2400 IMS/ICS and Carrier T-1 Incompatability..

[MrComputerTelephony]

Hello fellow NEC tech's.This is to give you a heads up when you switch T-1 carriers or your carrier changes there equipment.I have had an issue with my carrier since they have changed there switch from a Nortel DMS to a new Metaswitch.The problem with the Metaswitch is that it only sends digits over the T-1 in a DTMF type format instead of the standard DP(dial pulse)format.The 24DTR card on the 2400 only supports the DP type format for digits sent inbound.I have researched all the other local T-1 providers in my area,and they state that they can provide the digits inbound in the DP format.So make sure your carrier can support the DP type inbound digit signaling or you will be chasing your tale like me for 3 months...lol

 

[CDRMAN]

The 2400 supports both DTMF(Touch Tone) and DP on inbound calls - ARTD CDN 4 set to 3
that would be the standard setting for DP/PB

I could not imagine many carriers using dial pulse or a t-1 –

 

[MrComputerTelephony]

Well I know it suppose to work if CDN 4 is set to 3 in ARTD.But for some strange reason this switch was originally set up for immediate start with 4 digits coming in dial pulse(thats what the carrier says).The outbound is set for wink start,which works great.I'm going to change the cpu out when it comes in.I have worked on the 2400 for 15 years and never ran into this issue before.

 

[CDRMAN]

Strange it works using immediate start and DP on inbound.

you would think if it wink on the outbound it would be wink in bound.
Immediate start and dial pulse just sounds wrong

If you can perhaps use a fluke or a T-bird and monitor an incoming call -

Here are some switch settings i have used for years -
for B8ZS . Wink start circuits
i don’t have any switch settings for the new DTIC card - i have not had time to install and play with it

Good Luck

24 DTR
ESF B8ZS TIE/DID


SW 4D OR 10 4,5,8, ON
SW 39 OR 11 3,4 ON 3,4,6,8, ON ABAB SIGNALING
SW 38 OR 12 1,2,3,5,6,8, ON
SW 6C OR 13 ALL ON
SW 5D OR 14 2 ON
SW 25 OR 15 1 ON

 

[MrComputerTelephony]

Yes it is strange...One difference I have noticed is on the LED's for each channel.Before when an inbound call came in I would see it light up and flash on each digit coming in DP.But when I changed it to wink,I can see the card wink start the trunk but I never see the digit's.The carrier has brought there test set out and showed me the digits are coming in.Thanks for the switch settings.I will check them again.And thanks for your help CDRMAN.

 

[CDRMAN]

“But when I changed it to wink,I can see the card wink start the trunk “

You will not see the DTR flash after the wink- the incoming register should take care of the rest
Are calls now coming in ?/