MPLS-TP in Metro Transport Networks. Bringing Carrier Grade Performance to Data Services

MPLS-TP in Metro Transport Networks Bringing Carrier Grade Performance to Data Services

MPLS-TP in Metro Transport Networks - Bringing Carrier Grade Performance to Data Services December 2012 Copyright by ECI Telecom, 2012. All rights reserved worldwide. The information contained in the documentation and/or disk is proprietary and is subject to all relevant copyright, patent, and other laws protecting intellectual property, as well as any specific agreement protecting ECI Telecom's rights in the aforesaid information. Neither this document nor the information contained in the documentation and/or disk may be published, reproduced, copied, modified or disclosed to third parties, in whole or in part, without the express prior written permission of ECI Telecom. In addition, any use of this document, the documentation and/or the disk, or the information contained therein for any purposes other than those for which it was disclosed, is strictly forbidden. ALL RIGHTS NOT EXPRESSLY GRANTED ARE RESERVED BY ECI TELECOM. Any representation(s) in the documentation and/or disk concerning performance of ECI Telecom product(s) are for informational purposes only and are not warranties of product performance or otherwise, either express or implied. ECI Telecom's standard limited warranty, stated in its sales contract or order confirmation form, is the only warranty offered by ECI Telecom. The documentation and/or disk is provided AS IS and may contain flaws, omissions, or typesetting errors. No warranty is granted nor liability assumed in relation thereto, unless specifically undertaken in ECI Telecom's sales contract or order confirmation. Information contained in the documentation and in the disk is periodically updated, and changes will be incorporated in subsequent editions. If you have encountered an error, please notify ECI Telecom. All specifications are subject to change without prior notice.

CONTENTS Contents Introduction... 5 MPLS... 6 MPLS-TP: Transport-Optimized MPLS... 7 MPLS-TP Key Requirements... 8 Management... 8 OAM... 8 Data Plane... 8 Control Plane... 8 Protection... 9 MPLS vs. IP-MPLS... 10 ECI Support of MPLS-TP... 12 About ECI Telecom... 13 ECI Telecom Ltd. Proprietary iii

CONTENTS iv ECI Telecom Ltd. Proprietary

INTRODUCTION Introduction Multi-Protocol Label Switching Transport Profile (MPLS-TP) is a joint venture of the IETF and ITU-T aimed at defining a transport-optimized MPLS. In order to understand the need for this initiative, it is worth reviewing why MPLS evolved in the first place. MPLS was designed to overcome some of the native Ethernet drawbacks that became an obstacle for deployment when Ethernet expanded from the LAN, where it was originally used, into the WAN. In order to cut transport costs, attempts were made to use Ethernet not only as a service, but also as the transport layer. Some major obstacles were revealed: No guaranteed QoS Reliability no carrier-class protection schemes Scalability - number of services Complex operation and troubleshooting Lack of service OAM No legacy support Many of the drawbacks were linked directly to the connectionless nature of Ethernet, which cannot be overcome unless the networks are extremely overengineered. So, protocols and technologies defining Carrier Class Ethernet, were developed to overcome these drawbacks Carrying Ethernet over SDH was probably the first protocol, followed by Multi- Protocol Label Switching (MPLS), Provider Bridges (IEEE 802.1ad), Provider Backbone Bridging (IEEE 802.1ah), and Provider Backbone Bridging-Traffic Engineering (IEEE 802.1Qay). However, MPLS stood apart in the comprehensive way it addressed native Ethernet s performance weaknesses. ECI Telecom Ltd. Proprietary 5

MPLS MPLS Standardized by the IETF, MPLS is a scalable protocol-agnostic mechanism designed to carry both circuit and packet traffic over virtual circuits known as label switched paths (LSPs). Operating as a layer between the traditional definitions of Layer 2 and Layer 3, MPLS makes packet-forwarding decisions based on the contents of the label without examining the packet payload. MPLS addresses some of the key attributes as defined by MEF (Metro Ethernet Forum) for Carrier Ethernet: QoS - assures service delivery with the right quality: MPLS is a connection-oriented technology Traffic engineering and Connection Admission Control (CAC) Differentiated service various Classes of Service (CoS) are provided Reliability: < 50 msec Fast Reroute (FRR) for failed node or link Scalability: Number of elements and services One 20-bit MPLS tag supports 1M service for each node OAM: Some MPLS connection OAM mechanisms exist using IP technology MEF services: E-Line (P2P), E-LAN (MP2MP), E-Tree (P2MP) Legacy support: Allows encapsulation legacy services (ATM, Frame Relay, TDM) However, up until recently, MPLS encountered difficulties expanding beyond the network core towards the metro and access domains. This was for the following reasons: 1. The historical linkage between MPLS and IP switches/routers meant that service providers were reluctant to introduce these high-cost network elements on a large scale. This would have demanded a steep learning curve on metro network managers needing to adapt to IP configuration. 2. Service providers were reluctant to pay the cost associated with having control plane functionality distributed and integrated into each node across an MPLSbased network and they were also reluctant to let go of network control. The dynamic control-plane nature also introduced operation and maintenance complexity as well as network instability, another burden that operators were reluctant to accept. MPLS-TP has now come into play as an affordable MPLS, deployable everywhere. 6 ECI Telecom Ltd. Proprietary

