Error Message with PBX Integration

[cjoseph23]

I am trying to configure a H323 gateway to work with a Avaya Merlin Magix PBX system. I have the IP side working fine but the Avaya side is unable to place outbound calls. Avaya side can receive inbound calls.

I have had the PBX vendor onsite and the Avaya is set for Primary-DMS100 and I have set the corresponding interface on the gateway as the same. I am getting the following error message when I place an outbound call

Channel unacceptable

IOS on gateway is

System image file is "flash:c3825-adventerprisek9-mz.124-22.T.bin"

If I reboot the Gateway outbound calling will work on the Avaya side for a while but later on in the day the error message pops up again. I don't want to keep rebooting the gateway to fix the issue.

Any Idea on what this message is telling me?

[cjoseph23]

Here is the output from my show isdn stat:

TANPG01#show isdn stat

Global ISDN Switchtype = primary-ni

ISDN Serial0/0/0:23 interface

dsl 0, interface ISDN Switchtype = primary-ni

Layer 1 Status:

ACTIVE

Layer 2 Status:

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

Layer 3 Status:

1 Active Layer 3 Call(s)

CCB:callid=147, sapi=0, ces=0, B-chan=1, calltype=VOICE

Active dsl 0 CCBs = 1

The Free Channel Mask: 0x807FFFFE

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

ISDN Serial0/1/0:23 interface

******* Network side configuration *******

dsl 1, interface ISDN Switchtype = primary-dms100

Layer 1 Status:

ACTIVE

Layer 2 Status:

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

Layer 3 Status:

1 Active Layer 3 Call(s)

CCB:callid=80D8, sapi=0, ces=0, B-chan=1, calltype=VOICE

Active dsl 1 CCBs = 1

The Free Channel Mask: 0x807FFFFE

Number of L2 Discards = 0, L2 Session ID = 3

Total Allocated ISDN CCBs = 2

TANPG01#

[Kenneth Mohammed]

Hello,

Im no expert on PBX integrations with IOS gateway, but the error you are receiving could be an issue with how the PBX and the gateway negotiate which b-channel to use. Under interface s0/1/0:23, try adding the command "isdn negotiate-bchan" and see if the behavior changes. Let us know.

Hope that helped, if so please rate.

[cjoseph23]

Thanks Kenneth,

I added the command to int ser0/1/0:23 but still I am getting the channel unnChannel unacceptable message in the isdn debug.

interface Serial0/1/0:23

description *** Connection to PBX ***

no ip address

encapsulation hdlc

isdn switch-type primary-dms100

isdn protocol-emulate network

isdn incoming-voice voice

isdn negotiate-bchan

no cdp enable

[Kenneth Mohammed]

On the Avaya side, can you verify which channel the outbound call is trying to use. According to the debug, the gateway appears to be trying to use channel 1 on the cisco side. I believe these 2 must match in order for the call to complete.

[cjoseph23]

I don't have access to the Avaya PBX. I would have to get the Avaya Vendor who supports that system onsite. I did change the bchan-order to descending in the int ser 0/1/0:23 also to see if that would make a difference but it did not.

I have opened a case with TAC and I will post there results to this case.

One thing they are saying is to reconfigure the Avaya to user switchtype primary-4ess but this would also require me to get the Avaya vendor onsite.

[Nicholas Matthews]

It's possible that the other side is configured for NFAS, or that we are.

Make sure that both sides are configured for FAS signaling.

hth,

nick

[cjoseph23]

I had the PBX vendor onsite and he changed the switchtype to primary-5ess. I changed the interface on the voice gateway to 5ess as well.

Nick - Not sure how to check for FAS signaling on the gateway so I wasn't able to verify that.

I did place a few dozen test calls and all is well so far. I will post more results after a couple of days in production.

cj

[cjoseph23]

Changing the PBX switchtype to Primary-5ess and the corresponding interface on the gateway to Primary-5ess resolved the issue I was having with outbound calling.