DSP/Ch problem, Cisco Router-PBX stop for making calls.

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Apr 21st, 2010
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Actually, I have for voice only the Cisco router connected to Avaya PBX with one E1 port for incoming/outgoing calls with g711ulaw code, they are working well, but I’m having problems with the DSP/Ch 0/1:1 when it’s blocked. I see that when this DSP/Ch is blocked the users start to have problems for making calls. On this moment the DSP/Ch 0/1:1 has one call that is not used anymore. I see this port blocked with different numbers.

Fort fixing it I need to reboot the E1 port.

Do you have any idea how I can block this DSP/Ch for testing?.

Router Name#sh voice call status

CallID     CID  ccVdb      Port             DSP/Ch  Called #   Codec    Dial-pee


0x1AC43    25B9 0x47DDB8E4 0/1/1:1.22       0/1:1   5001       g711ulaw  1/200

1 active call found

Thank you, best regards, Luis.

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David Hailey Wed, 04/21/2010 - 21:26
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Yes, you can busy out individual B channels on a PRI gateway from  within the CUCM Service Parameters.

Go to CCM Service Parameters  > Advanced > Clusterwide Parameters (Device - PRI and MGCP  Gateway) > Change  B-Channel Maintenance Status 1.

You can busy out  up to 5 channels at once as there are 5 configs for maintenance.

The  parameters are:


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This parameter allows Cisco CallManager to change individual  B-Channel maintenance status for PRI and CAS interfaces in real time for  troubleshooting.
Input Format:
Device Name = B-channel Maintenance Status
[email protected] = 0000 1111 0000 0000 0000 0001 (24 bits for  T1. Channel number begins with 1 to 24 from left to right. In the case  of PRI, the last bit specifies the D-Channel, which does not get  affected. In this example, the 5th through 8th B-Channels are out of  service.)
[email protected] = 0000 0000 0000  0000 0000 0000 1111 1111 (32 bits for E1. B-Channel number begins with 1  to 32 from left to right. The 16th channel specifies the D-Channel. The  last bit does not affect any channel. In this example, the 25th through  31st channels are marked out of service.)
The Device Name as specified in the Gateway Configuration page in Cisco  CallManager Administration MUST exactly match the gateway name that  this field specifies. To avoid any manual inputting mistake, copy the  Device Name from Cisco CallManager Administration and paste it into this  service parameter. "=" is mandatory and unique to distinguish the  Device Name and B-Channel Maintenance Status fields.
BCHANNEL MAINTENANCE STATUS = xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx
Where x can be:
0 -- In service
1 -- Graceful out of service (Change channel status until active call  ends if an active call exists on that channel.)
2 -- Forceful out of service (Tear down active call first; then, change  channel status immediately if an active call exists on that channel.)
Because values other than 0,1, or 2 are invalid, the system ignores  them. Make sure that the total number of 'x' is either 24 for T1 or 32  for E1. Any other invalid length or mismatch (for example, 24 for E1)  gets treated as error, and no action gets taken for that device.
SPACE: Optional.
The spaces between device name and "=", between '=' and BCHANNEL  MAINTENANCE STATUS, and between x and x, are all optional. You cannot  use any space inside the DEVICE NAME field.
PRI Specific:
To use this feature, the Enable status poll check box must be checked  on the PRI Gateway Configuration window. If it is not, you need to check  the check box, click Update, and reset the gateway for the service  parameter change to take effect.
lveraza2010 Thu, 04/22/2010 - 06:11
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Thanks !, but I´m not using CCM on this voice network. Do you have another idea ?.

David Hailey Thu, 04/22/2010 - 06:19
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Sorry, I don't know of a way to busy out a B-channel from IOS.  You may need to look into how granular you can be with Avaya in controlling the E1 channels.

Good luck.


ivelinivanov92 Thu, 04/29/2010 - 01:10
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I have not used this, but if you haven't also you can try to test "isdn busy b_channel" command under the corresponding serial interface configuration and see what happens.

thomuff Thu, 01/27/2011 - 10:56
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Would ds0 busyout command work?

controller t1 0/0/0
router(config-controller)#ds0 ?
  busyout  To busyout a range of ds0 CAS timeslots


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