Topic: IP Phone and 2nd Site Cant hear caller but caller can hear them

[kennyehresman]

So we are in the process of bringing our 2nd site online and in the process of adding some IP Phones, we are experiencing problems where the caller can hear us, but we cannot hear them. When this happens it usually happens to all the IP phones. Now when I reboot the IP phones they start working fine. I have checked all the settings and this is just random when it happens. We can go weeks with no problems and then all of sudden there not working, and i have have seen if we don't do anything and let them sit long enough they will start working again.  Recently this has happen with the 2nd phone system.

The main site has a 7200 with all our trunk lines. Our 2nd site has a 7100 that connects to our 7200 through MGI and SPNet on the same network. When we hit 9 on the 7100 system it picks up a line from the 7200 and calls the number. Our 2nd site has a few IP phones that are linked to the 7200 for the receptionist and managers. So when the IP phones that are connected to the 7200 are being used randomly we have had problems where the caller can hear us but we can not hear them. When this happens its all IP phones, but when we power cycle the phone or just wait it out they start to work magically. Any help would be appreciated.

What am I missing??

[matherton]

Hi Kenny, its not as simple as 'try this or try that' when you're talking about having 2 sites networked using SPNET and combining IP phones on one site but connected to the other.  On the surface the systems can do all of this - and they do it quite well, but the missing components are your network.  It sounds on the surface that your network router may be closing some ports (even though they show open in programming), and a reboot of the phone re-opens them when it logs into the pbx.  I would off the top do a wireshark test when the voip phone has 1 way audio, and see what the router is doing with the voice packets.  Start there - that will probably be pretty telling - one way audio is all about packets being blocked or re-directed by the network gear. (Sonicwall are an example of one that closes ports unless its professionally set up)
Start with the wireshark test.