1 TM8106 Optical Networking Multi-Protocol Label Switching-Transport Profile (MPLS-TP) By Ameen Chilwan Syllabus: [1] MPLS Transport Profile (MPLS-TP): A Set of Enhancements to the Rich MPLS Toolkit, Juniper Networks, Whitepaper, [2] Dieter Beller, Rolf Sperber, MPLS-TP – The New Technology for Packet Transport Networks, 2 nd DFN Forum, 2009.

2 Outline Transport Networks MPLS-TP Basics Standardization History MPLS-TP Components  OAM  Control Plane  Resiliency Synchronization Physical Infrastructure Support Deployment Options Misconceptions about MPLS-TP Conclusion TM8106 Optical Networking - MPLS-TP

3 Transport Networks Goal of transport network Requirements TM8106 Optical Networking - MPLS-TP

4 Packet-based Transport Network MPLS has been serving as one for almost a decade  Connection-oriented and Packet-based  Designed to carry L3 IP Traffic  Establishes IP traffic paths  Associates these paths with arbitrarily assigned labels GMPLS extends MPLS  Label switching for TDM (SONET/SDH) Wavelength (λ) Spatial switching (incoming ports to outgoing ports) TM8106 Optical Networking - MPLS-TP

5 MPLS-TP Emergence Lacks some features of SDH-like networks  Operation, Admin and Management (OAM)  Resiliency  Scalable operations  High availability  Performance monitoring  Multi-domain support IETF and ITU-T joined forces to enhance MPLS  MPLS-TP TM8106 Optical Networking - MPLS-TP

6 MPLS-TP Background Drivers for MPLS-TP  Rise in demand for service sophistication Bandwidth-hungry services  Pressure to reduce operational cost (OPEX)  Maximize the value per bit Lead to a technology that is almost SDH-like  Carrier-grade  Packet-switched  With OAM features TM8106 Optical Networking - MPLS-TP

7 MPLS-TP Overview Takes a subset of MPLS/GMPLS Enhance with some functionalities  Network Management (e.g. FCAPS)  Dynamic provisioning of transport paths via control plane  Provide restoration functions  E2E path provisioning across networks/domains Characteristics  Connection oriented  Client and physical layer agnostic  OAM similar to SDH-like networks  Protection schemes  Network provisioning via centralized NMS  GMPLS Control plane applicable TM8106 Optical Networking - MPLS-TP

8 Standardization History ITU-T will define requirements IETF will work on protocol extensions TM8106 Optical Networking - MPLS-TP

9 MPLS-TP Components TM8106 Optical Networking - MPLS-TP

10 Operation, Admin and Management Dedicated OAM packet  interspersed into the associated user traffic flows  Created and processed by maintenance end-points  Intermediate points can also process them & collect data OAM Tools TM8106 Optical Networking - MPLS-TP

11 OAM Functions and Tools Functions  Fault Detection (e.g. connectivity check)  Fault Localization (e.g. loopback, lock)  Performance Monitoring (e.g. delay, loss) Tools (Existing MPLS tools extended)  Bidirectional Forwarding Detection (BFD)  LSP Ping  LSP Trace TM8106 Optical Networking - MPLS-TP

12 OAM Enhancements TM8106 Optical Networking - MPLS-TP

13 Associated Channel (ACh) MPLS-TP shall work without IP functionality  MPLS uses Ach for framing, forwarding and encapsulation  Enhanced by GACh and GACh Label (GAL)  Support in-band control channels GACh  Ensure congruency between OAM packets and data path  Indicates tagged packet must be processed by special function  Not suitable for static provisioning Because negotiated when pseudowire was setup Solved using GAL (reserved value of 13) –Enables easy extraction at end- and mid-point nodes TM8106 Optical Networking - MPLS-TP

14 Control Plane (Static and Dynamic) Responsible for setup of LSP MPLS has mature and dynamic control plane  OSPF-TE, IS-IS-TE, RSVP-TE and BGP Current transport networks have static control plane  using NMS MPLS-TP  Can have both static or dynamic  Dynamic has advantages like: Scaling Advanced protection functions (e.g. LSP tail-end protection) Restoration  Distributed control plane Signaling, routing and TE  Decoupled from data plane TM8106 Optical Networking - MPLS-TP

15 MPLS-TP Control Plane (contd…) TM8106 Optical Networking - MPLS-TP

16 Resiliency Mechanisms in MPLS  LSP fast reroute  Pseudowire redundancy  Path protection Enhancements in MPLS-TP  OAM-triggered protection  Optimizing protection in ring topologies Circuit networks are interconnected rings Fast reroute works but inefficient Wrapping and steering implemented in MPLS-TP TM8106 Optical Networking - MPLS-TP

17 Synchronization Approaches  An overlay synchronization network Requires parallel network  Distributed reference clock Reference clock at least at the edges  Forwarding of clock information across packet domain Synchronization protocol TM8106 Optical Networking - MPLS-TP

18 Synchronization (contd..) Packet based clock recover solution  Adaptive Timing Encapsulated and de-capsulated at packet edge nodes between TDM and packet domain  Differential Timing Both edge nodes performing inter- working have access to reference clock TM8106 Optical Networking - MPLS-TP

19 Physical Infrastructure Support MPLS-TP over SDH/SONET, PDH and OTN  ITU-T defines Generic Framing Procedure (GFP) Encapsulate variable length payload of various client signal Contains User Payload Identifier (UPI) MPLS-TP uses same UPI point code as MPLS OTN includes WDM network layer for transport of a variety of OTN client signals SONET/SDH uses virtual concatenation to form transmission pipelines with larger capacities MPLS-TP over Gigabit Ethernet Two-octet long Ether Type field in Ethernet II Indicates which protocol is encapsulated in payload TM8106 Optical Networking - MPLS-TP

20 Deployment Options Access and aggregation network  Major migration from circuit to packet happening nowadays OAM enhancements will allow more visibility into Core TM8106 Optical Networking - MPLS-TP

21 Misconceptions about MPLS-TP MPLS-TP is a new technology, not part of MPLS  It is a subset of MPLS with some enhancements Extensions in MPLS-TP are not applicable in MPLS  Actually meant to apply in MPLS to make it broadly applicable MPLS-TP requires substantial changes in MPLS  Design goal of MPLS-TP is to keep MPLS architecture MPLS-TP require static provisioning  Supports both static and dynamic control planes Requires forklift hardware upgrades  Might be true for some vendors, but not always, not in Juniper at least TM8106 Optical Networking - MPLS-TP

22 Conclusion MPLS-TP is  Subset of MPLS/GMPLS  Enhancements esp. OAM Fault management Performance monitoring  E2E integration with existing and next generation MPLS networks MPLS-TP intended to  Tie together service routing transport platforms  Advantages of tying together Consistent operations and OAM functions across networks Seamless interworking with IP/MPLS networks Scalability due to multiplexing capability Supports huge variety of services encapsulated into pseudowires TM8106 Optical Networking - MPLS-TP

TM8106 Optical Networking - MPLS-TP