Voice quality degradation with IOS FW

[rarick123]

I'm running into a situation where the IOS firewall (with or without URL filtering) is causing voice quality on SIP calls to degrade... one way audio, echoes, etc. I tried specifically not inspecting SIP, thinking it was eating too much processor, but that didn't fix it. Would switching to ZFW and putting my Serial interface and Loopback (source for VoIP calls) in the same zone be a better idea?

[hadbou]

Refer to the following urls which will be of great help to you in troubleshooting the ios firewall and configuring Zone based firewall::

http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a0080094112.shtml

http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a00808bc994.shtml