No remote audio

Tags: #<Tag:0x00007f24bd9b7998>

(United States) #1

I am having some trouble with FreePBX. I have the SIP ports port forwarded, as well as the RTP 10000-20000 ports open UDP, and forwarded to the server. I am able to register the phones, but I do not hear any audio from either end. I have turned off windows firewall on the server it is running on, and the PBX has a direct connection to the network. I am not sure why I cannot get audio to go trough either way on this one. Here are the ports here shown in my router


sngrep is your friend here, It can quickly reveal where your network is mis-configured.

(United States) #3

Hi there, would you be so kind and show me how to use that? This is the first time that I have seen this tool


It has a man page, before reading that though, you will need to familiarize yourself with how SIP negotiates SDP sessions.

sngrep will likely show your internal INVITES working in your LAN but when external INVITES negotiate a SDP connection, how your router is not forwarding correctly

(United States) #5

I made a test call with that open to a remote extension and here is what I saw


Now you have to ‘drill down’ (by successively pressing the enter key on ‘interesting stuff’ and pressing Q to go backwards)

( I thought I told you it had a man page already :slight_smile: )

(United States) #7

sorry I took that before you mentioned that.

(United States) #8

Looks like it is a PBX related issue. I have started a new install and registered a remote endpoint to and there is audio oddly enough.


You would have to expand on that as it does not compute, how is it any way a ‘PBX related issue’ and not a @Whacka related issue

Are you saying " one system works but another one doesn’t using exactly the same method" ?

(United States) #10

It’s possible that it is a @whacka issue, as my name suggests I am a bit of a whack. but ‘one system works but another one doesn’t using exactly the same method’ is exactly correct. I will probably just rebuild my PBX unless there is a really simple solution to this.


Go for it, there obviously can be no rational solution, simple or really complicated, for any un-isolated and purely anecdotal “problem”. I would suspect an outbreak of PEBKAC