文档介绍：新一代互联网网络层协议IPv6
Outline
Protocol Background
Technology Highlights
Enhanced Capabilities
Transition Issues
Next Steps
新一代互联网的定义和主要特征
目前还没有统一的严格定义,新一代互联网将是一个渐进的发展过程
目前已取得共识的主要特征
更大:IPv6的地址空间,网络的规模更大,接入网络的终端种类和数量更多,网络应用更广泛
更快:100Mbps以上的端到端高性能通信
更安全可信:对象识别,身份认证和访问授权,数据加密和完整性,可信任的网络
更及时:组播服务,服务质量(QoS),大规模实时交互应用
更方便:基于移动和无线通信的丰富应用
更可管理:有序的管理、有效的运营、及时的维护
更有效:有盈利模型,获得重大社会效益和经济效益
Why a New IP?
1991 – ALE WG studied projections about address consumption rate showed exhaustion by 2008
Bake-off in mid-1994 selected approach of a new protocol over multiple layers of encapsulation
What Ever Happened to IPv5?
0 IP March 1977 version (deprecated)
1 IP January 1978 version (deprecated)
2 IP February 1978 version A (deprecated)
3 IP February 1978 version B (deprecated)
4 IPv4 September 1981 version (current widespread)
5 ST Stream Transport (not a new IP, little use)
6 IPv6 December 1998 version (formerly SIP, SIPP)
7 CATNIP IPng evaluation (formerly TP/IX; deprecated)
8 Pip IPng evaluation (deprecated)
9 TUBA IPng evaluation (deprecated)
10-15 unassigned
Technologies & efforts to slow the consumption rate
Dial-access / PPP / DHCP
Provides temporary allocation aligned with actual endpoint use
Strict allocation policies
Reduced allocation rates by policy of “current-need” vs. previous policy based on “projected-maximum-size”
CIDR
Aligns routing table size with needs-based address allocation policy. Additional enforced aggregation actually lowered routing table growth rate to linear for a few years
NAT
Hides many nodes behind limited set of public addresses
Would increased use of NATs be adequate?
NO!
NAT enforces a “client-server” application model where the server has topological constraints
They won’t work for peer-to-peer or devices that are “called” by others (., IP phones)
They inhibit deployment of new applications and services, because all NATs in the path have to be upgraded BEFORE the application can be deployed
Return to an End-to-End Architecture
Global