1

The CERNET Optical Network

Xing Li

2004-06-08

2

Outline

Introduction

CERNET Optical Transport Network

CERNET IP Backbone

Operation Experience

Next Generation Plan

Conclusion

3

CERNET Statistics

China Education and Research Network (CERNET) is the first and largest academic Internet backbone in China.

8 national Pops are connected via 2.5Gbps DWDM links 30 provincial Pops are connected via multiple 155Mbps SDH links 38 GigaPops distributed in 36 cities, covering all the provinces in Mai

nland China. 300 campus networks connect to their nearest Pops via 100Mbps-1Gb

ps links. 1,500 education and research institutions connected and provide Intern

et connectivity 15 million users 320 million students/school kids

4

CERNET Dark Fiber Layout

5

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

6

CERNET IP Backbone

7

CERNET Operation Experience

Bandwidth is never enough

Protection can be done in layer 3

Unified network management system is desirable

Flow control and security is essential

8

Bandwidth is never enough But after 3 to 12 months, the links were congested again and the users were

shouting for a higher bandwidth. It seems that the optical network is the only

solution.

9

Protection can be done in layer 3

北京

郑州

西安

武汉 合肥 上海

南昌 杭州

广州

成都

沈阳

南宁

天津

福州

重庆

济南大连

长春 哈尔滨

长沙

南京

厦门

兰州

深圳

石家庄

银川西宁

乌鲁木齐

昆明贵阳拉萨

太原呼和浩特

青岛

桂林海口

10

Unified network management system is desirable

11

Flow Control and Security is Essential

12

University Connectivity Demand

16 Million students enrolled in 2003 universities and institutes located

in more than 260 cities in Mainland China in year 2002.

The average number of enrollment per university/institute is about 8,0

00 students.

If 1 Mbps connectivity is required per student, an average sized campu

s network will need about 8 Gbps of aggregated bandwidth.

When 80 vs. 20 rule applied, the CERNET backbone should provide 4

Tbps aggregated bandwidth reaching more than 260 cities.

For one IP address per student assignment, 1 /8 space is needed.

13

School Connectivity Demand

The student population in Mainland China is about 300 Million in 200

2. There are about 1.2Million schools.

If 0.5 Mbps connectivity is required per head with 80 vs. 20 rule appli

ed, the CERNET backbone should provide 30 Tbps aggregated bandw

idth.

For one IP address per head assignment, 19 /8 spaces are needed.

14

Economical Considerations

The calculated bandwidth should be provided with affordable price,

which should be able cover

– the link to the global Internet

– the port to other Internet backbone in China

– the construction and operation CERNET backbone

– the metropolitan networks and the campus networks

What can be collected

– University student 30 RMB/month

– School kids 3 RMB/month

15

CERNET optical infrastructure upgrade plan

上海

沈阳

大连

长春 哈尔滨

北京

郑州西安

武汉

合肥

杭州

广州

成都

天津

重庆

济南

厦门

长沙

南京

福州

兰州

银川西宁

乌鲁木齐

太原呼和浩特

昆明贵阳拉萨

南宁

深圳桂林海口

南昌

石家庄青岛

16

CERNET2 plan

北京

郑州西安

武汉 合肥 上海

杭州

广州

成都

沈阳

天津

重庆

济南

厦门

大连

长春 哈尔滨

长沙

南京

兰州

10G

2.5G

用户接入网 用户接入网 用户接入网

用户接入网 用户接入网

用户接入网

用户接入网

用户接入网用户接入网用户接入网

用户接入网

用户接入网

用户接入网

用户接入网

用户接入网用户接入网

用户接入网 用户接入网 用户接入网

10 Gbps to 5 cities, 2.5Gbps to 20 cities

17

Advanced Applications

18

Conclusions

China is a developing country, the education modernization is the key

for its future development.

Providing Internet connectivity to all the universities and schools is

one of the major step in the modernization process.

CERNET architecture board is planning to upgrade the national

backbone, the metropolitan networks and the campus networks again

for higher performance and better manageability for affordable cost.

The scalability of providing Internet services to all the educational

population in Mainland China is the key of success.