Intermittent One-Way Audio to external extensions

[ryanswj]

Hello everyone!

I have been trying to battle this issue for the better part of today, but it seems that I have had no success.

I have been getting intermittent one-way audio on my 3CX setup - some calls I make to remote/external extensions work with bidirectional audio, but some only give one-way audio (I can't hear the caller but the caller can hear me).

On the other hand, all inbound calls have bidirectional audio.

I have opened all necessary ports (3CX Firewall scan passes with flying colors), but this issue is still happening.

I tried disabling/enabling STUN - no go.

UserID and Password are all correct + 3CX shows that it has successfully registered with my VoIP server.

Any ideas?

Thanks!

 

[leejor]

Are we talking multiple remote extensions at one location, or one extension each, at multiple remote locations?

Has this been an on-going issue from day one, or did it just begin all of a sudden?

Have you tried toggling the PBX delivers Audio setting, for each of the remote extensions to see if that has any effect?

 

[ryanswj]

Are we talking multiple remote extensions at one location, or one extension each, at multiple remote locations?

Has this been an on-going issue from day one, or did it just begin all of a sudden?

Have you tried toggling the PBX delivers Audio setting, for each of the remote extensions to see if that has any effect?

Hi leejor,

Thanks for your reply.

The extensions are all on the same network and in the same location physically.

This has been an on-going issue from day 1, with some calls having bidirectional audio and some having one-directional audio. I've tried toggling the setting but it has no effect.

An Asterisk server on my network works flawlessly though.

 

[lneblett]

I take your latest to mean that you have more than one extension at a remote location and however many extensions there are, they are all behind the same firewall/router. You did not mention the make of phone or remote router.

1. Did you follow the remote provisioning guides for your model of phone? The instructions can be found on the blog.
2. Assuming you have a fixed public IP, I have had the most luck turning STUN off in 3CX and the phones.
Ensuring that the router does not have any SIP ALG turned on.
Set the remote phones, if more than one, such that are not all using port 5060. Start the first at 5060, the second at 5061, etc.

Some routers are simply better at handling the traffic when a discrete port is used for each.

 

[cfive]

Hi Ryan,

Is your 3CX version current (latest)? Are the remotes using the tunnel proxy? I had this battle (your exact subject line) about a year ago, and it turned out to be a bug with the 3CX tunnel proxy that was fixed by patch and then permanently in subsequent release.