atcomsystems.ca/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Volume drop on magix

Ok, when you order a POTS line from an old line telephone company, they deliver a line that may meet their minimum standards. However if you order a “trunk” line, like a ground start trunk or a DID trunk, the circuit is “engineered”. Transmission levels are guaranteed and fall within a narrow range. Digital lines have no real loss.

When a trunk to trunk call is made using POTS lines, add the loss & noise of both circuits and your net loss is the result. You can have so much loss & noise callers can’t hear each other. (Example 2 pots lines with 20 db loss = trunk to trunk call of -40 db loss)

Switches find it difficult to add gain on these calls because of the unknown levels of the lines. Too much gain can be as evil as too little. It is too expensive to design switch hardware for such a seldom used application.

Change to “trunk class lines” or switch to digital lines and you won’t have the problem.

You hit the nail on the head guys. I even had Avaya tech support explain it to him, so now he is thinking about a PRI . Thanks again.