atcomsystems.ca/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems Audible ringback on MICS with PRI

I have two Norstar MICS with 5.0 software that we were converting from T-1 to PRI. When we cut over to PRI, calls would go thru but the calling party (calling into the MICS) did not have audible ringback. We have worked this problem with Qwest tier 3 support and they are quoting me the Bellcore standard SR4994 - ISDN CPE guidelines section 5.1 "Audible ring tone shall be provided by terminal CPE." There is not a setting on the MICS that controls this. The Qwest is providing the circuit from a 5ESS. This is occurring on 2 different MICS coming from 2 Different central offices (both Qwest, both cut the same day, both probably built at the same time by the same person since they were on the same order.) Qwest is insisting that this is being caused by the MICS. They have put a protocol analyzer on the circuit and captured a call both thru the switch and with the switch removed. both sessions came back the "CPE" was not sending the ringback tone signaling.

I am at a loss. I have talked to a number of other techs and no one has ever had this problem on a Norstar. Any help would be appreciated.

Thanks,
Barb

Barb,
In follow up to my PM, your post indicates that your provider's policy requires them to provision your PRI to receive the ringtone from your local system(s). I'm not very familiar with Norstar/MICS systems, however, if your MICS does not control the providing of ringtone back to the provider, let's see if other members may be able to add their input based on their MICS experience, and how they adressed any problems similar to yours. Please understand that I wish to refrain from discussing 5E translations (even though the translations do provide for ringtone control and treatment) in respect of your provider's policy, not that I disagree or agree with them.

Mike,
I understand your hesitancy. I was hoping you could tell me somewhere either in the trunk group or the Pri provisioning where there might be a parameter they could change to allow ringback.

Barb

PM sent

Hi Barb I have several customers with pri's on mics and myself i have never had to ajust anything for when calling into the mics
i have pri's from different providers as well,
also i have never heard thru the grapevines about
this problem but maybe here in canada we have different protocols.
Also when i have to call our telco providers,
here they always come with the answer looks good on our side,its gotta be your equipment
hope this helps you

Sentrex1- Teir III tech support with the provider has been working with me. They have come out to the site and monitored the circuit with a protocol analyzer and captured a session (live call) and they say that they are not seeing the Norstar send back the signaling information to generate ringback tone. They have quoted Belcore standard SR4994 ISDN CPE Guidelines Section 5.1 "Audible ringtone shall be provided by the terminating CPE." They said they have looked at all the provisioning and can't find a problem on their end.

I was hoping someone else may have had a problem like this and could give me some insight. Also if anyone is familiar with the 5ESS programming and or 5E and Norstar that they may be able to point me in the right direction when speaking with my provider. I do not know alot about the 5E and I may be using the wrong terminology.

Barb,
Have them check for any special "BRCS" features assigned in their 5E "Recent Change/5.4 views", to make sure that the BRCS features on the the "no-ringtone" PRI match the BRCS features assigned to your other customer's good PRI.

Mike,
I have them checking. I asked them for a printout of the trunk group configuration but they said it was proprietary.

Are the PRI's set for NI2?

Norstar is set up as:
Hardware=PRI - Lines 001-023 Protocol=NI2 NSF ext=None
Bchan seq=Descend
CBC Routing= FX=None 800=None
CO Fail=TIA 547A
IF levels=ISDN
Framing=ESF
Internal CSU=on
CSU line buildout=0
Line coding=B8ZS
Clock Source= Primary

Also have made sure all 23 lines are provisioned
Under lines is set up PRI-A no prime set.

All calls both inbound and outbound complete. The problem is when a caller calls in, they will not hear audible ringback tone. They will hear silence and all of a sudden the customer (norstar) will answer the call. Most people calling the customer will hang up and try again because they think the call is not going thru since they are not hearing ringback tones.