I can't find any information about what cisco telephones are supporting h.323 protocol.
There was a 7905G h.323 telephone, and now it is end of sales. Replacement is 6921 which is not supporting h323, or it is not written in the datasheet.
So question is simple - what cisco telephones support h.323?
Answer is - NO.
Cisco phones support it's proprietary SCCP to work with Cisco UCM/CME/UC500 and also support SIP to maintain the standard.
The oldie Cisco 7940/7960 might support the SIP firmwares to connect with Avaya IPO/CM but that's not officially supported by Cisco - so it's not worthy to discuss here.
ATA186/187 is an analog gateway which supports H.323 but this is to connect your analog phones and fax machines only. It has one RJ45 port to connect the Ethernet cable and at behind there is 4pin RJ11 - so forget the ATA186/187.
As Alex asked you - if you are looking for integration between Cisco UCM/CME/UC500 to Avaya IPO/CM by H.323 protocol then forget what I explained so far. Answer for that question is - YES.
1) You may be able to get the cisco phones working to an AVAYA as SIP, but not as H323 anymore.
2) Yes you can integrate a CME to an Avaya using H323.
Cisco has some great documentation re what they call interoperability on this link.
You need to have clue as to what the Cisco and the AVAYA devices are:-
Then say you wanted:-
Cisco CME to AVAYA S8700 using H323
You probably wonmt get the exact version numbers you want but the basic priciples will be very similar.
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