Leave it to the Western Electrics to use something almost too simple like the alphabet to use for designations. And I've heard many use T1 and DS1 interchangably. In fact, I think the spec actually calls out "DS-1" and doesn't really reference T1.
According to Harry Newton's _Newton's Telecom Dictionary_, 1992, page 871: he states the following - "... Outside the United States and Canada, the "T-1" line bit rate is usually 2,048,000 bits per second. Japan, France and West Germany impose slight variations that make their formats unique. Only one element remains constant - the DS-0. The 64 kilobit per channel is universal. ..." I thought the E-1 rate was standard no matter where it's used. Harry's saying there are "slight variations". What's that supposed to mean? Also in Harry Newton's _Newton's Telecom Dictionary_, 1992, page 870: he lists the following - "... North American Designator (DS LEVEL) T1 (DS-1) 1.544 Mbps 24 voice channels T1C 3.152 Mbps T2 (DS-2) 6.312 Mbps 96 voice channels T3 (DS-3) 44.736 Mbps 672 voice channels T4 (DS-4) 274.176 Mbps 4032 voice channels Japanese Hierarchy - DS Level DS-1 1.544 Mbps 24 voice channels DS-2 6.312 Mbps 96 voice channels DS-3 32.064 Mbps 480 voice channels DS-4 97.728 Mbps 1440 voice channels DS-5 400.352 Mbps 5760 voice channels European (CEPT) DS Level DS-1 2.048 Mbps 30 voice channels DS-2 8.448 Mbps 120 voice channels DS-3 34.368 Mbps 480 voice channels DS-4 139.268 Mbps 1920 voice channels DS-5 565.148 Mbps 7680 voice channels ..." John Combs wrote: > > >Date: Tue, 8 Sep 1998 20:40:59 -0700 (PDT) > >From: Douglas L McKean <[email protected]> > > >And I've had quite a few lively discussions as to the > >difference between T1 and DS1. T1 is simply circuit > >constructed to respond optimally to a DS-1 signal. > > Actually, I have been told (by some GTE "old timers" <g>) that T1 is a > proprietary Western Electric term. They didn't exercise a whole lot of > imagination, they simply used the next letter of the alphabet when they > built a new system. (So that's why we have M-carrier systems in the Bell > System <g>). DS1 is the "generic" term (Digital Service 1). > > ________________________________________________________________ > John Combs, Senior Project Engineer, ITS/TestMark Laboratories > Email: [email protected] URL: http://www.testmark.com
