point-to-point T1

[coniglio]

i am in way over my head with this one. I have an AT&T point to point T1 which has the 24th channel set to DCH-1. A) does this mean D-channel? B) is this where the caller ID info comes from? this is an office that we dial via CDP. C) another vendor is saying what we currently have is NOT a PRI circuit but something else. Is there any way for me to verify either way what it is exactly? As must be painfully obvious to whoever is reading this, i have basically no real idea of how many different types of T1s there are. Thank you for your help.

 

[phonejack99]

If the 24th channel is set up as a DCH then this is a PRI.

The D-channel does controll the signalling; call setup, tear down, name display, etc.

Why does vendor think otherwise?

 

[coniglio]

i do not know. The new vendor is Con Ed and they say that what we have is actually an Acculink (whatever that means). i have no idea how or why they think that but whatever an ACCULINK is, could that be what we have? or if channel 24 is D-channel then is it DEFINITELY a PRI? Thank you. PS: if we're calling each other via CDP then do we even need caller ID? Apparently we got it that way because our VOICEMAILS are networked. If we had no voicemail would we still need caller ID on our circuit if we use CDP? You guys are the best!

 

[Nahart]

Acculinc is just a product name for their version of PRI. Primary Rate Interface is a standard. Most Telco's and Carriers call their version of PRI by a catchy name.

CDP only tells your switch where to send a call. Incoming call info will tell your meridian mail who's mailbox the call is for. I am assuming you have 2 pbx's tied together and using one voicemail system.

 

[coniglio]

so Primary Rate Interface and caller ID go hand-in-hand? if you want caller ID on a point-to-point T1 circuit you MUST order the circuit as PRI? By the way, we have TWO separate voicemails and the PBXs are tied together via CDP but that's it.

 

[Nahart]

Before PRI, the only way to get call information on a T1 was with a external special circuit from the C.O. to your PBX (very expensive.)
With ISDN, all that call information, including the call setup information is handled by the D channel. By the way, Caller ID is sent over an analog line using FSK tones of 1200/2300 hz by the C.O. That info is sent between the first and second ring of the incoming call and received by a Caller ID box or set.
A digital circuit such as PRI will send a data stream with call info using the D Channel. It will present ANI (automatic number identification.)

 

[rachelle]

You have gotten some very thorough answers from everyone above. My only other suggestion is, to alleviate all doubt in your mind as to what you have or don't have, contact AT&T and verify the type of circuit that they are providing you. That is a simple 800# call and they should be able to set you straight in no time.

From everything that has been posted, it does sound like you have an ISDN/PRI circuit already and ConEd may be trying to upsell you to their service.

rlc

no matter where you go, there you are.

 

[coniglio]

i have since verified that we definitely have a PRI as our point-to-point circuit. We have two separate voicemail systems that are networked together. the remote offices' exts are programmed as CDP so that I dial access code plus 4-digit number (not DIDs). I needed the access code because remote loc.'s primary DNs conflict with our rollovers. Another vendor came in yesterday saying we absolutely did not need a PRI circuit to see the name of the person we are calling at remote office via the tieline. Is this true?

 

[StoneColdphoneman]

Sounds like that vender of yours is smoking something but it’s probably not cigarettes, any way you do need D-ch for names and message waiting light to work, if they told you that you don’t need PRI then ask them how they will accomplish that with out D-ch.

 

[jgideon]

one little thing to factor in--if it is a 'point to point' T1 (i.e. going between your PBX's and NOT connecting to the public network), then really it is just a plain T1 configred as b8zs/esf framing/coding. The carrier doesn't need to know what is running on it, just that you want a point to point with that framing/coding. You could run any kind of trunks on that P2P circuit, but PRI gives you better communication. (PRI requires b8zs/esf, while plain TIE trunks could be b8zs/esf or other combinations.)

 

[hawks]

Listen to what the Vendor told you he may be right as far as "YOU SEEING THE NAME OF THE PERSON THAT YOU ARE CALLING" but without the PRI circuit they will not see who is calling them and you will not see them when they call you. Someone correct me if I'm wrong, don't let the vendor point you to a plain Tie line if you are looking for caller information.

 

[coniglio]

okay, so it seems that the final say is I did need a PRI point-to-point so that when I lift my handset and dial access code 82 plus far-end-user's four digit extension i will see their name and they will see mine as though we were in the same office and 4-digit dialed each other, right? thankyou.

 

[senk1s]

I'm assuming both are meridians and both have MCDN enabled
MCDN is a nortel proprietery protocol that runs on top of a PRI that helps you acheive what you were discussing/ or already have implemented

 

[coniglio]

don't know about MCDN but i will check. Yes, they are both Meridians. By the way, these are NOT DID exts. To dial each other without using the access code we'd have to go thru the receptionist. It's just that we've gotten conflicting info as to whether the point-to-point T1 HAS to be PRI in order for us to see the far end's name and ext. Thank you for your help.

 

[sandyml]

If they are actually point-to-point between your two PBXs, then you would set up the PRI within each PBX, usually the configuration from the T1 provider is clear channel (they don't actually do the D-channel, you do). Is it actually point to point between your sites, or to somewhere else? Just curious..

 

[tipopen]

jgideon and sandyml are correct. If you have a point to point between two meridians you order a clear channel T1 b8zs/esf from your vendor and the meridiains provide the Dchannels making the trunks PRIs.

 

[coniglio]

it is a point-to-point T1 between two of our locations. We use it to call between offices and for nothing else. This circuit was ordered as a PRI so that we could see each others' names and exts. Needless to say I don't know what a clearw channel T1 is, but my question is, did this circuit NEED to be ordered as PRI or not? We are getting conflicting info as to whether we needed to pay more for a PRI in order to name and ext. thanks for your help.

 

[jgideon]

For a T1 between two switchs (not connecting to a carrier) you DO NOT need to order it as PRI. You need just a point-to-point T1 configured with coding/framing of b8zs/esf (which is 'clear channel'). Once the T1 is installed, you connect the two end points (pbx's) and the trunks on the PBX are configured as PRI between each other.

 

[janaya]

jgideon, you are the first person that I have seen post this. I don't know why people order TIE lines between PBX's as PRI or any other type of circuit except a straigth through pipe. Too much money is wasted on the extras. Let the PBX's control what type of line it is, that is what you spent that money on.

John