From: Scott Morris (swm@xxxxxxxxxx)
Date: Mon Aug 26 2002 - 15:24:09 GMT-3
I'm not sure I understand what you're getting at... A T-1 is a trunk
facility, reprenting multiple channels (24 of them) across a single
physical medium. Nowdays, there generally DS-1's, which just means it
is a digital signal. Technically speaking T-1 is a terrestrial, analog
signal, but most people use the names interchangeably, so I wouldn't
sweat much about it.
You might consider doing some research on voice in the 1940's and 1950's
to get some history behind the T-1, but it's really just a TDM trunk
sharing multiple lines or "channels" simultaneously. In the data world
we generally don't care about that unless we're planning to create
channel-groups or worry about dial-up stuff. For data guys, a line is a
line is a line (sometimes anyway!). :)
Hope that helps!
Scott
-----Original Message-----
From: Michael Spencer [mailto:labmich2002@yahoo.com]
Sent: Monday, August 26, 2002 2:00 PM
To: swm@emanon.com; 'Richard Foltz'; ccielab@groupstudy.com
Subject: RE: T1 line
Hi Group,
Thanks for your help. One more question, what could be
the best definition of T1.
TIA
--- Scott Morris <swm@emanon.com> wrote:
> Simple math actually...
>
> 24 channels x 64k per channel = 1536Kbps or
> 1.536Mbps of actual
> BANDWIDTH
>
> Now, when we look at the actual bits that are sent.
> Within a T-1 frame,
> there are 8 bits per channel (24 * 8 = 192 bits).
> However, there's a
> single framing bit too, used for synchronization and
> other functions.
> So 193 bits per frame, at 8,000 frames per second
> gives us 1.544 Mbps of
> actual BIT RATE.
>
> Some serial interfaces (and it actually depends on
> the model of router
> and version of IOS) actually count the full bit
> rate!
>
> Hope that helps!
>
> Scott
>
> -----Original Message-----
> From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com] On Behalf Of
> Richard Foltz
> Sent: Monday, August 26, 2002 8:41 AM
> To: Michael Spencer; ccielab@groupstudy.com
> Subject: Re: T1 line
>
>
> Minor correction. A T1 has 24 channels. If you use a
> PRI then you are
> using one of the channels for signalling (D
> Channel). But a T1 itself is
> 24 channels.
>
> Richard Foltz, CCIE#8339
>
> ----- Original Message -----
> From: "Michael Spencer" <labmich2002@yahoo.com>
> To: <ccielab@groupstudy.com>
> Sent: Monday, August 26, 2002 6:46 AM
> Subject: T1 line
>
>
> > The speed of T1 line is 1.544Mbps. The T1 is
> consists of 23B(64K)
> > channels
> and one D channel(64K). If we do the simple
> arithmetic then it comes out
> to be 1.536Mbps. Then why the serial interfaces are configured as
> default 1.544Mbps.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > ---------------------------------
> > Do You Yahoo!?
> > Yahoo! Finance - Get real-time stock quotes
> >
>
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