Echo on PTP Magix

[corner9]

I have 2 Magix R2 networked with a PTP T1. Location 1 is the main office and location 2 is a small office with 3 local loop-start co's. They are about 200 miles apart. The attendant at location 1 answers calls that come into the loop-start lines at location 2. There is a CVM at location 1,and most outbound calling is routed out of location 1 from location 2. Everything works great except that the calls that come into location 2 and route to the attendant at location 1 and are transferred back to location 2 have severe echo. The outside caller does not hear the echo. ONLY calls coming in the loop start and xfering back to location 2 lines have problems. I have swapped hardware like crazy. changed switch identifiers and even tried T1 tie vs PRI. But it still echoes.

 

[Dexman]

Speaking as a C.O. tech for an IXC, one possible source of the echo might be the total number of miles that a call going from location #1, across the PTP to location #2 and back across the PTP to location #1 would take.

Our company usually applies echo cancellation to circuits when it takes a test pattern at least 10mS to go from point A, to a hard loop at point Z and then back to point A.

The call being sent from location #1 to location #2 and back to location #1 is taking a path of, at least 600 miles. That might be enough to cause echo. I can't explain why only 1 person hears the echo though.

An end-to-end loop delay test on the PTP might be worth a try.