Prevent ISDB calls from PRI interface

Unanswered Question

I have a Cisco 3745 router with 48Digital Modems and 2 x E1 interfaces E 1/0 and E 1/1

i have configured for 1 Pri Circuit to Dail out (E 1/0) and the other to dialin (E 1/1).

I have configured the lines 65 - 94 for dialout and dialin line 97-117 . However I  have noticed that

E 1/1 will make calls out the dialout lines when the E 1/0 is busy. I am looking to prevent this.

Any Suggestions would be greatly appreciated.


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paolo bevilacqua Wed, 12/16/2009 - 13:24
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Show config.

paolo bevilacqua Thu, 12/17/2009 - 03:00
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Split the lines config in two groups, one has transport input none, the other transport output none, and vice-versa

One has rotary, the other has not. You can also create a modedmcap that disiables autoanswer for the outgoing lines.

Unrelated - You do not need the group async interface.

Thanks for Assistance


When the PRI dial out circuit is removed from E1 1/0 and Dial in circuit remains in E1 1/1. The server telnets to rotary group 1 which is associated with E 1 1/0 DM modem dialout lines and a call is connected from Ser 1/1:30 and then Ser 1/1:29.

So i need to prevent the E1 1/1 from calling out, Note these channes are not assocaited with any modem as there are only 48 modems. If I remove there channells from service.

many Thanks


paolo bevilacqua Thu, 12/17/2009 - 12:35
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That is what I'm saying, have rotary only on the lines where it is necessary.

Modems are dynamically allocated, so there will be always one free unless all are taken already.

I see this command would probable be sufficient, however it appears to only be within the AS Series and not the 3745 router platform.

are you aware of a similar command for the 3745 router.


To specify a particular T1 or  E1 controller through which to dial out, use the modem  dialout controller

command in line configuration  mode. To disable the command, use the no form of this  command.

modem  dialout controller {e1 | t1} controller-list

no modem  dialout controller

Syntax  Description

Command  Default All T1 and E1 controllers are  used for dial out.

Command  Modes Line  configuration

Command  History

Usage  Guidelines This command is only supported  on the Cisco AS5300, Cisco AS5350, Cisco AS5400,  and

Cisco AS5800


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