General Questions

Hi everyone,

I'm experiencing some really strange VoIP quality problems that seem to only appear when running the full PC version of m0n0.  When I replace my m0n0 PC with a WRAP board, running 1.22, the call quality is fine.  When I run the full PC version of 1.22 (or 1.2b3), however, the person on the other end of a SIP call hears awful choppiness.  On the internal end of the call, the quality is always fine, regardless of who initiates the call.

I'm running Asterisk/Trixbox on a Dell PowerEdge, connecting via SIP to several different providers.  The Asterisk box is on a DMZ interface with a public IP.  When I use the WRAP board instead of the full PC version, the call quality is fine.  And when I move the Asterisk box to a different Internet connection (DSL) behind a Netopia router, the call quality is also fine.

I've tried version 1.2b3 and version 1.22 on the PC to match the version on the WRAP board.  I've also tried pfSense, and I've tried installing pfSense on two different PCs with different brands of NICs (3COM and Intel).  I've tried it with traffic shaping enabled and disabled, and with both standard dynamic NAT and advanced outbound NAT.  I never have problems registering to the ITSP or placing or receiving calls, but the PSTN end of the call sounds bad when behind m0n0wall or pfSense on the full PC version.

When I count to ten on a test call, the callee hears jitter and occasional missed digits (....5,si-i-i-ix,7,9,10).  With the WRAP board in place, the calls sound fine.

Does anyone know of differences between the embedded and full PC versions (or WRAP hardware) that might affect SIP voice quality like this?  Or a configuration setting that I should look for on this?

Thanks for any tips