Bridged calls lost packets

Hello, everyone.

I have lost packets in bridged calls. In other situations (for example, when a subscriber enters an ivr), everything is okey. What can be the cause of packet loss? The trace shows that I receive good packets. Torn and jittered audio goes out of my FreePBX.

I have disabled the firewall. The computer has 2 network cards, one for the sip trunk, the other for other purposes (softphones etc.). The problem occurs with calls within the same sip trunk.

I dial external phones from the local channel without the “/n” switch, but packet loss can happen when I just dial an external number directly without the local channel.

You’re going to need a lot more debugging for us to be able to suggest where to look.

I’m going to start with “make sure you don’t have any “SIP Helpers” in any of your other network equipment” and then follow it up with “explain your two NIC setup to us so we might spot one of the dozens of typical network setup errors.”

Actual packet loss is almost always a network issue, and almost all calls in FreePBX are bridged, so we’re going to need you to provide some examples (from the logs, specifically) of what you are seeing and hearing.

What data should I provide about my NIC setup?
Also, might there be anything I can turn off on my asterisk machine that interferes with the network? Can audio quality or volume level lead to packet loss (for example, the asterisk itself turns off audio stream if audio level does not seem to bee high enough)?

In logs I see nothing special except occasional messages about exceptional long queue voice, when dialing through the local channel. Also, when I type pjsip show channelstats from within the asterisk console, I often see lost packets. I try make traces with tcpdump and analyze them with Wireshark, and they show good incoming traffic, but the outgoing traffic contains random jitter and lost packets.

If I examine channelstats, packet loss is shown when channels are bridged. First lost packets appear on the transmit side of one channel and then on the received side of the other channel of a particular bridge.

Also, I have found there are problems with NTPD (not starting, error : unable to bind to wildcard address - another process may be running - EXITING). Can this be a source of problem?

lsof -i :123

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