Weird Issue with AudioCodes MP-118

[jonathanjohnsn]

We are running 3CX with an Audiocodes MP-118 at a remote site, when they try to call headquarters, the autoattendant does not pick up. Not that it matters, but we have a NEC pbx at headquarters. This is only happening for the remote site. I can disconnect the MP-118 and plug in an analog phone, and the autoattendant picks up with no problem. But for some reason, everytime they call using 3CX, the autoattendant does not pick up. I know it has to be some line setting on the audiocodes, but there are way too many options to guess. Anyone got any ideas of what I can try?

 

[leejor]

Can they call any other number with no problems? Is this call going over the PSTN network? If so, and the call actually does go out on the network, then there should be no difference in a call placed by the gateway or any other set. Can you confirm that the Gateway is actually placing a call and the far end is ringing?

 

[jonathanjohnsn]

Call with Phone plugged directly into CO Line:
Autoattendant picks up.

Call through Audiocodes on same CO Line:
Autoattendant never picks up. But calling DID numbers at the same site, work with no problem.

 

[leejor]

have you confirmed that the gateway is reaching the correct location? Is there a way, in the other PBX, to confirm this? Do callers just hear continuous ringing? What means is this call getting to the other PBX, PSTN to VoIP, then PBX?

Could the other PBX be doing some sort of screening by caller ID?

 

[jonathanjohnsn]

Thanks again for your quick response.
The initial number we are dialing is a DID on the T1. I have dialed other direct to extension DIDs and they ring the phones with no problem.

Also, eventually after you let the phone ring 20+ times it goes to the operator.

 

[jonathanjohnsn]

I should also mention; that on the NEC voicemail side, I can see where I am calling in, and the status appears as if I was calling in and hearing everything I should, but all I hear on my end is ringing.

 

[leejor]

Without actually being there and looking at it myself, and not having worked on the NEC PBX, I can only make some assumption. I would say, it is incorrect digits being sent or interpreted at the receiving end, given that calls to their other DID numbers function correctly. I'm not sure if you have access to any sort of logs for the NEC PBX. Can you post an outbound call, one working and one that fails (just rings), from the 3CX logs?

 

[jonathanjohnsn]

leejor,
I will get the log information as soon as I get a chance. But the call never fails, it rings until it goes through to the operator. On the NEC you can see where the VM card picks up the call while it is ringing, but on my side it does nothing but ring. It then goes to the operator about the same time we have set as a timeout on the autoattendant. My guess is it doesn't connect the call until then, so it is something preventing the call from picking up...


Thx again,
Jonathan

 

[leejor]

I'm wondering if the NEC PBX is not sending an answer supervision on the calls to the auto attendant, but then does, once it goes to the operator (or sending something else not properly interpreted by the gateway/3CX)? Have you determined where the ringback tone is actually generated? Had an audio path been cut through as soon as the digits have been passed on to the NEC board? Is the gateway/3CX sending ringback until there is an answer?

Use of Wireshark, at the 3CX end may also show a difference between a working and non working call.