T1 or Not

[werhol2303]

What is the diffrence between isdn-pri and robbed-bit? How can I tell if this is T1 or Not?
This is conf from my Definity.


SYSTEM CONFIGURATION - DS1 Circuit Packs

Location Code Vintage Signaling Name CSU MOD

01A14 TN464F 000018 isdn-pri PZD002643-1 120A2
01A15 TN767E 000014 robbed-bit WZ24720 120A2
01A16 TN767E 000014 robbed-bit WZ24721 120A2
01B16 TN767E 000018 robbed-bit confserver1 120A2
01B17 TN767E 000018 robbed-bit confserver2 120A1
01B18 TN464F 000014 isdn-pri PZD002643-2 120A2

 

[jgideon]

They're all technicall T1's--it's a question of signalling. If it's PRI, it's out-of-band signalling (there is a d channel). If it's 'robbed bit', it's 'in-band' signalling, so wink or loop start and touch tone usually. (PRI's are delivered on a T1 circuit)

 

[mikeydidit]

The best I can find out is they are all T-1's. The differances is in the associated signaling. Your TN464's are PRI and have a signaling group (the 24th channel) and the robbed bit doesn't. It randomly grabs whatever channel for it's signaling. Thats also why the PRI's are on 464 packs. On the DS1 form the robbed bit is found under the signaling mode. From what I understand this sort of veri's from one vendor to the next.

Hope this helps.

"Wise men speak because they have something to say; Fools because they have to say something."
(Plato)

 

[werhol2303]

Thank you.

 

[orypecos]

The robbed bit method is fine with voice, because voice will not notice a little reduction in the bandwidth occasionally, but data will not allow any 'robbing' with having to resend or permanent loss of data.
So with robbed bit, you get an extra channel going out of your PBX, but data will suffer.
Also, the ISDN can share a control channel to give back one of your channels used for control.

 

[phonewiz]

In your list config DS1 all of these are considered T1's and the main difference between them is that the robbed-bit T1's are basically plain vanilla T1's that have 24-b channels which carry voice traffic in and out of your switch. The ISDN-Pri has 23-b channels and 1-d channel and again the b channels carry all of your incoming and outgoing calls and the d-channel carries all the signalling from the central office and also delivers the caller-ID information that shows on your telephone set display. I hope that answers your question.