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Cisco Bug: CSCun33456 - CUCM reject incoming requets mode form H323 Gateway

Last Modified

May 25, 2020

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases


Description (partial)

Outgoing Pass-through fax call will fail over H323 gateway.

FAX -- ATA --- CUCM --H323 -- VG--SIP -- ITSP

All the place we configured pass-through (Protocol Based)

After initial call Gateway send RequetsMode(Audio G711Alaw) to CUCM and CUCM reject this Request. Hence switchover doesn't happen.

This is valid for a call falling back from T38 to Audio as well.
If a call sets up as Audio, Switchovers to t38 but fax does not work, gateway will try to switchback to audio mode and will be rejected by CUCM.

Currently it is working as designed.

Whenever an incoming audio mode RM comes to CUCM, it reject. CUCM allows only Data or T.38 Request Mode.
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