LU Label
SR Label
Payload
LU Label
Payload Payload
LSR
Core
Push
Push
SWAP POP
POP
NO IP Lookup!
Can be
Normal IP forwarding!
<128K Prefixes
MPLS LSRMPLS LER IP Forwarding
Netconf/Yang
MP-BGP EVPN
BGP LU/LS
Segment RoutingController
BRANCH
HQMOBILE
HOME
2

SEGMENT ROUTING AND EPE USE CASE
Data Center
Server
Content Provider Data Center
Content Provider
WAN
Peer
Peer
Peer
Controller
Tunnel encapsulationMeta-dataCustomer packet
Select Egress RouterSelect Peer
TOR Leaf Spine
VM
Tunnel encapsulationMeta-dataCustomer packet
Select ServerSelect VMFloating IP for service
2

SEGMENT ROUTING IN ACCESS/AGGREGATION
SIMPLIFIED BOX FUNCTION, MOVE INTELLIGENCE TO CONTROLLER
BGP-TE/SR
EVPN
BGP FlowSpec
Openflow
Controller
BGP-
3107
EVPN
VPWS
VPLS
6vPE IPv4 VPN
IPv4
IPv6
LDP
MPLS Forwarding
RSVPOSPF StaticIS-ISBGP-LU
TransportService
MPLS
Forwarding
SR/IS-IS
BGP
Minimal Protocols, Dumb Box in Access
• Keep OAM/Clocking
• No need Peer with others, only Controller
• No Need Compute, Controller got full network view.
3

SEAMLESS MPLS EVOLUTION – SEGMENT ROUTING
• Architect Change
– To manage 1,000+ boxes Add SDN
Controller
– RSVP-TE w/ RFC3107 to Segment
Routing
• Technical Benefits
– SP Fabric management with ZTP
– Better FRR with LFA/RLFA/TI-LFA
– Better ABR Node protection with
Segment Routing Anycast SID
– Better tunnel provision by BGP-LU or
Controller
– Better Tunnel Stitching by SR, no need
RFC3107, save one label
– Service Provision by NETCONF
– Network information collect by BGP-LS
Access MetroMobile Terminals
Branch
Office
Home
or SOHO
HQ
Service Edge
Router
Service Edge
Router
Agg
Agg
DC
NETCONF
for VPN Service
vBNG vEPC
Controller
leaf
leaf
leaf
leaf
BG—LU
for Tunnel
BGP-LS
for Infor
3

SEGMENT ROUTING FOR NFV SERVICE CHAINING
NO NEED NETWORK SERVICE HEADER(NSH), VNF SUPPORT MPLS
Services provided off-path by physical or virtual service nodes
Packets diverted through tunnels
 Return to forwarding path
 By tunnel
 Via forwarding
 After attention by other service nodes
Shortest path
Tunnel
Forwarding path
4

SEGMENT ROUTING FOR NFV SERVICE CHAINING
NO NEED NETWORK SERVICE HEADER(NSH), VNF SUPPORT MPLS
Push label Stack for Service Chaining.
VNF support MPLS label
Shortest path
Tunnel
Forwarding path
4
X
S1
S2
Y
Pay
Load
X S1
S2
Y
Pay
Load
S2
Y
Pay
Load Y
Pay
Load
Pay
Load

Openstack
Neutron & Neutron Extensions,
etc.
IP or MPLS
Transports
BGP
L3VPN,
BGP
EVPN
MPLS,
VXLAN
Service
Overlays
1. Physical distribution providing
fungible cloud resources close to
Telco consumer and business
eyeballs.
2. Enables applications to have:
1. Low Latency
2. High Availability (through
distribution)
3. High volume of last mile
throughput; minimizing network
wide capacity growth (choke points)
3. Seamless Integration of DC and
WAN technologies leveraging
existing network and operational
procedures.
Key Properties
~50-250
~250-1000
> 1000
Connectivity
Building Blocks
WAN/METRO
BGP (Control Plane)
MPLS (Service)
MPLS (Transport)
DC Fabric
BGP / OSPF (Control Plane)
IP (Transport)
+
DC Overlays
MPLS, VXLAN, IP, GRE, etc.
+
Telco Cloud
WAN METRO
METRO
WAN
WAN
WAN
WAN
WAN
WAN
METRO
WAN
TELCO CLOUD
WHAT IS THE TELCO CLOUD ARCHITECTURE? HIGH LEVEL ARCHITECTURE 5

TELCO CLOUD HIGH LEVEL REQUIREMENTS 10K FEET
Metro
D2F
OSPF-SR RSVP-TE OSPF-SR
Core Metro
Fabric
BGP-SRA
L
P
L
P
L
P
L
P
L
P
L
P
L
Fabric
BGP-SRA
L
P
L
Fabric
BGP-SRA
L
P
L
Fabric
BGP-SRP
L
A
L
Fabric
BGP-SRP
L
A
L
Fabric
BGP-SRP
L
A
L
P
L
3107 3107
C
L
C
L
C
L
EVPN
• EVPN Signaling is a key requirement for *all* control
plane signaling
• EVPN-VPWS with flexible-cross-connect for all L2
pseudowires
• EVPN-MPLS multi-point with IRB
• EVPN-VXLAN for for IP fabrics
SR
• Underlay transport is based on Segment Routing
• No IGP in Telco Cloud. Only BGP-LU with prefix-SID
extensions
• Metro moves to OSPF-SR
MPLS in SP Fabrics - High level vision
5

