Skype video / audio breaking up

[#1]

Aaah.  That's internal network.  Were you still seeing a problem?  If so, it suggests an issue with your network or one of the machines.

[#2]

There was no problem when running skype between 2 machines internally. I had wrongly assumed that it would still go out to skype servers and back in again.
The problem just seems to be with the wired desktop which shows good upload / download speeds on test but struggles with Skype