A small number of issues have been reported to Avaya involving echo heard from IP Telephones involving calls from PRI-24 trunks. In these installations instances of echo may be heard at the IP Telephone.
The recommended solution is to adjust the PRI transmit gain by -5dB. This can be changed from Manager by selecting the PRI line channels tab, highlighting all channels and selecting the Edit option. For the Tx Gain, select the -5.0dB option on the pulldown menu. Select OK to leave edit mode and OK to save the line settings, and then save the new configuration back to the unit.