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).
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Make sure the bandwidth is allocated properly between the locations assigned to the devices.