Cisco 7975G

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GTA_doum
Just Passing Thru
Posts: 4
Joined: 11/22/2009
SIP Device Name: Linksys SPA-942
ISP Name: Videotron
Computer OS: Windows 7

Cisco 7975G

Post by GTA_doum »

Hello,
I'm trying to connect my IP phone Cisco 7975G to my FreePhoneLine SIP account. I tested the phone and the xml file with another VoIP provider and it works. To connect to FreePhoneLine, I tried many different configuration but nothing works.
Any suggestions as to what configuration needs to be done to get the phone to connect to my SIP account? I have another phone, Linksys SPA942, and it connects to the FreePhoneLine without any issues. The Linksys is turned off while I try to connect the 7975G.
GTA_doum
Just Passing Thru
Posts: 4
Joined: 11/22/2009
SIP Device Name: Linksys SPA-942
ISP Name: Videotron
Computer OS: Windows 7

Re: Cisco 7975G

Post by GTA_doum »

Here is how I got it to work.
Because of a bug with UDP in this phone, it needs a transparent proxy to make the proper connection for it. So I program a reroute on UDP port 5080 in the router to redirect to itself, on which siproxd is running and listening on port 5080 (specified in its configuration file). The bug is that the phone sends out a request from a nat port (created by itself, not by the router) out to port 5080 (proxy port specified in the SEP.xml file), so the reply from the provider goes on the nat port given by the phone, but the phones refuses the port saying it is not valid! Siproxd always return the reply from the provider on its listening port, which works around the bug. This bug is not present with TCP, only with UDP. FreePhoneLine servers uses only UDP.

Since I use many VoIP providers, I used the firmware 8.5.4 on the phone, which permits to program a different proxy on each line button instead of dealing with the call manager, mandatory with firmware 9+.
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