Answer Supervision setup

[pbutros]

I'm having an issue after switching to a new local PRI carrier. Used to be with AT&T and now I'm having issues dialing numbers respog'd to AT&T. Did some testing and the Fujitsu 9600 is disconnecting when the remote carrier sends an "answer supervision" code back to the PBX usually when the call hits an auto-attendant. Is there anywhere where I can look to see how this is setup on the PBX? Thanks..

 

[ksphoneman]

Check the following service parameters,
DIS SVP,2,2 should be 0 (To Change, CHA SVP,2,X,DATA
DIS SVP 2,69 sould be 0
Check the Trunk Groups, should be in dialing group 0.
If AT&T before waere you set up for ISDN/PRI with call-by-call (Check DIS ISCBC)

 

[pbutros]

Thanks ksphoneman. Both SVP 2 and 69 show data 0

The iscbc is showing "none".

Here is some more insight. My former carrier supplied to local PRIs, both configured as Ni1 Custom 5eSS as the switch type. The 9600 has always been configured as DMS100 as the switch type for the trunk groups and it was working without a problem.

Do you know if the 9600 configured with DMS100 supports the 'answer supervision' protocol? Here is a snapshot of the CO trap of a failed call I tested. You can see where the 9600 gives a "Protocol Error #100 invalid info element".

Event 6 06/11/15 15:54:30 TEI 0
08 Q.931 Call Control Message
Call Reference Value Dest 4
M 03 Message Type PROGRESS
I 1E Progress Indicator Length = 2
8A Coding Standard CCITT
Location Beyond Interworking Network
81 Value Call is not End-to-End ISDN

Raw Hex Data
08 02 80 04 03 1E 02 8A 81
------------------------------------------------
Event 7 06/11/15 15:54:30 TEI 0
08 Q.931 Call Control Message
Call Reference Value Orig 4
M 7D Message Type STATUS
I 08 Cause Length = 3
80 Coding Standard CCITT
Location User
E4 Class Protocol Error
Value #100, Invalid Info Element Contents
Diagnostic Info Element ID
1E Info Element Progress Indicator
I 14 Call State Length = 1
03 Coding Standard CCITT
Value Outgoing Call Proceeding

Raw Hex Data
08 02 00 04 7D 08 03 80 E4 1E 14 01 03
------------------------------------------------

 

[telm59]

Be aware changing trunks to dialing group 0 will
disable any toll restriction. Besides that will not fix your problem.

 

[pbutros]

I'm at a loss folks. I am contemplating deleting the trunk group 139 which is 00001600 and set to NT DMS100 and then readding it as 5ESS. Do I have to delete trunk group 131 which is all the B-channels starting at 00001601?

Also, is there anything I need to lookout for when doing so? If I get in too deep, I can always bounce the PBX and have it revert to the prior config, right? I'm not planning on saving the config to disk until I am confortable that I did not make it any worse.

 

[ksphoneman]

The Q931 error "Missing mandatory IE" is sent by the carrier.
Likely running the NI2 protocol. The F9600 was never setup to send facility messages that are used by the NI2 standard.
The F9600 typically ignores any messages it does not interperet. The 5ess is very particular to information elements when compared to the NT DMS. NI2 is suppose to resolve these issues, yet the F9600 died before NI2 was built into the software.
To remove the trunks, DEL ISTRK,00001600 (D Channel EN)
All of the B channels will be removed also.
To rebuild ASS ISTRK, once for only the D channel, then run the command again to add the B channels.
TO display DIS ISINF.
Dialing group 0 on trunks does not disable Toll restriction.

 

[pbutros]

Thanks again ksphoneman. If the 9600 setup as DMS100 generally ignores commands it cannot interpret, any idea what else to look into? If DMS is more forgiving than 5ess, then wouldn't switching it to 5ess likely cause me more problems?

Is there a timing parameter that can possibly be increased in case the 9600 is looking for some protocol acknowledgement within a specific timeframe?

If you were in my shoes and you know the CO has provisioned the circuit as 5ESS, would you switch the tg to reflect 5ess as well? Thanks again...

 

[ksphoneman]

If the Central Office equipment is 5ess then use 5ess, if DMS use DMS ect. The protocol messages are different between switch types.

 

[pbutros]

I deleted the trunk and readded it as 5ESS and then added the B-channels. The only parameter I specified was the Slave on the D-channel and the DID-all on the B-channels. All other paramters I left blank. I saved the config and rebooted the switch. Now when I try and make a call it says "DENIED" on the LCD. Switching it back to DMS100 made it work again, so I do not know why the DENIED message. Is there something else I was supposed to do or can look at? I used the same Trunk Group numbers of 139 D-channel and 131 B-channels.

 

[ksphoneman]

I'm making this too hard, the Answer supervision problem, is it on incomming calls to your Auto Attendant, or another locations Auto Attendant.

 

[pbutros]

It strictly occurs when making outbound calls across our local PRI to toll free and local numbers where the receiving carrier sends the answer supervision protocol back to the Fujitsu. Thanks...