# Talk:Primary Rate Interface

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## Early question

what is a pri --22:22, 27. Feb. 2007 70.21.121.18

As discribed in the article. Or what else do you mean? --Uweschwoebel 21:48, 28 February 2007 (UTC)
I think he means, what does the acronym it stand for? I see it referred to as Primary Rate ISDN Family Guy Guy (talk) 02:35, 9 November 2011 (UTC)

How does 30 B channels and 1 D channel add up to 2.048Mbits/second?

There are in fact 32 channels: Channel 0 is used for framing and synhronisation, channels 1 through 15 are B channels, channel 16 is the D channel, and channels 17 through 31 are the remaining B channels. 32 times 64 kbit/s equals 2.048 Mbit/s. See E-carrier for more info. JanCeuleers 15:25, 20 May 2007 (UTC)

What is the differnece between E1 and PRI? —Preceding unsigned comment added by 202.138.120.65 (talk) 16:42, 29 March 2008 (UTC)

A PRI is a specific type of T1 or E1. Bellhead (talk) 22:20, 31 March 2008 (UTC)
More accurately, a PRI is a service provided on a T1 or E1 and frequently (but incorrectly) considered to be one and the same with the T1/E1. Bellhead (talk) 15:08, 22 October 2008 (UTC)

## Not always 23B+1D

When using PRIs for voice, they can be stacked together. For example, you can have one PRI with 23 B channels and 1 D channel and the second have 24 B channels, using the one D channel for signaling. If you had four PRIs, it wouldn't be uncommon to have two 23B+1D PRIs and two 24B PRIs - two D channels for redundancy. 205.154.230.126 (talk) 01:33, 2 July 2008 (UTC)

I think that this is at least touched upon in Primary rate interface#Fractional T1. — Dgtsyb (talk) 09:29, 2 July 2008 (UTC)
See Non-Facility_Associated_Signalling Tomgreeny (talk) 15:39, 2 July 2008 (UTC)

PRI and E1/T1 have same data rate but differ in respect that E1/T1 purely work on layer 1 and PRI is a Layer 2 technology thier is HELL OF A DIFFERIENCE. BAD ARTICLE please improve —Preceding unsigned comment added by 119.153.57.90 (talk) 19:58, 4 February 2009 (UTC)

The section on E1 is incorrect both in total bandwidth available and details. E1s have 32 channels (0-31), 0 = framing, 1-15 = B-channels, 16 = signalling (d-channel), 17-31 = b-channels. This has been incorrect since 2007, please fix as it has been pointed out twice in this discussion so far. 83.71.151.18 (talk) 10:17, 16 June 2011 (UTC)

So where was the error?—Dgtsyb (talk) 16:36, 18 June 2011 (UTC)