MPLS-TP: TRANSPORT-OPTIMIZED MPLS MPLS-TP: Transport-Optimized MPLS As its name indicates, the new emerging MPLS-TP standard aims to define a feature list most relevant for metro transport networks, and to support packet transport services with a degree of predictability similar to that found in existing transport networks. One of the key elements is eliminating the cost and complexity associated with control plane functionality being distributed and integrated into each node across an MPLS-based network and replacing it with a more affordable transport-oriented static configuration through a transport-grade Network Management System (NMS). Carriers are considering migrating to packet transport networks in order to reduce their costs and to improve their ability to support services with guaranteed SLAs. Migrating from SONET/SDH to packet transport networks should not involve dramatic changes in network operation, should not necessitate extensive retraining, and should not require major changes to existing work practices. The aim is to preserve the look-and-feel to which carriers have become accustomed in deploying their SONET/SDH networks, while providing common, multi-layer operations, resiliency, control and management for packet, circuit, and lambda transport networks (MPLS-TP Requirements Draft). ECI Telecom Ltd. Proprietary 7

MPLS-TP KEY REQUIREMENTS MPLS-TP Key Requirements Key requirements for MPLS-TP can be divided into five main areas: management, OAM, control and data planes, and protection. Management Control and management planes must support logical and physical separation from the data plane. Operators must be able to operate an MPLS-TP network completely (including OAM) in the absence of any control plane protocols for dynamic configuration. Static provisioning of transport paths via an NMS/OSS must be supported (i.e. via the management plane without any dependency on routing or signaling protocols (e.g., GMPLS, OSPF, IS-IS, RSVP, BGP, LDP, etc.). Must operate under a common operation, control, and management paradigm with respect to other transport technologies (e.g., SDH, OTN, or WDM). Must be operable with a centralized NMS system. OAM MPLS-TP OAM must be able to operate without IP functionality and without relying on control and/or management planes. MPLS-TP OAM and data must share the same fate. Data Plane It must be possible to operate and configure the MPLS-TP data (transport) plane without any IP functionality. Must support both unidirectional and bidirectional point-to-point (P2P) transport paths. The forward and backward directions of a bidirectional transport path must be capable of following the same path within the MPLS-TP network. Must support transport paths through both single and multiple domains. MPLS-TP must support P2P or point-to-multipoint (P2MP) transport paths. Control Plane An MPLS-TP control plane must support mechanisms for partitioning the network under control into separate peer or hierarchical control domains. MPLS-TP must support any network topology and be able to support increasing bandwidth demands, topology, number of customers, or number of services incrementally. 8 ECI Telecom Ltd. Proprietary

MPLS-TP KEY REQUIREMENTS Protection Must be able to deliver the same degree of QoS that has been delivered by SDH/SONET systems. Must support a method to offer packet loss objectives comparable to those in TDM transport networks (only due to bit errors). Must support transport network-style protection switching mechanisms to provide the carrier-class recovery time for node, link, and LSP failures. ECI Telecom Ltd. Proprietary 9

MPLS VS. IP-MPLS MPLS vs. IP-MPLS IP-MPLS or L3 MPLS is usually used by routers (although some routers support only L2 MPLS). As can be seen from the comparison below, both MPLS-TP and IP-MPLS provide the same functionality. However, MPLS-TP s connectionorientation and use of static configuration, enables it to provide additional or enhanced carrier grade performance as expected from transport products. Issue ECI s MPLS-TP ( Transport MPLS) IP-MPLS ( Routers MPLS ) Supported Topologies L2 MPLS P2P MP2MP Hub-and-spoke VPWS VPLS H-VPLS P2P MP2MP Hub-and-spoke VPWS VPLS H-VPLS L3 MPLS No, but some routers support only L2 MPLS Transport- Oriented Service Efficient Carrier Class IPTV Solution Unidirectional Tunnels Bidirectional Tunnels Pseudowires (PW) MPLS over SDH (MOT) MPLS over Ethernet (MoE) Protection Management Solution, MPLS LSP and PWE using deterministic (connectionoriented) scheme Rooted P2MP Multicast Tree based on P2MP tunnels IGMP snooping Link and Node FRR 1:1 tunnel protection Dual FRR protection Fast IOP: 1+1 card protection NMS-based o GUI-based management o SDH like point-and-click provisioning o Advanced Automatic Pathfinding o Handles Connection Admission Control (CAC) o Handles Shared Risk Link Group (SRLG) No, use MPLS in a connectionless mode based on routing protocols L3 Multicast based on nondeterministic and more complex PIM protocol IGMP snooping No No Link and Node FRR LSP Reroute CLI based management only CAC is limited to node-based CAC 10 ECI Telecom Ltd. Proprietary

