I’ve setup a simple Asterisk server using 3 Sipura SPA-841 SIP phones, and 2 POTS lines using 2 X100P FXO ZAP cards. We’re not doing any external VOIP.
When I use only the POTS lines, I have crystal clear sound everywhere (IVR, MOH, Voicemail, even if I dial in over one line and back out on the other).
However, when I use any of the SIP phones (SIP to SIP, ZAP to SIP, or SIP to ZAP), the connection is noisy with static and jitter, and echo is just horrible.
Everything I can find in the various FAQs would make me think that SIP to SIP on a quiet network should be the easiest setup. I can’t seem to find any settings to adjust either, because all of the echo cancellation stuff is for ZAP, which seems to be fine.
I’ve tried all kinds of stuff - changing cables, hubs, server nic, etc. I thought it might be something to do with my install, so I tried both a Xorcom Radpid install and a full-compile standard build. The Xorcom one actually seems silghtly better for some reason, but the problem is still there. I’m running this on an old PII/266, 384MB RAM, 2GB HDD - but I’m barely at 5% CPU and 40% RAM usage even when all lines are active and MOH is going.
Does anyone have any ideas? Perhaps something on the phones I can change? I’ve already upgraded to the latest firmware, and verified that I’m using the ulaw codec (should I force something else?).