STATIC SEGMENT ROUTING
Step1:Buildthe SegmentRoutingTopology,SingleHopLSP
JET w/
SPRING
Adj_sid_21:
In_label =
10100003
Pop
Nexthop = R1
Adj_sid_32:
In_label =
10100002
Pop
Nexthop = R2
Lsp_41:
In_label = 10100001
Swap
Out_labels = 10100003, 10100002
Nexthop = R3
R1 R2 R3 R4 R5CE1 CE2
6
Adj_sid_23:
in_label =1000001
Pop
Nexthop = R3
Adj_sid_34:
in_label =1000002
Pop
Nexthop = R4
Adj_sid_45:
in_label =1000003
Pop
Nexthop = R5

STATIC SEGMENT ROUTING
Step2:PushtheSRLSPfromEdge
JET w/
SPRING
Adj_sid_23:
in_label
=1000001
Pop
Nexthop = R3
Adj_sid_21:
In_label =
10100003
Pop
Nexthop = R1
Adj_sid_34:
in_label =1000002
Pop
Nexthop = R4
Adj_sid_32:
In_label =
10100002
Pop
Nexthop = R2
Adj_sid_45:
in_label =1000003
Pop
Nexthop = R5
Lsp_41:
In_label = 10100001
Swap
Out_labels = 10100003, 10100002
Nexthop = R3
Lsp_51:
Dest = R1
Push
Out_label =
10100001
Nexthop = R4
Lsp_15:
Dest = R5
Push
Out_labels = 10000003, 10000002, 10000001
Nexthop = R2
R1 R2 R3 R4 R5CE1 CE2
Ingress LSP with a stack of Adj-SID labels:
destJnxP = IpAddressAddrFormat("128.9.148.133")
dest = JnxBaseIpAddress(destJnxP)
lsp = RoutingStaticLspEntry()
lsp.name = “lsp_15”
lsp.type = 0 << ingress
lsp.Prefix = StaticLspEntryPrefix()
lsp.Prefix.destination = dest
lsp.label_operation = 0 << push
lsp.outgoing_labels = ["1000003","1000002","1000001"]
lsp.nexthop = "55.1.12.2"
lsp.preference = "6"
lsp.metric = "1"
addReq = RoutingStaticLspAddRequest(lsp)
addReply = staticLsp.StaticLspAdd(addReq)
print 'Reply status = ', addReply.status
6

OPENFLOW WITH SEGMENT ROUTING
ONF'sSPRING-OPEN
• OpenFlow 1.3.4 can push 2 labels
– Service label and Tunnel labels
– Use Openflow group Chain to push multiple labels
• Openflow Build the Segment Routing Topo
– Adj SID for POP
– Node SID for continue(no change/no swap)
• No RSVP-TE/LDP and IGP on those routers
– Only MPLS dataplane and Static configure from Openflow
• A lot of limitations BUT can show
– Intelligence on Controller, very ugly CLI on Controller
– White Label box with simple MPLS forwarding Plane
– Demo in Dec 2014. https://goo.gl/ddeX5N

Summary- Segment Routing Re-Invent MPLS
• Seamless work with SDN, BGP-LU/PCE-P Architecture.
instantly tunnel setup. for next generation Application
driven networks
• Work with NFV, such as Service Chaining
• Simplified MPLS Control Plane, OSPF/ISIS only. No need
Signaling for tunnel setup. Tunnel path decided by
ingress router.
– source routing and hence explicit routing
• less status inside network
element(router/switch)Topology based on Adj/Nodal
information. Independent with Application Status
• 100% IP fast reroute protection, Fit for any topology
• Work great with Traffic Engineer and IPv6.. With QoS,
OAM/SLA
Segment
Routing
SDN
BGP-LU
PCEP
100% FRR
MPLS
Forwarding
Service
Chaining

Segment Routing Customers
Re-invent MPLS again!Foundation of NFV/SDN
• Major vendors claim to support, ALU/Cisco/Huawei/Juniper
• Known customer transforming to SPRING
• AT&T CORD
• Microsoft SWAN
• China OTT, Tencent/Alibaba
• Japan Softbank/NTT
• ANZ Telstra etc
DCCPE Access Edge Core
NFV
Underlay
SDN

ROAD TO SELF DRIVEN NETWORK
SDN/NFV
Controller
Network
Telemetry
Segment Routing
Network

SUMMARY
1
2
3
4
5
Segment Routing simplify Protocols
Segment Routing enable better traffic engineer, IGP/BGP, Egress Peering Engineering
Segment Routing Provide better FRR protection
Segment Routing can be deployed in All Domains, DC, Metro, Access, Telco Cloud etc.
Segment Routing Design for SDN

JUNIPER CONFIDENTIAL
THANK YOU

WAN SDN meet Segment Routing

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