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Would an ISDN dial thru device be transparent to rest of this setup? 1

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garyb2008

Programmer
Apr 16, 2009
53
GB
Im working at a system with an Avaya IP Office 403 switch with 2 PRI cards connected to our telecoms 2 ISDN30 lines. Each cable has a tap, and the 2 cables from the tap go into a PC used for call recording (from Mercom).

We are thinking of placing an ISDN dial thru GSM gateway device on one of the lines, after the tap, trunk side.

To my mind this change will be transparant to the PC used for call recording, has anyone any experience doing this and agree disagree?
 
For example, could the nature of our telecoms ISDN30 line, for which our Mercom call recording unit was set up for, be subtley different to the nature of the ISDN30 provided by the dial thru device, causing the Mercom PC to no longer work?
 
This is a question for the Mercom providor and/or the Gateway providor really, but in general it would be transparent it just depends how well the dial through emulates the ISDN30. I have seen a call recorder/logger that when placed in line (also ISDN30) didn't emulate the lines correctly resulting in fialed calls out the IP office etc :)

ACSS (SME)
APSS (SME)

 
Who's selling Merocm in UK at the moment? <rhetoric>

The Audiolog used to be a passive ISDN tap, but I think they may now do some processing of the D channel messages to detect call termination (and call information).

However, as this is a IP403 = quite old now, I'd suspect that the Mercom uses a SMDR feed to terminate recording. Can you confirm this? There may be serial lead (Or possibly IP too) into the logger from a pc. You may also tell from the CTI module (on the bottom of the screen stack) you should see the SMDR events scrolling through witha tag of SMDR... It is so long since I last worked with a mercom (just after they migrated from Windows NT to Windows 2000 as a platform) so much of the detail is forgotten - but sadly the pain is indelibly etched on my soul!

As for the initial question - it depends, if the mercom is using D channel messaging to terminate the call, I'd be very careful about testing and ongoing monitoring but if it is a passive tap - you should be ok. I'd put the GSM box on the network side of the recorder though



Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.
 
Also in general I hate putting any device between the NTE and the system as it makes troubleshooting faults a finger pointing match half the time, you have two devices going in.....good luck with that :)

ACSS (SME)
APSS (SME)

 
Also in general I hate putting any device between the NTE and the system as it makes troubleshooting faults a finger pointing match half the time, you have two devices going in.....good luck with that

But it isn't 2 really - if the mercom is a passive tap!

And ETSI is ETSI....

Unless you are Kingston, of course :)

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.
 
Hi Matt

Due to the fact you say Mercom units have caused you incredible pain in the past, I can tell you are an expert in this field!!!

Our Mercom unit uses ISDN taps, and there is an ethernet connection from the switch as well where it can associate outgoing calls with the extensions they were placed from even though we withhold all CLIs. I do not think that it uses SMDR for this though.

What benifit would there be to placing the GSM gateway network side?
 
PS What is D channel messaging, why would it cause an issue?

Note, we need to record outbound calls, inbound doesnt matter so much.
 
Due to the fact you say Mercom units have caused you incredible pain in the past, I can tell you are an expert in this field!!!
Ex as in "has been" spert as in "drip under pressure" :)

I've done a bit of work with them in the past (5+ years)

The pain is caused by having to drive the length and breadth of the UK to support them

Our Mercom unit uses ISDN taps, and there is an ethernet connection from the switch as well where it can associate outgoing calls with the extensions they were placed from even though we withhold all CLIs

Thats good - you are using an out-of-band integration. Same ish principle as SMDR - the PABX tells the recorder to start (maybe - perhaps vox activated) and terminate recording. It also ties up which extension used which trunk to answer whcih call,so that the recorder can index it correctly. Is you link written by CTIgroup or versatilevoice by any chance? IIRC they did one for the index, and so possibly did one for IP Office too.

The key point to this is that the Mercom uses a high impedance tap to "sniff off" the ISDN calls and record them. It doesn't pass the information through teh recorder, it T's off it. i.e. it doesn't do any active work that affects the ISDN and PABX.

I'd be reasonably confident that, if the IPO can talk to the PSTN through the GSM gateway without issue, the Mercom won't affect it.

. I do not think that it uses SMDR for this though.
It probably doesn't!
What benefit would there be to placing the GSM gateway network side?

If you don't you'll miss any outbound calls that route to mobile through the GSM device!

PS What is D channel messaging, why would it cause an issue?

D-Channel messaging is the ISDN signalling used to pass call information from the PSTN to PABX and vice versa. That is Call setup & teardown, Dialled number info, Calling party number etc. Later versions of Mercom could decode this and use it to start & stop recordings. In general, CTI links to/from PABXs tend to be expensive items!

Can I be cheeky and ask who put the system in originally?

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.
 
What benefit would there be to placing the GSM gateway network side?

If you don't you'll miss any outbound calls that route to mobile through the GSM device!

I think were on the same page here, by putting the ISDN call thu device on the NTU side of the tap in, it means that all calls will go along the line Mercom taps into. If i put it network side in my sense of the meaning, mobile calls wouldnt go by it.

Business Systems put the Mercom system in. It has had sporadic crashes since instal, we enventually persuade them to replace it, and when they did they gave us an older Win2000 machine with a small C partition rather than the XP original. This meant our antivirus started causing problems, but even when we seemed to solve this, by reducing log info stores, it kept crashing though much less often. When they replaced the machine they didnt replace the ISDN card, maybe this is the issue, either ways, for a business critical device it turned out rather *shit*!

My boss told me he paid in the region of £15K for it over a few year period. It seems to me that an enterprising Asterisk programmer could do this for free. How much would you expect to pay for a tap in call recorder device recording 45 ISDN channels (2 lines)?
 
>My boss told me he paid in the region of £15K for it over a few year period

Sounds a bit on the high side - but not much. As obviously the lease costs are in there too.

I'm guessing that the database is no longer access!

>This meant our antivirus started causing problems

The only advice I can give you with AV and mercom is don't use on-access scanning. Only ever use a scheduled scan that is set to exclude the database and media files.

Did you get any manufacturer back up. The UK team *was* (this was before Verint bought them out so I don't know about now) pretty good.



Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.
 
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