Exceptions to Firewall - IP or MAC

I am looking for a way to specify certain machines to be allowed
access without the need for any form of authentication.  I  have some
voip phones going through the nocat box and they aren't able to sign
into a page.  For my current setup I have only 4 phones going across
the nocat box.

I tried to adapt the AllowedNetworks scripts at the bottom of
initialize.fw to allow those four IPs with no luck.

Has anyone done this workaround?

Any help greatly appreciated!