Re: ClockRate confusion

So you're using synchronous serial modules connected to external CSU/
DSUs or you're using true T-1 modules internal to the routers? You
can't set the clock rate of a T-1 module; that applies to synchronous
serial modules configured to act as DCE. (The command may well be
accepted, but you cannot configure a T-1 CSU/DSU to send at any rate
other than as close to exactly 1.544 Mbps as possible.) What you can
set on a T-1 module is the clock >source< (e.g. recovered from the
line or an internal oscillator). Here's a very simplistic example of
using the 'clockrate' command for a back-to-back HDLC serial
connection (note the 'sh controllers' output):

http://www.cisco.com/en/US/tech/tk713/tk317/technologies_configuration_example09186a00800944ff.shtml

Even if you were using synchronous serial interfaces connected to
external CSU/DSUs, the typical configuration would be that both
routers would act as DTEs and the CSU/DSUs would act as DCEs providing
clock to the routers. The CSU/DSUs would either recover clock from
the network (provided by DACS within the carrier cloud) or one would
provide the timing and the other would recover it. Here again, the
'clockrate' command would have no bearing (even if accepted and
displayed in the config) because the routers wouldn't be providing a
clock (and thus rate would be completely meaningless).

On Jan 4, 2011, at 7:54 , Routing Freak wrote:

> I have R1-----------------R2 R1 is connected to R2 with a
> serial
> 1.544Mbps T1 link and i am configuring clock rate as 128000 (ie
> 128kbps)
> tat means whether when traffic is sent from R1 to R2 it will send
> only 128
> kbps or else 1544 kbps per second
> Can anyone explain me clearly
>
>
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Received on Tue Jan 04 2011 - 13:28:20 ART