this is a long shot, but it is based on my experience. I have played witht he 2600XM and most of them come with the H323 v.4 which, still has some unresolved issues with some other Telephony devices out there ( i am not sure who needs to catch up to whom). Based on your description, it could well be an IOS issue. I would recommand the following:
1) downgrade the 2600XM to IOS 12.2(5) for example, or any other IOS that doesn't have the new h323 v.4 (i belive anything prior to 12.2(11) will do). if the problem persists, then
2) turn on debug isdn q931 to see what you get. I will suspect something around the "bearer's capability not implemented" ISDN cause in the ReleaseComplete that the XM sends back to the PSTN switch.
if 1) solves your problem but you would like to use the rich features available with the v4 stack, then you might need to contact the ISP and CISCO to reconcile differences. I will guess cisco will tell you how to adjust some of the parameters on the XM's end to make it work.
Finally, let's know how you resolve this issue. I am pretty interested in the outcome.
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 ...
This document describe how DST changes and how time changes are
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