09-18-2008 01:49 PM - edited 03-15-2019 01:23 PM
Hi I'm setting up a new voice gateway in UK. We have 3 BRI from BT. The problem is that I cannot pickup the inbound calls. Placing outbound calls isn't an issue.
We have 10 DID / DDI from BT.
The gateway is configured as a H.323 gw back to our CCM 4.2(3)
I can se the calls comming in when debuging isdn q931.
I've done this set-up in other European coutries before without any issues.
Is the BT ISDN BRI diffent from other operators?
Can some one se something faulty in the configuration?
Whats the next step to troubleshout?
09-18-2008 02:18 PM
09-18-2008 07:03 PM
What do you mean that you can't pick up inbound calls? Does the phone rings when a call is made? Anyway the things that you can check is the Inbound calls calling search space on your gateway configuration in your callmanager. Make sure it's set to a CSS that's allowed to reach the phones.
09-19-2008 01:35 AM
Hi,for BRI calls, BT normally sends 5 last digits, however BT can also modify the settings to send only 4 digits. If your extension number is 3 digits, then you have to created translation rules in the H323 gateway or you can set CCM to receive 5 digits and create the translation pattern in CUCM.
Hope this will help you.
Chandrasen
09-19-2008 03:20 AM
BT sends 6 digits. Looks like BT is doing something weird. I see the call comming in twich on the phone at the same time. That is also seen in the the ISDN q931 debug. It somes in on two BRIs. If I shutdown all BRI except one. It works fine. I rings and I can pick-up the call.
Any idea what's going on?
09-19-2008 03:32 AM
It looks like you have only 1 physical BRA line with 2 channels. You have most probably connected the 2 RJ-45 ports from the NT box to 2 BRA ports on the router. That is why you are seing 2 calls coming in when you run ISDN q931 debug. Just connect one cable from NT1 box to the BRA port. If you are expecting another BRA line, please look for another physical line.
Chandrasen
09-23-2008 07:20 AM
I had a similar issue, turned out to be a BT-ism.
I had to remove isdn static-tei 0 from each BRI interface. Something to do with how they configure multiple BRI. I had this issue when I tried to use BRI trunk, then had the config with static-tei then figured out had to remove it.
Specifically I have my BRI interfaces configured like:
interface BRI0/1/1
no ip address
isdn switch-type basic-net3
isdn tei-negotiation first-call
isdn point-to-point-setup
isdn incoming-voice voice
isdn calling-number .
!
09-20-2009 11:08 PM
Hi Craig,
I am having similar issues, I have x 2 BT ISDN BRI with 10 DDI numbers coming down them, when I configure isdn static tei 0 on both interfaces i can't pick calls up.
Can you confirm that after you applied the above configuration both ISDN interfaces worked ?
thanks
Rod
09-21-2009 02:23 AM
Rod, take a look at this post:
Posted by: ian.perry - Network Consultant, Comstor - Mar 25, 2009, 9:10am PST
If you have DDI numbering on an ISDN2, especially BT, you need a static TEI value of 0 (point-to-point)
If you have single number or MSN numbering, leave your TEI assignment as dynamic (point-to-multipoint).
Hope this helps,
Ian
09-21-2009 04:58 AM
Thanks Ian.
Do you have any working examples of say working BT BRI ISDN interface config, voice port config etc...
Thanks
Rod
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