Call Forward to external number drops after one ring

Unanswered Question
Jan 7th, 2010
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I am having an intermittent issue with Call Forward to external numbers on the ISDN PRI (BT). When a call is forwarded the caller continues to hear ringing however the phone the call is forwarded to, only rings once and then disconnects the call.

I have had a look at debugs on the gateway and I can see a disconnect cause of 65, also the issue only seems to happen when the call comes in as 3.1kHz Audio and out as Speech. I have set the voice port to bearer Speech.

REASON: cause code = 65 - Bearer Capability Not Implemented. Indicates that the equipment sending this cause does not support the bearer capability requested (i.e., requesting 64kb data when only speech is supported).

Example: Inbound call

                Sending Complete
                Bearer Capability i = 0x9090A3
                                Standard = CCITT
                                Transfer Capability = 3.1kHz Audio
                                Transfer Mode = Circuit
                                Transfer Rate = 64 kbit/s
                Channel ID i = 0xA18381
                                Preferred, Channel 1
                Progress Ind i = 0x8483 - Origination address is non-ISDN 
                Calling Party Number i = 0x2183, '1628XXXXXX'
                                Plan:ISDN, Type:National
                Called Party Number i = 0x81, '79XXXX'
                                Plan:ISDN, Type:Unknown

Example: Forward

                Bearer Capability i = 0x8090A3
                                Standard = CCITT
                                Transfer Capability = Speech 
                                Transfer Mode = Circuit
                                Transfer Rate = 64 kbit/s
                Channel ID i = 0xA98382
                                Exclusive, Channel 2
                Calling Party Number i = 0x0081, '79XXXX'
                                Plan:Unknown, Type:Unknown
                Called Party Number i = 0x80, '127101628XXXXXX'
                                Plan:Unknown, Type:Unknown

I have asked the service provider but they say it's not them.

Your help would be much appreciated,


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brunonogaki Tue, 04/27/2010 - 11:11
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I am facing exactly the same issue in my CUCM 6.1.4-2000-2 cluster.

Have you fixed that?


lorrainet Thu, 04/29/2010 - 09:14
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The 'Wait for Far End H.245 Terminal Capability Set' on the CallManager Gateway Config page, which is normally checked be default, was unchecked. Checking this resolved the issue.


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