Download - Softwire Mesh Example CERNET2
Softwire Mesh ExampleCERNET2
Xing Li
<2005-11-07>
Outline
CERNET2 Briefing
CERNET2’s IPv4 over IPv6 requirement
Configurations
Summary
CERNET2 Briefing
CERNET2 is the largest backbone of CNGI
project
CERNET2 is running on top of CERNET
Transport network
CERNET2 is a “pure IPv6” backbone
The users of CERNET2 require high
performance IPv4 applications
CNGI Backbones
XinJiang
XiZang
兰州
NeiMengGu
NingXia
西安
ShanXi
HeBei
郑州武汉
南京
合肥上海
YunNan
GuiZhou
长沙 JiangXi
厦门GuangXi
HaiNan
长春JiLin
大连
台湾深圳
成都
QingHai 济南
重庆
CERNET ChinaTelecom CNC/CST
ChinaMobileUnicom
CERNET
杭州
福州
沈阳
青岛
天津
香港
HeiLongJiang
LiaoNing
北京
ShanDong
JiangSu
ZheJiang
FuJian
GuangDong
HuNan
HuBei
HeNan
AnHui
ShaanXi
GanSu
SiChuan
ChinaRail
昆明
广州
CERNET Transport Network
大连
北京
郑州
石家庄
武汉 合
肥
南京
上海
长沙
南昌 杭
州
广州
福州
成都
昆明
重庆
厦门
海口
桂林
沈阳
哈尔滨
天津
济南
南宁
深圳
太原
青岛
BJ
zhzXA
CD WH
GZ xmn
hzh
SHNJhef
dlnSY chc hrb
chq
chs
大连
北京
郑州
石家庄
武汉 合
肥
南京
上海
长沙
南昌 杭
州
广州
福州
成都
昆明
重庆
厦门
海口
桂林
沈阳
哈尔滨
天津
济南
南宁
深圳
太原
青岛
BJ
zhzXA
CD WH
GZ xmn
hzh
SHNJhef
dlnSY chc hrb
chq
chs
tjn
jnn
lzh
CERNET2 IPv6 Technical Specification
25 Pops in 20 cities linked via 2.5Gbps to 10 Gbps
trunks
IPv6 only Backbone AS23910
2001:DA8::/32
IGP - OSPFv3
EGP - BGP4+ peering with
• 25 regional Pops
• 5 CNGI backbones
• CERNET IPv6, CJ-IPv6, NSFCNET, 863-testbed, 3Tnet, etc
100+ access networks
CERNET2 Topology
CERNET2 Peering
CERNET2’s IPv4 over IPv6 App. Requirement
High Throughput Video
Multicast Video
CERNET2’s VisionIPv4 over IPv6 may help
Built and/or upgrade a backbone without
worrying the limited IPv4 address, have a better
performance-to-cost ratio and in a “politically
correct” manner
Support existing IPv4 access networks
Support existing IPv4 applications
And it may help for the transition from IPv4
to IPv6 in a cost effective, incremental and
seamless fashion
Configuration (1)
v4
v4
v4
BJ
GZ
SH
Only BJ, SH and GZ provide IPv4 serviceOther nodes are IPv6 only
Allow manual configurationMust support unicast and multicast
Global IPv4 Internet
Configuration (2)
v4
v4
v4
BJ
GZ
SH
All Pops provide IPv4 service
hzh
xmn
WH NJ
hrf
jnn
SY
dln
chc hrb
zhzXA
CD SHchq
lzh
v4
v4
v4
v4v4v4
v4v4 v4
v4 v4 v4
v4
v4v4
Prefer auto-configurationMust support unicast and multicast
chs
tjn v4
Global IPv4 Internet
Access Network’s View
CERNET2 Backboneedgeedge
edge edge
IPv4 Access
IPv4 Access
IPv4 Access
IPv4 Access
IPv6 Access IPv6 Access
IPv4 static or eBGP peering Encapsulation and Setup
Same as a dual-stack
backbone
Pure IPv6backbone
softwire
Softwire Mesh Scenarios (IPv4/IPv6)
IPv6 TransitAFBRAFBR
AFBR AFBR
IPv4 accessisland
IPv4 accessisland
IPv4 accessisland
IPv4 accessisland
IPv6 access IPv6 access
IPv4 static or eBGP peering Encapsulation and Setup
Same behavior as a dual-stack
backbonesoftwire
Softwire Mesh Scenarios (IPv6/IPv4)
IPv4 TransitAFBRAFBR
AFBR AFBR
IPv6 accessisland
IPv6 accessisland
IPv6 accessisland
IPv6 accessisland
IPv4 access IPv4 access
IPv6 static or eBGP peering Encapsulation and Setup
Same behavior as a dual-stack
backboneSoftwire
Notes Typical number of Ps, PEs, and CPEs?
P 20 (today) : 50 (CERNET2)
PE 10 (today) : 100 (CERNET2)
CPE 100 (today) : X0000 (CERNET2)
Why not use CPE to provide the functionality? ISP business considerations
Why not use layer 2 service? Point to point scalability and multi-point to multi-point broadcast storm
Configuration on operational overhead
Mesh problem more similar to L3 VPN case
Why not run dual stack on P routers Political and economical considerations
Need to get to V6 only network
Summary IPv4 over IPv6 service should support
The IPv4 access network should behave as if it is connecte
d to a IPv4 or dual-stack backbone
It should support both IPv4 unicast and multicast
Initial requirement is inside an AS domain, but if possible, c
ross AS’s mechanism is desirable
Encapsulation and control protocol includes Encapsulation type
End point setup
MTU
Management requires MIB