We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byAlondra Sidebotham
Modified over 2 years ago
NEW OUTLOOK ON MULTI-DOMAIN AND MULTI-LAYER TRAFFIC ENGINEERING Adrian Farrel AUSNOG, Sydney, September 2013
2 Copyright © 2013 Juniper Networks, Inc. WHY DO WE CARE ABOUT MULTI-LAYER NETWORKS? What is a layer? Most obvious definition is technology layers Packet-over-optical is seeing a resurgence of interest MPLS-over-MPLS is layering There are also sub-layers of optical technologies Routers are connected together Hope that is not a shock to you Router inter-connect does not need to be a p2p link Mesh transport networks offer ways provide variable connectivity and maximise return from a set of transport resources Many network services are examples of layering VPNs are best example Pseudowires count as well
3 Copyright © 2013 Juniper Networks, Inc. WHAT PROBLEMS ARE WE TRYING TO SOLVE? We need to make connectivity requests from a client network to a server network Typically the client cannot see / understand the server topology Client networks / nodes typically multi-homed to a server network Client networks may be connected to multiple server networks Client needs to understand client-layer reachability across the server networks Server-layer connectivity may be through a concatenation of server networks
4 Copyright © 2013 Juniper Networks, Inc. SOME OLD VIEWS OF LAYERING User to Network Interface No routing exchange No hints about resolving dual homing No hints about client layer reachability Protocol solutions from ITU-T, OIF, and IETF UNI request is a stab in the dark UNI
5 Copyright © 2013 Juniper Networks, Inc. FLOODING WOULD BE CRAZY Well, it would, wouldn’t it? Flooding means… Telling the client network about all of the links and nodes in the server network A shared IGP Two IGP instances GMPLS actually supports this Networks usually under different administrations Scaling is a real concern It can get messy with multiple server networks Client network will not understand server links All those optical parameters etc. Really don’t want to try to send packets down optical links
6 Copyright © 2013 Juniper Networks, Inc. LINK AGGREGATION DOESN’T QUITE DO THE JOB Disadvantages of link aggregation Waste of transport resources Under-use of dedicated resources n 2 scaling issues (full mesh) Complexity of server layer planning and management Edge nodes need more server layer resources (line cards, lasers, etc.) Client has no idea of physical path Cost of client services is high Protection may not be real Need for frequent advertisement updates Every time resource is used on a component path Computationally expensive to aggregate Multiple paths Multiple constraints Advantages of link aggregation Direct, any-to-any connectivity Minimize delay in provisioning new client services Server layer treated as a set of logical links No worries about client connectivity Simplified client network management Redundant connections in case of failure
7 Copyright © 2013 Juniper Networks, Inc. NODE AGGREGATION DOESN’T CUT IT EITHER Disadvantages of aggregation No consideration of path properties No visibility into disjoint paths Limited cross-connect ability is hidden In particular when network is partitioned Issues with wavelength continuity There are ways to handle limited cross-connects in GMPLS advertisements, but higher layer network will not understand them Advantages of Aggregation Very simple model Scales well Does not need frequent updates
8 Copyright © 2013 Juniper Networks, Inc. HOW PCE ADDRESSED THE PROBLEM A L M K J I H G E F C B D VNT Manager PCE A PCE for each network Hides topology of one network from the other network Higher layer PCE reports absent connectivity in higher layer to Virtual Network Topology Manager VNTM consults lower layer PCE and then provisions connectivity PCE
9 Copyright © 2013 Juniper Networks, Inc. PERHAPS THE CLIENT CAN BE IN BOTH NETWORKS This is a variation of the UNI model The UNI is within the node Only the edge nodes need to be aware of the core network The edge node can make choices about the path across the server network The edge node could determine potential connectivity and advertise as potential links in the client network But… It doesn’t help planning end-to-end paths The edge node (probably a router) needs to be aware of All server technologies Complex TE parameters (such as optical constraints) All vendor-specific issues in the server network UNI
10 Copyright © 2013 Juniper Networks, Inc. TWO UNASKED QUESTIONS Do we *really* want provisioning in the server layer auto- triggered by activity in the client layer? Server may be 100G lambda Client may be a UDP packet There may be commercial implications When can I start to send data using the virtual link? Many optical circuits need tuning and testing first
11 Copyright © 2013 Juniper Networks, Inc. ABSTRACT LINKS A virtual link is a link created out of a server-layer LSP. Advertised into the client-layer IGP just like any other link An abstract link is the possibility of a virtual link. It is a link that would be formed if an LSP was set up to support it. Installed in the client-layer Traffic Engineering Database Maybe by IGP or by BGP-LS Policy is used to determine which abstract links to advertise I.e. not all potential links Allows stability of selection without frequent re-compute / re-advertisement Just key reachability with basic constraints Allows knowledge of server network resources, topology, constraints, etc. to be hidden from client Client layer can see what links might be established Ask for them to be turned up if needed Reachability is known within the client layer Abstract converted to virtual link as service request from client layer LSP is set up (and tuned and tested) Link is advertised into client IGP
12 Copyright © 2013 Juniper Networks, Inc. INTRODUCING A CONNECTIVITY LAYER IGP in Server Layer Node X determines abstract XY It’s a policy thing IGP in Connectivity Layer Consists of “Access Links” and “Abstract Links” Update “abstract” to “real” when server LSP set up by NMS action Node V determines abstract VW IGP in Client Layer Consists of normal “Client Links” and “Abstract Links” Update “abstract” to “real” when client LSP set up by NMS action Client Connectivity Layer Server X V W Y
13 Copyright © 2013 Juniper Networks, Inc. GENERAL APPLICABILITY TO THE VPN It’s a layered network It has multi-homing and reachability issues We need to provision TE connectivity Discussion is about better VPN enablement for the carrier
14 Copyright © 2013 Juniper Networks, Inc. APPLICABILITY TO PEER DOMAINS Strong driver for tier 1 VPN providers Need to leak “TE reachability” without flooding mega-data Key components are Abstract links Connectivity Layer BGP-LS PCE
Page 1 iPOP2009, Tokyo, Japan Selecting Domain Paths in Inter-Domain MPLS-TE and GMPLS Adrian Farrel, Old Dog Consulting Daniel King, Old Dog Consulting.
