Download 20070716-frank

DWDM GMPLS Deployment Experience
Joint Tech Workshop July 2007
George Frank, Ph.D.
Infinera
Infinera DTN: DWDM combined with Digital
Switching
 DWDM transport system that
employs photonic integrated circuits
(PICs)
 OEO / Digital Processing
 2.5Gb-granular switching
 Proprietary framing, similar (but not
equal) to G.709
Digital Monitoring (FEC, client payload)

 Dynamic switching capability +
ability to support mesh topologies 
appropriate for GMPLS use
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IETF GMPLS applied to DTN
Lambda / Digital Wrapper LSP
Infinera Network
Amp
DTN
Each of these (line-side) DTN
interfaces is Lambda and SubLambda Switch Capable
 DTN supports the functions of IETF GMPLS RFCs (e.g., 3471) as they
apply to Lambda (10G) or Digital Wrapper (2.5G) LSPs and Lambdaand Sub-Lambda- Switch Capable Interfaces
 In-fiber (OSC) control channel
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DTN GMPLS Functions
 Topology / Neighbor / TE Discovery and Distribution
 Automated Optical Power/Gain Control
 LSP setup & release
 CSPF path computation with explicit routing
 Diverse path computation
 LSP recovery (restoration)
 Service Level Management
 (Sub-)Network-wide Alarms & Admin State
 Regroom (Bridge & Roll) with minimal traffic disruption
 UNI
in general mesh topologies
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Key IETF GMPLS Standards
Compliance
Supported internal to a
DTN network, where
applicable to a Lambda
Switch Capable (LSC)
transport network
Specification
IETF RFC 3473, GMPLS Signaling: RSVP-TE: Extensions
IETF RFC 3471, Generalized MPLS - Signaling Functional Description
IETF RFC 3209, RSVP-TE: Extensions to RSVP for LSP Tunnels
IETF RFC 2205, Resource ReSerVation Protocol (RSVP) – Version 1 Functional Specification
IETF RFC 3477, Signalling Unnumbered Links in RSVP-TE
IETF RFC 2961, RSVP Refresh Overhead Reduction Extensions
IETF RFC 4203, OSPF Extensions in Support of Generalized MPLS
IETF RFC 4202, Routing Extensions in Support of Generalized MPLS
IETF RFC 3630, Traffic Engineering Extensions to OSPFv2
draft-ietf-gmpls-recovery-e2e-signaling-03.txt (now RFC 4872), RSVP-TE Extensions in support of End-toEnd GMPLS-based Recovery
draft-ietf-gmpls-recovery-terminology-05.txt, Recovery Terminology for GMPLS
draft-ietf-l1vpn-ospf-auto-discovery-02.txt, OSPF Based L1VPN Auto-Discovery
Interop Supported w) 3rd
party
IETF RFC 4208, GMPLS UNI: RSVP-TE Support for the Overlay Model
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Advantages of Transport Network Intelligence /
Control Plane
 Network-is-master model (which ensures data
integrity)
 Automated topology discovery & circuit provisioning
 Ease of Test & Turn Up
 Extends Point & Click circuit provisioning
 Automated restoration capability
All of these can result in a reduction of operating &
maintenance costs
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Deployment Challenges: Scaling
 Deployed in several long-haul and regional mesh
networks, each with 100+ DTNs
 At some point, a single flat GMPLS domain reaches a
node count upper limit. When it’s too large:
 Route convergence or establishment of neighbor adjacency


