Here is what is going on. Connection is a point to point short haul data services using fibre. 100Mbit speed
We are only using it for voice. It has been used to extend the telephone network.
Service provider reports no problems with the circuit. The Cisco switches at either end are set to auto negotiation. When I copy files across this link simultaneously, one end is very slow. We get random issues of voice quality, one end can hear and the other not.
We also use call recording for call center agents. Right now all calls come in through the isdn30 at one location and transmitted over the shds link to the other location.when there are too many agents on the phone and the call queues increase customers can not hear the agents. This only happens to the agents at the other end who are across the shds. It does not happen to the agents who take calls at the main branch where all the equipment is.