Limit for content Do not exceed Limit for content Do not exceed Limit for content Do not exceed Limit for content Do not exceed 1 Aria Networks Multi-domain.
MPLS and GMPLS Li Yin CS294 presentation. Outline Part I: MPLS Part II: GMPLS Part III: The reality check.
1 Designing a future Internet: Architecture and requirements David Clark MIT CSAIL August 2008.
Introduction to computer networking Objective: To be acquainted with: The definitions of networking Network topology Network peripherals, hardware and.
OLD DOG CONSULTING MPLS-TE Doesn’t Scale Adrian Farrel Old Dog Consulting
Rapid Convergence in IP Networks: Tom Scholl, AT&T Labs NANOG 46.
Multihoming and Multi-path Routing CS 7260 Nick Feamster January
Routing An Engineering Approach to Computer Networking.
1 Computer Networks: A Systems Approach, 5e Larry L. Peterson and Bruce S. Davie Chapter 9 Applications Copyright © 2010, Elsevier Inc. All rights Reserved.
1 Chapter 7 Local Area Networks : The Basics Data Communications and Computer Networks: A Business Users Approach.
Multihoming and Multi-path Routing CS 4251: Computer Networking II Nick Feamster Fall 2008.
How to Multi-Home Avi Freedman VP Engineering AboveNet Communications.
Ken Birman Cornell University. CS5410 Fall
Internet Exchange Points (IXPs) Scalable Infrastructure Workshop.
Video Services over Software-Defined Networks 1 A. Murat Tekalp December 6, 2013.
Version 4.1 CCNA Discovery 2– Chapter 7. Contents 7.1: ISP Services : TCP / IP Protocols 7.2: 7.3: DNS 7.3: 7.4: Application Layer Protocols 7.4.
The MANTICORE Project: Providing Users with a Logical IP Network Service Eduard Grasa, Fundació i2cat.
Chapter 7 Local Area Networks: The Basics. 2 Primary Function of a LAN File serving – large storage disk drive acts as a central storage repository Print.
Identity and Locators in IPv6 IAB Meeting IETF 60 August 2004.
Copyright © 2006 Juniper Networks, Inc. 1 End-to-End Network Services: What is Really Missing? Mark Williams Liaison, R&E Networks, APAC.
Improving Internet Availability Nick Feamster Georgia Tech.
Windows 2008 Active Directory Configuration – Week 3 of 6 Microsoft Test: Mark McCoy MCSE, CNE, CISSP.
RMS and Scheduling for Future Generation Grids Ramin Yahyapour University Dortmund Leader CoreGRID Institute on Resource Management and Scheduling CoreGRID.
Scalability and efficiency: Introducing a new mechanism to the internet must not jeopardize its efficiency. Enhancing IP for mobility must not generate.
Networking and Communication: Bus, switch, and network structures and protocols, I/O, Synchronization Ray Tsai, Shui wing Yim CS490 (Fall 2003) 10/20/03.
© 2004 SafeNet, Inc. All rights reserved. Mobike Protocol Design draft-ietf-mobike-design-00.txt Tero Kivinen
ENMA: Co-operation in the corporation Mort (Richard Mortier) MSR-Cambridge September 2004.
Networking Fundamentals John Bellavance CCNI. Data Networks Developed because companies wanted to exchange info over long distances. At first they used.
Data Analysis 1 Chapter 2.1 V3.1 Napier University Dr Gordon Russell.
© 2016 SlidePlayer.com Inc. All rights reserved.