nanog mailing list archives
Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that
From: Clayton Zekelman <clayton () MNSi Net>
Date: Mon, 17 Feb 2020 15:43:02 -0500
A PRI was and still is 23B+D, not 24 2B+D lines.23B+D (ISDN PRI or Primary Rate Interface) is 23x64 kbps bearer channels and a 64 kbps Delta channel carried on a B8ZS T1
You could carry additional groups of 24 B channels using NFAS, or Non-Facility Associated Signalling where the D channel on the first PRI carried the call setup and teardown information for the additional B channels on up to 20 PRI circuits.
2B+D (ISDN BRI or Basic Rate Interface) 2x64 kbps bearer channels and a 16 kbps Delta channel carried on an 144 kbps 2B1Q U interface.
At 02:58 PM 27/01/2020, bzs () theworld com wrote:
FWIW bulk dial-up lines were often brought in as PRIs which were 24 ISDN 2B+D lines on basically a T1 (1.544mbps) and then you could break those out to serial lines.
Current thread:
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that, (continued)
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Gene LeDuc (Feb 17)
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Anne P. Mitchell, Esq. (Feb 17)
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Clayton Zekelman (Feb 17)
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that nanog08 (Feb 17)
- Re: [EXTERNAL] Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Gene LeDuc (Feb 17)
- Re: [EXTERNAL] Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Paul Ebersman (Feb 17)
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Brian (Feb 17)
- Re: Reminiscing our first internet connections (WAS) Re: akamai yesterday - what in the world was that Ben Cannon (Feb 17)