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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
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DWDM GMPLS Deployment ExperienceJoint 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
IETF GMPLS applied to DTN • DTN supports the functions of IETF GMPLS RFCs (e.g., 3471) as they apply to Lambda (10G) or Digital Wrapper (2.5G) LSPs and Lambda- and Sub-Lambda- Switch Capable Interfaces • In-fiber (OSC) control channel Lambda / Digital Wrapper LSP Infinera Network Amp DTN Each of these (line-side) DTN interfaces is Lambda and Sub-Lambda Switch Capable
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
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
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
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 I-D stage
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
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
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)
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
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
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 • Customer Network Manager provides customer network partitioned views • Secure Web-based access to customer data • Circuits & endpoints • Fault data: alarms • Performance Mgmt data Secure web-based access Cust B VPN View Cust A VPN View Customer Network Manager EMS Cust B Infinera GMPLS Powered Network Cust B Cust A Cust A Cust A
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): • Read-only CNM: display configuration, PM, alarms • Ability to provision, within limits • For example, changing the rate or payload but not the destination • Full flexibility to provision • Can be accomplished by management protocols or signaling/routing protocols (IETF GMPLS UNI / L1VPN, OIF OVPN)