DSLite_Implementation_Experiences.pdfVIP

DS-Lite: Implementation experience and views CMCC workshop, Nov 2009 B. Patil/T. Savolainen/F. Junior 1 © 2009 Nokia Overview of DS-Lite 2 © 2009 Nokia Need for IPv4-over-IPv6 tunneling • Earlier, tunneling discussions focused on IPv6-over-IPv4: “How to reach IPv6 domain from IPv4-only networks?” • However, due to the looming IPv4 address exhaustion, the bigger question now is: “How to reach IPv4 domains from IPv6-only networks”? • There are various methods, and one such is Dual-Stack Lite • DS-Lite looks like Dual-Stack for devices/applications, but in reality it: Automatically tunnels IPv4 over IPv6 to Address Family Transition Router (AFTR) AFTR aka Carrier Grade NAT aka Large Scale NAT aka DS-Lite tunnel concentrator AFTR aka Carrier Grade NAT aka Large Scale NAT aka DS-Lite tunnel concentrator 3 © 2009 Nokia DS-Lite provides • IPv4 connectivity to hosts and/or home routers (CPEs) that are provisioned with only IPv6 addresses • No need for private addresses in operator’s network • Public IPv4 addresses, previously used in operators’ intra, are harvested into more productive use • Dual-Stack connectivity for hosts connected to IPv6-only access networks • Less need to maintain IPv4 or dual-stack access networks • A lightweight solution for providing IPv4 connectivity over IPv6 only access • Single NAT – i.e. no need to have multiple layers of NATs • Avoidance of protocol translation – and problems caused by it • Multiplexing limited number of public IPv4 addresses for even larger number of customers than before • Automatic tunnel establishment • Tunnel endpoint (AFTR) is discovered with Stateless DHCPv6 (new option defined) • Port forwarding capability on the AFTR • With technologies such as: Web-UI, NAT-PMP, UPnP, A+P • In 3GPP, would enable IPv4 connectivity over IPv6-only PDP