Telco discussions

I'm evaluating the new cisco 2524 with internal CSU/DSU, and it looks
like the default is ESF/B8ZS on this box too. Maybe there's hope for
the vendors catching up with reality on this front afterall.

Ditto with the equipment I use from LARSCOM. Defaults are D4/AMI/RS449.
The hardware itself seems just about bulletproof, however. Although
the telcos seem to have never heard of it.

Anyone have experience mixing different vendor CSU/DSUs and getting
things like remote loopback to work?

I don't recall having problems on T1's. I'm told that mixing vendor
equipment on IMUXed multiple T1's is a recipe for disaster and therefore
haven't tried to do it.