Basic PBX Question... 2

[mutpup]

Hey All, I'm just trying to get a basic understanding of digtial telephone systems. If I have a T1 connection coming in from the tele co. Then how many outgoing calls can I have at one time?

Should it be 24 since a t1 can carry 24 digitized voice channels? or am I missing sometihg fundamental?

Bear with me as I am router/IT guy and know nothing about digital phone systems...

Thanks in advance for you information..

 

[linesclan]

Hi

As long as your system is set up to dial externaly you should be able to make and reciave 24 calls all at the same time,

thanks
linesclan

 

[stug]

Yes there are 24 channels but one is used for signalling called a D channel so you have 23 lines for making calls

 

[vaoldschl]

Stug, ISDN-PRI (23 Bearer and 1 Data) and ISDN-BRI (2 Bearer and 1 Data) use a D channel. Standard T1 does not. With basic T1 service you are able to use all 24 channels but you lose some of the intelligence associated with ISDN.

 

[moose4me]

A basic T-1 will give you 24 channels that can be used for outgoing/incomming calls. A T-1 installed as a PRI (primary rate interface) will give you 23 channels for outgoing/incomming calls and a single channel, usually #24, as a D-channel which is used to build/tear down calls.

 

[jerryreeve]

On a straight T-1 you do have 24 channels. Unfortunately (with most telco's) on a straight T-1 you normally have to assign each channel to a type of service ie. DID, incoming Trunk, outgoing trunk. So you may not have all of your channels available even though they may not all be busy. the advantage to PRI is that it can be set up on a call-by-call basis where any channel can handle any style of call. JerryReeve
Communications Systems Int'l
com-sys.com