Towards TCAM-based scalable virtual routers

As the key building block for enabling network virtualization, virtual routers have attracted much attention recently. In a virtual router platform, multiple virtual router instances coexist, each with its own FIB (Forwarding Information Base). The small amount of high-speed memory in a physical router platform severely limits the number of FIBs supported, which leads to a scalability challenge. In this paper, we present a method towards TCAM (Ternary Content Addressable Memory) based scalable virtual routers, through a merged data structure that enables the sharing of prefixes from several FIBs in TCAMs. Based on this data structure, we propose two approaches to merge multiple FIBs in TCAMs, paving the way for scalable virtual routers. Experimental results show that, by using the two approaches for storing 14 full IPv4 FIBs, the TCAM memory requirement can be reduced by about 92% and 82% respectively, compared with the conventional approach of treating FIBs as independent entities.

[1]  Raouf Boutaba,et al.  A survey of network virtualization , 2010, Comput. Networks.

[2]  Bin Liu,et al.  A TCAM-based distributed parallel IP lookup scheme and performance analysis , 2006, IEEE/ACM Transactions on Networking.

[3]  Gaogang Xie,et al.  A hybrid IP lookup architecture with fast updates , 2012, 2012 Proceedings IEEE INFOCOM.

[4]  Nick Feamster,et al.  SwitchBlade: a platform for rapid deployment of network protocols on programmable hardware , 2010, SIGCOMM '10.

[5]  Viktor K. Prasanna,et al.  Towards On-the-Fly Incremental Updates for Virtualized Routers on FPGA , 2011, 2011 21st International Conference on Field Programmable Logic and Applications.

[6]  Mark Handley,et al.  Towards high performance virtual routers on commodity hardware , 2008, CoNEXT '08.

[7]  Fred Kuhns,et al.  Supercharging planetlab: a high performance, multi-application, overlay network platform , 2007, SIGCOMM '07.

[8]  T. N. Vijaykumar,et al.  TreeCAM: decoupling updates and lookups in packet classification , 2011, CoNEXT '11.

[9]  Viktor K. Prasanna,et al.  Memory-efficient and scalable virtual routers using FPGA , 2011, FPGA '11.

[10]  W. Lu,et al.  Low-Power TCAMs for Very Large Forwarding Tables , 2010, IEEE/ACM Transactions on Networking.

[11]  Paul Francis,et al.  SMALTA: practical and near-optimal FIB aggregation , 2011, CoNEXT '11.

[12]  Jing Fu,et al.  Efficient IP-address lookup with a shared forwarding table for multiple virtual routers , 2008, CoNEXT '08.

[13]  Rabi N. Mahapatra,et al.  TCAM architecture for IP lookup using prefix properties , 2004, IEEE Micro.

[14]  Xin Zhao,et al.  On the Aggregatability of Router Forwarding Tables , 2010, 2010 Proceedings IEEE INFOCOM.

[15]  Laxmi N. Bhuyan,et al.  EaseCAM: an energy and storage efficient TCAM-based router architecture for IP lookup , 2005, IEEE Transactions on Computers.

[16]  Francis Zane,et al.  Coolcams: power-efficient TCAMs for forwarding engines , 2003, IEEE INFOCOM 2003. Twenty-second Annual Joint Conference of the IEEE Computer and Communications Societies (IEEE Cat. No.03CH37428).

[17]  Walid Dabbous,et al.  Survey and taxonomy of IP address lookup algorithms , 2001, IEEE Netw..

[18]  Devavrat Shah,et al.  Fast Updating Algorithms for TCAMs , 2001, IEEE Micro.

[19]  Viktor K. Prasanna,et al.  Multiroot: Towards Memory-Efficient Router Virtualization , 2011, 2011 IEEE International Conference on Communications (ICC).

[20]  Fang Hao,et al.  Building Scalable Virtual Routers with Trie Braiding , 2010, 2010 Proceedings IEEE INFOCOM.

[21]  Gaogang Xie,et al.  PEARL: a programmable virtual router platform , 2011, IEEE Communications Magazine.

[22]  Huan Liu.  Routing Table Compaction in Ternary CAM , 2002, IEEE Micro.