Affects of rate-limiting at the far end of links

[Sam Stickland <sam_ml () spacething org>]

Hi,

Just a quicky. We've got leased line out to a remote site that's pretty 
much at capacity for remote to local site traffic, and from time to time 
it appears to lock up for periods of 30 seconds or more.

Investigating it appears we outbound traffic shape, and ingress rate-limit 
at the 'local' end of the line, but nothing is done at the 'remote' end. 
The remote end is some 14ms away across a third party MPLS network.

Obviously we need to shape at the remote end, but the current behaviour 
intrigues me. Rate-limiting, while bad compared to shaping, in my 
experience doesn't lock out traffic for such long periods of time.

Could it be that buffers and flow-control over the 14ms third party leg 
are causing the rate-limiting leaky bucket to continue to overflow long 
after it's full?

Sam