How to baseline an IPsec (or whatever circuit) is performing accordingly

[news2010a]

Folks, do you know any tools people can use to perform file transfers over a certain circuit and come up with determination on whether circuit performance behaves according to typical expectation for a given circuit and latency? Thanks. In this case it is a VPN IPsec circuit that people are complaining it is slow.

[Joseph W. Doherty]

I find a TTCP tool sometimes works well since it performs much as any other TCP data flow should.

PS:

With IPSec, performance could be impacted by encryption perfomance and/or needless IP packet fragmentation.