From: Scott Morris (swm@xxxxxxxxxx)
Date: Mon Aug 26 2002 - 10:04:54 GMT-3
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.
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