MPLS/GMPLS for Next Generation
Optical and Carrier Ethernet Networks
Prakash Siva – Manager, Control Plane Group
psiva@turinnetworks.com

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Objectives for Carrying Ethernet
over a SONET/SDH Transport Network
Enable scalability for Ethernet Services over SONET/SDH
infrastructure
Provide fast reroute for Ethernet Service protection
Efficient bandwidth usage over SONET/SDH network
Enable TDM service to be carried in conjunction with thepacket based services
Simplify Service Operations versus provisioning a router
Provide “Point and Click, End to End” provisioning
Allow Carriers to build on SONET/SDH resiliency and provide
Carrier Ethernet Service SLAs with QoS
OAM – Optical + ethernet + MPLS

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GMPLS Background
Used by SONET/SDH MSPP to automate service provisioning
Each network element running GMPLS supports:
OSPF-TE routing
RSVP-TE signaling
Label distribution through RSVP

GMPLS is a partial superset of MPLS
Common traffic engineering (TE)Implicit vs. explicit labels
Bi-directional labels
Label sets, link bundling

Overlay, peer and hybrid models

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Turin GMPLS solutionDistributed, GMPLS based control plane
Neighbor discovery, topology discovery and distribution
OSPF based routing protocol with support for unnumberedinterfaces
Traffic engineering (OSPF-TE) and TE database
OSPF-TE extensions with opaque LSA (RFC 3630)
Per-area type 10 opaque LSA

Path computation on ingress node (CSPF)
Support for fully strict, loose, and partially constrained paths
1+1 path protection - node and link diverse paths

RSVP-TE (with support for hot-standby/redundancy)
Generalized, switch managed labels
Support for e2e low-order services
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Turin Networks Confidential – Do Not Distribute2Bridging the MPLS and GMPLS domain
Ethernet cards in MSPPs can be adapted to exchange thenecessary routing information to allow MPLS and GMPLS
domains to communicate
These Ethernet cards will be responsible for
Receiving and sending RSVP requests
Switching MPLS labels
Performing normal Ethernet (L2 switch) related operations

The adapted Ethernet cards are simply a client interface into
the existing GMPLS control plane
Use existing GMPLS control plane toEstablishing a forwarding adjacency (FA)
Exchanging IP routing information

The adapted Ethernet cards are simply a client interface intothe existing GMPLS control plane

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End to End Ethernet Service Provisioning

CE - Site A

CE - Site Z

Node 1

Ethernet (UNI)

Node 9P2P EVC

Ethernet (UNI)
Physical path ofEVC

User points and clicks at Nodes A to Z, and network setup theconnection
D-LSPs are routed & switched on the intelligent Ethernet card
G-LSPs continue to created on optical switching nodes
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MPLS over SONET/SDH migration
CoreEdge

Edge

LSRBladeA

LER

VLAN1

VLAN1LSPLSPIntroduce LSR functionality as the services grow
SONET/SDH partitioned to carry MPLS
Partitioning can be static or dynamic
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Data LSPs over Optical LSP
Egress LER

Ingress LER
FWD adjacency
Equivalent

ADM

ADM

ADM

Fwd - Adjacency TDM

te-LSP

8g LSP( LSP - TDM )Turin Networks Confidential – Do Not Distribute

4LER

B

LSPs Set up steps
EthSwitch

User requests EVC between UNI ports

EthSwitch

te-LSP (data lsp)

EoM
MapperMoS
Mapper

TimeFRR
ProtectedLSP

EoM
MapperMoSMapper

Bundled VCAT pipe + LCAS

g-LSP (optical LSPs)
VCG

1+1PathPG

1+1PathPG

VCG

1+1 path
protection

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Efficient Path Bandwidth Management
DynamicallyDynamically
Resizedg-LSP-54 withincreased BW

te-LSP-59

Resizedg-LSP-49 withincreased BW= ADM= LSR or LER
82= Optical Path (g-LSP)
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CE - Site A

CE - Site Z

9537

CE - Site B

Dynamic resizing of bandwidth for optimal sizing of service routes
te-LSP (blue) needs to route thru’ nodes 5 and 4Optical path g-LSP is dynamically resized

Use of VCAT/LCAS to allow hitless resizing
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5Pseudo-wire tunnel (PWE)
8426CE - Site A

CE - Site Z

195

7

3

Equivalent to
FA- PSC(te- LSP is a packetswitching FA)

LDP signaled
LSP (does not switchon 4)

842Site Z
6CE - Site A

CE -

1
95

LDP label

3PSN Tunnel Label

725

1

LDP label

25

Ethnernet
Packet11

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MP2MP service (VPLS)
CE - A3

CE - B1

48

LSPs for VPLS domain A(connects A1, A2, A3)

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CE - A1

CE - B3

1953

LSPs for VPLS domain B(connects B1, B2, B3)

7
CE - A2

CE - B2

Operation:
Full mesh of point to point LSPs
Support for customer port (untagged) or multiple VLANS with subscriber VLAN tags
Learning and forwarding based on MAC addresses, Flooding on per VSI-x basis
Loop free topology with split horizon (no forwarding from one VSI-x trunk port to anotherVSI-x trunk port)
Failure recovery based on FRR (RSVP-TE)
Membership discovery based on provisioned information from management plane

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6Protection schemes
No Protection
Optical protection
Ring based schemes (UPSR/2f-BLSR)
Mesh based (node/link diverse path)te-LSP protection
Path protection (source based)
Local protection with fast reroute (FRR)
Link failure
Node failure
1:1 protection
1:N protection

Failure detection and notification
Bi-directional failure detection (BFD) protocol
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Te-LSP based Path Protection
Workingdata LSP
4826

CE - Site ACE - Site Z

1953Protect
data LSP

7Source computes working and protect LSP paths
Resources can be reserved before failure (double booking)Fastest with pre-computation and pre-signaling
Detection at ingress may be slow, but allows complete QoS
control of secondary path
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1:1 Protection

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1:1 Protection
Segment of working LSP protected by a backup LSP
Point of local repair (PLR) and merge point (MP)Can protect against link failures
Backup link is called a ‘detour’
PLR calculates and signals detour path during primary path setup
resulting in creation of MPLS forwarding state ate PLR, MP andtransit nodes (3,5 in example)
PLR detects failure and swaps incoming label to that of the detourpath
MP understands relationship between working and protect paths
Increased state in MP/PLR
Support for working path QoS along protect path
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N:1 (facility protection)

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N:1 Protection
Every N working LSPs protected by a single LSPLabel stack
Based on label swap and insert of protect LSP label into label
stack at PLR
Can protect against node/link failures
No new forwarding state at MP
Penultimate-hop popping (PHP) on last transit node alongprotection path
BW protection
Interaction of FRR and path protection
Scalability – new LSPs, increased forwarding state

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Turin Networks Confidential – Do Not Distribute9Conclusion
Turin solution builds on existing GMPLS based control plane
Allows Ethernet switching layers to request optical tunnel
setup
Hitless addition/removal of optical BW using VCAT/LCAS
Selective upgrades to mesh network along spans that areheavily used
Allows TDM/Ethernet/MPLS switching to co-exist on the same
network element
MPLS encapsulation of Ethernet (EoMPLS) and pseudo-wires
Fast-reroute based protection of the RSVP tunnels
Enable an evolutionary change from TDM to packet switched
networks (pay as you grow)
Unified control plane model leverages the best of TDM/packet
worlds to provide optimal solutions
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Questions ?

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