90 likes | 227 Views
Using Mobility Support for Request-Routing in IPv6 CDNs. Arup Acharya and Anees Shaikh TJ Watson Research Center Presented by Renu Tewari. Request-Routing in CDNs. RR directs client HTTP requests to “proximal” server In IPv4 CDNs, RR primarily via DNS
E N D
Using Mobility Support for Request-Routing in IPv6 CDNs Arup Acharya and Anees Shaikh TJ Watson Research Center Presented by Renu Tewari
Request-Routing in CDNs • RR directs client HTTP requests to “proximal” server • In IPv4 CDNs, RR primarily via DNS • Key observation: RR is congruent to IP mobility • use mobile IP mechanisms for redirection • no need to overload DNS • In IPv4, mobility requires deployment of “mobility agents” • existing hosts remain unchanged • however, all packets routed via home agent triangular routing • IPv6 offers native mobility support • support present in any IPv6 node • direct routing between mobiles and correspondents • RR can use mobility mechanisms without modification
12.100.104.5 (TTL = 0) www.abc.com? www.abc.com? ns.abc.com (TTL = 1d) www.abc.com? 12.100.104.5 DNS Request Routing (IPv4) CDN servers modifiednameserver 63.64.105.4 12.100.104.5 root nameserver local ns client
IPV RR in IPv6 using mobility support • resolve name to an IP address (IPv) IPv6 RR (IPV) origin server DNS server CDN servers www.abc.com? local NS client
home agent src: IPC dest: IPV TCP SYN TCP SYN mobile node correspondentnode IPv6 Request-Routing (cont.) • RR chooses proximal server (IPL) IPv6 RR (IPV) • forwards SYN pkt to IPL in IP-in-IP tunnel f(IPC, IPV) = IPL CDN server (IPL) client (IPC)
src: IPC dest: IPV TCP SYN src: IPL dest: IPC HA: IPV bind upd bindingcache SYN/ACK IPV IPL IPv6 Request-Routing (cont.) • CDN server sendsIPv IPL mapping to client via a binding update, piggybacked on SYN/ACK IPv6 RR (IPV) • client creates binding cache entry CDN server (IPL) client (IPC)
src: IPC dest: IPL RH: IPV bindingcache HTTP GET IPV IPL IPv6 Request-Routing (cont.) • subsequent client pkts sent to IPL (IPv placed in routing header) • TCP endpoint: < IPc ,IPv> IPv6 RR (IPV) CDN server (IPL) client (IPC)
Additional remarks • IPv6 mobility provides an alternate mechanism for RR • RR policies and metrics must be implemented at the home agent • Functionality similar to DNS, without some problems • IPv6 RR sees actual client address – improved accuracy • CDN server can use lifetime field in binding cache to control duration of binding • Take advantage of large address space in IPv6 • map CDN customers to distinct (virtual) IP addresses • use additional addresses for granular content-based-routing (e.g., streaming, images, etc.)