A Framework for Scalable Global IP-Anycast Sigcomm 2000, Dina Katabi Presented by Wei Yu

Outline n Motivation n Introduction n Background work n Idea & design detail n Performance Evaluation n Result

Motivation n A scalable architecture for Global IP- Anycast n Existing design drawback –Global Distribute route to individual group =>not scalable n Idea: dividing inter-domain routing into two parts: –Build inexpensive anycast route, consume no BW and storage space –Edge domain generate anycast routes according to the interest.

What is Anycast? n Anycast ( RFC 1546): sender to access the nearest of a group of receiver sharing anycast address n Application: service discovery & host autoconfiguration n EX: replicated FTP server, mirror web server

Background & related work n IP level solution: proposed by IPv6 anycast routing n Application level solution: Need directory system –disadvantage: overhead to collection information lack bootstrap mechanism –advantage: easy to deploy n Difficulty: scalable architecture –defies hierarchical aggregation –routing table

Idea n Unicast routing paradigm problem –waste routing resources –ex: US & Lindon => devote more resource to frequency access anycast group n Using cache technology n Using edge domain resources, why? –Prevent wasting routing resources –push most of work to edge domain n Edge domain discover, store and maintain anycast route

Design detail n Address architecture

Design Detail n Anycast group classification

Design Detail n Routing internal anycast group: –using unicast routing protocol n Routing unpopular anycast group –using default route to forward packets n Routing popular anycast group –initial search, receiving search, receiving reply, search scope: TTL

Design details Learning routes to popular anycast group

Performance Evaluation n Main results –nearest route –overhead ( millions global group) n Supposition –provide lower bound on efficiency –upper bound of overhead

Success route performance

Overhead

Scalable

Question ?