We've got a situation with 2 B179s connected to an Avaya ERS3534GT-POE+ switch, manually set to tag packets to VLAN 43; PBX is a 9.1.7 IPO500v2. They become unresponsive from time to time for no apparent reason, but a reboot brings them back. Firmware version was 2.4.1.5 but I've just upgraded to 2.4.2.0 to see if things improve. Someone else mentioned that they saw the same issue and a downgrade to 2.3.2.0 resolved it.
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Calgary Telephone Systems, Avaya LG Asterisk (FreePBX) VOIP & TDM
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Calgary Telephone Systems, Avaya LG Asterisk (FreePBX) VOIP & TDM