800 DID Module

[wgefit]

I used to have my Merlin Magix get all its incoming calls through a T1 connected to a 800 DID module. In the interest of saving money, I swapped out the T1 for POTS lines and plugged them all into the 412 TDL cards that are also in the system. Callers now have to enter an extension number at the auto-attendant, but it saves me a couple hundred bucks per month. So that's alright by me.

The POTS lines aren't actually POTS lines but just analog lines from an analog telephone adapter that connects to an IP PBX. Works remarkably well, actually.

But I am still interested in getting the DIDs to work eventually. I have seen all sorts of devices that serve as T1/E1 PRI-to-Ethernet bridges, but the problem is that I don't have an E1/T1 module in my Merlin Magix to make that work. Instead, what I need is something that does a similar thing with the 800 DID module.

The 800 DID module is still setup for the T1 that I used to have, and the trunks are all setup like this:

A Trk SS/PP Blk DiscTime Type ExpDig DelDig AddDig Signal InvDest
A 817 6/ 1 1 500ms Wink 3 0 TouchTone BkupExt
A 818 6/ 2 1 500ms Wink 3 0 TouchTone BkupExt
A 819 6/ 3 1 500ms Wink 3 0 TouchTone BkupExt
A 820 6/ 4 1 500ms Wink 3 0 TouchTone BkupExt
A 821 6/ 5 2 500ms Wink 3 0 TouchTone BkupExt
A 822 6/ 6 2 500ms Wink 3 0 TouchTone BkupExt
A 823 6/ 7 2 500ms Wink 3 0 TouchTone BkupExt
A 824 6/ 8 2 500ms Wink 3 0 TouchTone BkupExt

Any of you know of a VoIP device out there that can fake the T1 that I used to have and give the 800 DID module what it is looking for? This is obviously not just an analog phone line, but four, single-channel digital lines. (I only ever used the first four trunks on the 800 DID module.) Seems like it might be a weird setup that is rare enough that nobody else has ever tried this before.

 

[SYQUEST]

Who is the service provider for the DID service, and do they provide analogue DID trunks?

....JIM....

 

[wgefit]

The DID provider is my VoIP provider, Bandwidth.com, and they don't do analog DID trunks. What I need is piece of hardware that can go between my IP PBX and the 800 DID module on the Merlin Magix.

 

[merlinman]

Well, if you are willing to spend that kind of money, you may as well throw a 100D T1 module in there and be done with it.

But, that's just my opinion based on the fact that I don't know of any such devise as you are looking for.

If there is such a thing, your provider should know about it.

http://home.comcast.net/~merlinman

 

[dagwoodsystems]

First, you should know that the 800 DID card is analog. I throw that in there because you continue to mention a T1 in the mix, which really has nothing to do with it. To interface an 800 DID module, you MUST have analog signalling and be able to both accept and generate 48 volts of DC current for the wink. Digital circuit have an analogous way of doing that with bits, but analog circuits need voltage for signalling.

In your previous setup, you somehow had the T1 converted into such a circuit...perhaps through a channelbank.

You don't mention what external IP box this is. But whatever it is, research whether it can provide 2-wire E&M Wink-Start signalling. If this is an Asterisk with Dialogic boards or whatever, the answer already is yes.

Tim Alberstein

http://www.dagwoodsystems.com

 

[wgefit]

Thanks, Tim. That actually makes alot of sense now that you say it. Buying an analog telephone adapter was cheaper than getting the TDM cards for Asterisk, but it looks like that is exactly what I should have bought. Fortunately, an ATA is actually a pretty useful thing to have. I will probably just end up using it for fax lines from here on out. Cheers.

 

[dagwoodsystems]

In case this thread ever gets looked up, I should clarify:

1. Only with 4-wire analog E&M tie lines would you need to worry about the PBX providing 48vdc (for outbound calls).

2. Circuits terminating on an 800 DID card rely on a momentary polarity reversal from the telco to indicate the wink. Note that calls are strictly inbound only (distinctly different from two-way, 2-wire E&M wink circuits).

Sorry for the minutia, but I wasn't going to sleep after giving you half truths in my last post...even if the basics about analog circuits hold true.

Tim Alberstein

http://www.dagwoodsystems.com