MPLS VS. IP-MPLS Issue ECI s MPLS-TP ( Transport MPLS) IP-MPLS ( Routers MPLS ) Signaling OAM Port Types Support QoS Traffic Management (TM) PHP (Penultimate Hop Popping) LSP Merge: May result misconnection and complex OAM ECMP (Equal Cost Multiple Path) No o Statically configure LSP/PWE via management plane Service OAM 802.1ag Y.1731 POAM Tunnel OAM Y.1711 MPLS-TP BFD FE 1G 10G E-LSP (multi-traffic class per tunnel) multi-cos bandwidth L-LSP (single traffic class per tunnel for mission critical applications) Enhanced support Dedicated queuing per tunnel (better performance for sensitive traffic) No need for PHP wire-speed processing Don t use LSP merge: Real connection-oriented solution Not supported o o o LDP both for tunnels and PWs RSVP-TE for tunnels OSPF/IS-IS Service OAM 802.1ag BFD FE 1G 10G E-LSP single CoS Bandwidth Limited support Aggregate traffic behavior only Use PHP (in order to maximize performance) Use LSP merge Not connection oriented Allows traffic within one LSP to be routed along multiple networ paths requires additional IP header and MPLS label processing, and complicates OAM ECI Telecom Ltd. Proprietary 11

ECI SUPPORT OF MPLS-TP ECI Support of MPLS-TP MPLS-TP is the natural outcome of ECI s approach over the years towards carrierclass MPLS support managed and controlled by its LightSoft NMS. As a leader in the field of transport networking, ECI was among the first to identify the key attributes service providers seek when starting to use Ethernet in their transport networks, and offered MPLS solutions even before the standard was ratified. This positions ECI as one of the first suppliers to support the MPLS-TP standard, as soon as it is ratified, with just a simple software update to address changes that will be introduced. It is important to note that, in cases where MPLS-TP attributes are not required, ECI supports simpler schemes like Provider Bridge (PB) with the same hardware that is able to support MPLS-TP. This flexible approach enables ECI to tailor-make the most cost-effective offering for a customer s specific needs by combining, for example, PB in the access with MPLS-TP at the core of the metro. The solution is future-ready, and with a simple remote software upgrade, can be changed to support MPLS-TP and so accommodate changes in network topology, services, or the business model. MPLS-TP support across ECI s transport product lines (including BroadGate, XDM, and NPT (Native Packet Transport)) enables E2E QoS assurance across network domains. MPLS advantages are no longer limited to the network core, but expand throughout the entire metro area. ECI platforms support MPLS over Transport (MoT), e.g. over SDH/SONET, as well as MPLS over Ethernet (MoE), using Ethernet as a transport layer as well as a service. This opens the door to a unified network, seamlessly incorporating both NPT and MSPP products. A service can be provisioned starting with a TDM-based MSPP to end with an NPT platform, and vice versa. ECI sees MPLS-TP as a key attribute in lowering next-generation packet transport network TCO by enabling MPLS functionality without the cost and complexity associated with extending it to the metro. 12 ECI Telecom Ltd. Proprietary

ABOUT ECI TELECOM About ECI Telecom ECI Telecom is a leading global provider of intelligent infrastructure, offering platforms and solutions tailored to meet the escalating demands of tomorrow's services. Our comprehensive 1NET approach defines ECI s total focus on optimal transition to Next-Generation Networks, through the unique combination of innovative and multi-functional network equipment, fully integrated solutions and all-around services. For more information, please visit http://www.ecitele.com. ECI Telecom Ltd. Proprietary 13

www.ecitele.com ECI Headquarters Tel: +972 3926 6555 Fax: +972 3928 7100 1Net defines ECI s focus on facilitating our customers' optimal transition to Next-Generation Networks, through the unique combination of innovative and multi-functional network equipment, fully integrated solutions and all-around services EMEA Tel: +44 1256 388000 Fax: +44 1256 388143 RoAPAC Tel: +65 6505 1960 Fax: +65 6505 1999 CIS Tel: +972 3926 8548 Fax: +972 3926 6452 Americas Tel: +1 954 772 3070 Fax: +1 954 351 4404 India (Mumbai) Tel: +91 22 6715 5555 Fax: +91 22 6675 8973 Copyright 2012 ECI Telecom. All rights reserved. Information in this document is subject to change without notice. ECI Telecom assumes no responsibility for any errors that may appear in this document.