High WAN RTT and OSPF

branfarm1 · ‎08-25-2008

Are there any special considerations when designing a WAN with OSPF that includes nodes that have RTT's around 200-300ms? Will that amount of delay cause issues?

Thanks,

--Brandon

Danilo Dy · ‎08-25-2008

Thus the RTT cause by congestion, unstable link, or distance?

The first two will have bad effect in OSPF.

I don't see any problem if the RTT is cause by the distance. However, large RTT may cause false timeouts and transmissions.

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/8594/27233/01210163.pdf?arnumber=1210163

branfarm1 · ‎08-25-2008

In this case the high RTT is due to distance, New York - Hong Kong. I'm designing a new network with an OSPF core across a VPLS mesh network. I'll have sites in London, Hong Kong, and New York. Do you think this will cause any issues?

Danilo Dy · ‎08-25-2008

I usually use BGP for long distance, and use OSPF for short distance.

branfarm1 · ‎08-26-2008

Since I have no working knowledge of BGP, I'm very very hesitant to try and implement that. I'm just curious if 200-300ms of latency between the two most distant nodes will cause any problems with OSPF.

Thanks again,

--Brandon