I have some problem with IP Fax (SIP).
I registering IP Fax to CUCM and success registered. But , i can't make a call. I trace to CUCM RTMT i give error message 488 .
Please, give me solution. I tried to configure after 1 weeks.
Make sure the codecs being sent from the Fax device are allowed in CUCM, the same goes for fax protocol (t38, Passthrough).
Please rate useful posts and mark answers as correct if applicable.