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Effect of routing on RTTs to 2 sites in Hangzhou, China Network logo

Les Cottrell. Page created: January 8, 2004.

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While looking for a site/host to monitor in Hangzhou China, we contacted Jing Shen of ZheJiang University, P.R.China. He pointed us to two sites in Hangzhou.
You could try to ping our lab Web server : On the other hand, China Research & Education Network connects to ChinaNet with around 500Mbps link now. If you want to monitoring connection to ChinaNet with about 5Gbps internet connection, you could ping to HangZhou Telecom website
However, even though apparently has better connectivity than, when we looked at the ping Round Trip Times (RTTs) from SLAC it appeared that they were much better to
Thu Jan  8 09:16:21 PST 2004
1cottrell@flora04:~>ping -s
PING 56 data bytes
64 bytes from icmp_seq=0. time=570. ms
64 bytes from icmp_seq=1. time=566. ms
64 bytes from icmp_seq=437. time=588. ms
^C PING Statistics----
439 packets transmitted, 438 packets received, 0% packet loss
round-trip (ms)  min/avg/max = 551/588/647

1cottrell@flora04:~>ping -s
PING 56 data bytes
64 bytes from ( icmp_seq=0. time=320. ms
64 bytes from ( icmp_seq=1. time=303. ms
64 bytes from ( icmp_seq=383. time=252. ms
^C PING Statistics----
386 packets transmitted, 346 packets received, 10% packet loss
round-trip (ms)  min/avg/max = 249/292/372
It is seen that the RTT to is much better than that to, despite the latter's apparently better connectivity to the Internet. However the packet loss is lower for


routes from SLAC to the two host are quite different. goes via Stanford, CENIC, APAN, WIDE ( through, CERnet, to Zhejiang University, whereas goes via ESnet, ATT, ERX-CHINALINK ( through and through and through

The reverse routes (from Hangzhou to SLAC) are also different from each other as well as being asymmetric with the forward routes. goes via CERnet ( thru and thru ERX-CERNET-BKB) through STARTAP in Chicago ( through to ESnet. goes via CERnet to Cable & Wireless in LA and thence to PAIX in Palo Alto and on to ESnet and SLAC.

We used pingroute to see where the losses occurred on the forward routes. There appears to be about 2% packet loss on the end-to-end path between SLAC and It is difficult to see where this loss occurs since many routers along the path lose packets addressed to them. It is possible that the losses start occurring at the exchange between APAN and CERnet since from then onwards the losses are of the order of 2%. There appears to be < 0.1% loss on the route, even though some of the routers on the path lose pings directed at them.

More on link speeds

I recheck the report from CNNIC and find out that the 
exact bandwidth provisioned for interconnecting China
to the world is:

( By Sep. 30, 2003 )

CERNet -- U.S.  310Mbps
CERNet -- Japan  10Mbps
CERNet -- UK     45Mbps
ChinaNet -- U.S.  5935Mbps
ChinaNet -- Japan 1219Mbps 

( CERNet: China Education and Research Network, ZJU
located connects to it;
  ChinaNet: China Telecom, the bigest commercial
Network Service Provider of China, the
homepage for its division in HangZhou;

  above  data could be found at

Page owner: Jiri Navratil