takes too long, or doesn’t stabilize
Control/Mgt-plane initialization takes too long
Thus Operations degrade
 Several ways to deal with this:
 Increase processing power & memory
 Make code more efficient
 Use multiple domains or areas and inter-domain /
hierarchical techniques
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Deployment Challenges: Scaling
 Decisions or issues involving the use of multiple
domains:
 Recovery mechanisms must address border node failures
 Nested, stitched, or contiguous LSPs
 Path (re-)optimization: end-to-end vs. per-domain
 Distributed in NEs, or use PCE (centralized or distributed)
 Confidentiality issues between network operators
 Per-domain or backward recursive
 Global Concurrent Optimization
 IETF multi-domain framework & requirement RFCs
already exist. Some specific protocols or protocol
extensions (e.g., PCEP, RSVP-TE, OSPF-TE) are in ID stage
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DTN GMPLS-Based Recovery Support
 End-to-end recovery: the originating DTN detects a
datapath fault, tears down the LSP, and re-establishes
a new one avoiding the fault
 Initial DTN releases & deployments: this is used
primarily on transport paths that are already protected
(to tight Availability SLA quality) at higher layers such
as IP/MPLS or SONET/SDH
 For operator convenience, to avoid manually establishing a
new path
For resiliency to multiple faults

 More work is needed to achieve tight (e.g., 50 ms)
Availability SLAs
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Deployment Challenges
 Simplifying Operations
 Add minimally-disruptive reversion, both manual and

automatic: use bridge&roll (make before break) techniques
Supplement with Network Planning: Automated Failure
Analysis
 Reducing Recovery Times & Scaling
 Improve code efficiency
 Pre-configure or pre-compute restoration paths
 Perhaps pre-signal as well
 Localize the procedure: use GMPLS segment recovery
 Use inband overhead to rapidly signal fault location
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New Service Opportunities: UNI & L1VPN
 Extends Transport Network Intelligence across a larger
domain: extends
 Network-is-master model (data integrity)
 Automated topology discovery & circuit provisioning
 Automated restoration capability
to a multi-vendor, and potentially much larger, network.
Further reduction of operations costs
 Facilitates new applications & services:
 L1VPN
 Dynamic IP load balancing between routers
 Multiple circuits to time-share same bandwidth (“Time of day”
services)
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Reference Diagram for RFC 4208 GMPLS UNI:
RSVP-TE Support for the Overlay Model
edge nodes in one overlay network
Each of these (client-side) DTN
interfaces is currently Fiber
Switch Capable (FSC). In the
future, DTN will support TSC and
L2SC client interfaces
core nodes in one Infinera DTN core network
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UNI functions
 Setup & explicit teardown of bidirectional LSPs:



OC192/STM64, 10GbE LAN, OC48/STM16, GbE
 Transparent service
Out-of-band (Ethernet) IP Control Channel
A Switched Connection (SC) setup via UNI is treated
similarly to any other SPC (setup via GUI or TL-1). A few
minor differences
DTN core network automatically advertises (within the DTN
network only) reachable edge node addresses & port
identifiers
 Reachable address information is not passed over the UNI
Future:
 IETF peer model, ITU-T ASON E-NNI: advertise reachable
addresses and topology
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L1VPN
 Partitioned transport networks for
supporting multiple virtual transport
networks on a shared physical
network
 Applications:
 Multi-layer TE optimization
 Administration sub-domains
 Customer L1VPN
Secure web-based
access
Cust B
VPN View
Customer Network Manager
 Customer Network Manager
provides customer network
partitioned views
 Secure Web-based access to
customer data
 Circuits & endpoints
 Fault data: alarms
 Performance Mgmt data
Cust A
VPN View
EMS
Cust B
Cust A
Infinera
GMPLS Powered
Network
Cust B
Cust A
Cust A
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L1VPN: Several Options & Levels
Options:
 Bandwidth packages: nx10G, 100G, and beyond
 Interface can be channelized or not
 Channelized interfaces allow finer-grained bandwidth
management
 GMPLS use is optional, for both provider and customer
Levels (of customer access to the provider network):
1. Read-only CNM: display configuration, PM, alarms
2. Ability to provision, within limits
 For example, changing the rate or payload but not the destination
3. Full flexibility to provision
 Can be accomplished by management protocols or signaling/routing
protocols (IETF GMPLS UNI / L1VPN, OIF OVPN)
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Thank You
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