Recently I have been converting a lot of offices to VoIP. In addition to QoS & ACL there are other factors that could impact the phone line and quality of the call. One thing that particularly picky about how clean your phone line is FAX machines.
The location I was working on had Fiber network with awesome bandwidth. They had 8 Cisco ATA SPA122 adapters, 7 went into the phone system and 1 went to the fax machine. The ATA adapters were running the 1.21 firmware.
· The problem they were experiencing was some faxes going out will fail.
· No issues with incoming faxes at all.
· Faxes that go out to fax machines connected to a POTS will succeed
· Faxes that go out to some online fax services such as RingCentral, efax, etc will fail
· The failure occurs despite the type of fax machine you use
· You will hear the fax answer but it sounds like they fail to negotiate the type of protocol or something
Cisco’s 1.32 firmware sounded like they addressed the issue
CSCud58060 - ATA fails periodically while sending a v.34 fax in pass-through mode (Method=NSE) to a Cisco gateway.
But after contacting the VoIP vendor, they did not want to assist with upgrading the firmware. They were even hesitant with providing the admin password to the ATA (when ATA register to their SIP server, it changed the admin password).
Login into the ATA’s web interface as admin, if you plug in from the built in switch the default IP is 192.168.15.1. After logging in as admin you would need to go into Voice, click on Line 1, then scroll down to “Fax passthrough method” and set it to none.
Apply changes and this should fix any fax issues with other online fax services without updating your firmware.
