Do you have also configured "isdn overlap receiving?
If so the following Bug describes our problem. The bug status is resolved though no workaround and no fixed version is mentioned. No idea how cisco thinks that it is resolved, do they think overlap receiving is not needed, I don´t konow?!
CSCed95175 Bug Details
Symptom: When Overlap receiving is configured on ISDN and the destination is setup to
call forward all, we do not send call proceeding, alerting or connect back to PSTN, causing
the call to be disconnected due to Recovery on Timer Expiry
Conditions: Seen only when overlap receiving is configured.
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The short answer is that you don't.... That isn't entirely true while at
the same time it kind of is, but for the most part you don't configure
the softkeys. You enable or disable them via TCL. Here is the long
answer. Be sure to read the whole thing or e...
Topology: IP Phone > Switches > Microsoft NPS setup to forward 802.1x
proxy to > ISE 2.1 patch 3 Authentication: EAP-TLS using Cisco MIC SANs
Phone Models 802.1X support? 802.1x flavor Addtl Comment EAP-MD5 EAP-TLS
Cisco 3905 Y Y N Cisco 6911 Y Y N Cisco ...