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External/Internal Calls don't work on New 2901 Router

Cisco 2901 VoIP router with PVDM3-16= module, PVDM3-64= module, VWIC3-1MFT-T1/E1 card.  IOS 15.1(4)M4

We are replacing our 1760 router with this new 2901 router and the configs are the same.  When we dial out we here a busy tone and sometimes when dialing in there is also a busy tone.  See attached files.  I am not sure what is wrong with the config.

Everyone's tags (6)
Hall of Fame Master

Re: External/Internal Calls don't work on New 2901 Router

Check "shpw isdn status", and "debug isdn q931" with "term mon".      


External/Internal Calls don't work on New 2901 Router

I get this with show isdn status:

Global ISDN Switchtype = primary-ni

ISDN Serial0/0/0:23 interface

        dsl 0, interface ISDN Switchtype = primary-ni

    Layer 1 Status:


    Layer 2 Status:

        TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

    Layer 3 Status:

        0 Active Layer 3 Call(s)

    Active dsl 0 CCBs = 0

    The Free Channel Mask:  0x807FFFFF

    Number of L2 Discards = 0, L2 Session ID = 1

    Total Allocated ISDN CCBs = 0

Cisco Employee

External/Internal Calls don't work on New 2901 Router

Hi ryasuda26,

You mentioned external and internal (ip phone to ip phone?) calls arent working. Looking at the config, I see the 2901 is configured for MGCP and SRST. Let's break down the problem further:

1>     Need clarity on whether you can call IP phone to IP phone (Internal calls).

2>     Outputs needed from 2901: "show ccm-manager", "show mgcp endpoint"

3>     "debug isdn q931" from the 2901 for an outbound and inbound PSTN call.

4>     For the same test calls, collect detailed CUCM traces from all nodes in the cluster with the following trace settings applied to all nodes:

Cisco CallManager Trace Fields

Enable CDR Trace

Enable PRI Trace        

Enable All Phone Device Trace

Enable ISDN Translation Trace        

Enable MTP Trace

Enable All GateWay Trace

Enable Miscellaneous Trace        

Enable Forward & Miscellaneous Trace

Enable MGCP Trace   

Enable Music On Hold Trace        

Enable Media Resource Manager Trace

Enable Annunciator Trace

Enable SoftKey Trace

Enable Route or Hunt List Trace

5>     Call details like calling party number, called party number, timestamp of the test calls, IP address and MAC address of IP Phone, etc.

Once gathered, please upload here and I will take a look.




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