My asterisk is on a remote site behind an NAT router.
I have two extensions 3001 (192.168.7.32) and 3008 (192.168.7.93) on the same LAN in a separate site with external IP 176.156.223.236. These two extensions are registered to the asterisk.
My network works pretty well. These two extensions can call in and out, including via a SPA 3000 to the POTS world.
However, I now find that extensions 3001 and 3008 cannot hear one another. It’s odd because the log says “media will flow directly between them” and both end points are the local LAN IP addresses as shown below:
== Using SIP RTP CoS mark 5
> 0x16b8118 -- Strict RTP learning after remote address set to: 192.168.7.32:51376
-- Executing [3008@from-internal:1] Answer("SIP/3001-000000ab", "") in new stack
> 0x16b8118 -- Strict RTP qualifying stream type: audio
> 0x16b8118 -- Strict RTP switching source address to 176.156.223.236:51376
-- Executing [3008@from-internal:2] Dial("SIP/3001-000000ab", "SIP/3008,300") in new stack
== Using SIP RTP CoS mark 5
-- Called SIP/3008
-- SIP/3008-000000ac is ringing
> 0x1bfdab0 -- Strict RTP learning after remote address set to: 192.168.7.93:43554
-- SIP/3008-000000ac answered SIP/3001-000000ab
-- Channel SIP/3008-000000ac joined 'simple_bridge' basic-bridge <faa8a1ff-d74d-4b31-8f32-6123b148675b>
-- Channel SIP/3001-000000ab joined 'simple_bridge' basic-bridge <faa8a1ff-d74d-4b31-8f32-6123b148675b>
> Bridge faa8a1ff-d74d-4b31-8f32-6123b148675b: switching from simple_bridge technology to native_rtp
> Remotely bridged 'SIP/3001-000000ab' and 'SIP/3008-000000ac' - media will flow directly between them
> 0x1bfdab0 -- Strict RTP qualifying stream type: audio
> 0x1bfdab0 -- Strict RTP learning after remote address set to: 192.168.7.93:43554
> 0x16b8118 -- Strict RTP learning after remote address set to: 192.168.7.32:51376
What could be the cause of the problem? Is the problem local to something in the 192.168.7.x LAN or could it be due to configuration in sip.conf?