HELLO & WELCOME

[Philip.Molgwey]

Hi,

I have been using voip at home now for about a year. I recently decided to put a voip phone system in my work place, it's a taxi office. I found a batch of used Linksys 941's on ebay which I successfully won and promptly received but this is where things go down hill!

Let me explain:

The office has 5 Linksys 941 phones installed and all of them are behaving rather strangely. The phones are online and successfully registered, but when called from a 'POTS' landline or 'GSM' mobile phone, the 941's do not ring most of the time (sometimes they do). They also do not display that the call is coming in, but the caller hears the phone is ringing.

When dialling internal (VOIP) extensions everything works all the time. Dialling out also works fine.

Any ideas anyone?

[WelshPaul]

This sounds very much like a NAT issue.

Does your VoIP provider offer a NAT proxy? They should! Get it added to your phones configuration settings.

Either that or can you try a different phone. Just to see if it is a hardware issue.

[Philip.Molgwey]

Thanks for the quick response Paul, unfortunately we do not have other hardware available. The only option would be to install a softphone on our pc and start using headsets.

I'm not aware of any changes on the nat configuration. We started to see this problem appearing around 3 weeks ago. Before that time everything seemed to be working fine.

[Philip.Molgwey]

I've just learned that we introduced an new Firewall in our office. It's an MS ISA server.
Would this be the likely cause an if so which port should be opened to get the phones to work properly?

[WelshPaul]

Who is the VoIP provider?

you would normally need to open ports 5004 to 5060