3 seconds pause when making external calls

Running * 1.6 on Ubuntu 8.04

I’m having an issue when a external call is placed the person answering cannot hear the caller for about 3 seconds. This isn’t on every call. Any ideas?

could be a number of issues.

1 - network latency in relaying the SIP 200 OK message.

2 - firewall issue. If you aren’t allowing data to come in on the RTP ports, and you are relying on your firewalls OUTBOUND/RELATED rules you may have some delay there. By default, Asterisk uses UDP 10000-20000 for RTP. You can try opening up the firewall to allow UDP on those ports to see if it fixes things.

Thanks very much for the replies. I think i’m starting to tie it to latency. It seems to happen most often when I get notifications that the cicso router is maxed… It’s also happening on all 24 channels too.

The asterisk server has it’s own T1 for voice so I don’t think is the firewall blocking any data. It connects to to comm box.

i also just assumed you were using SIP… if so, latency in call setup from the SIP messaging can certainly cause a delay.

Internally we are using SIP. Externally, we are PSTN using DTMF wink on all channels.