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AT Command set on A 2911 PVDM2 Modem


Hi all,

I'm having issues trying to dial into the network via ISDN.  Setup is

1.     Users dial in via ISDN PRI/BRI or POTS.

2.     Users using PRI/BRI don't have a problem

3.     Users using the POTS modem way are getting disconnected after approx 5 seconds

4.     Debug shows a disconnect cause '0xF Loss of DTR'

5.     The running config is exactly the same as that of a working 3725 (out of support that's why we're moving to 2911)

6.     Only difference is in the AT Command set modem settings where registry S25 is set to 5 on the 2911 but 0 on the 3725

Problem I have is that when I change the registry setting on the PVDM it is accepted, but as soon as I disconnect my reverse telnet session from the line, it reverts back to the default of 5.  How do I save the registry S25 setting so that it won't revert back?       

I have changed the settings then carried out a at&w - which made no difference.  I have also carried out the at&y0 after changing the settings but again, made no difference.  I can't find anything on this page Link that shows how to save the settings (but then again, it could be I can't see the wood for the trees).          

Any help/pointers would be greatly appreciated.


1 Reply 1


I have been chasing up the wrong tree with the modem registry settings,

refer to this page

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