From: Przemyslaw Karwasiecki (karwas@xxxxxxxxxxxxx)
Date: Thu Aug 22 2002 - 19:11:02 GMT-3
Ethernet is using something called Manchester encoding.
It basically means, that in order to provide clock synchronization
between frame transmitter and receiver, each zero is represented
by sequence of 01 and each one is represented by 10.
By doing so, it makes it possible to maintain clock synchronization
even in case frame contains long sequence of zeroes or ones.
And, yes, before each frame, there is a short sequence send
called preamble (but I believe this is layer 1 not 2),
which makes it possible to delineate beginning of the frame.
Is it synchronous -- IMHO yes, but it depends on definition
of the term synchronous.
Przemek
On Thu, 2002-08-22 at 17:17, Michael Snyder wrote:
> Where's the clock?
>
> Believe every Ethernet transmission starts with a series of one's and
> zero's sent before the packet header.
>
> This layer two header provides the clock. So it it's async before the
> packet is transmited, and synced as the packet is transmited.
>
> Does this help?
>
> I have a better question for you, is ATM sync or async. Really? You
> don't think there's a sync'ed clock signal on the fiber cables. About
> as clear as mud huh?
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Michael Spencer
> Sent: Thursday, August 22, 2002 1:04 PM
> To: ccielab@groupstudy.com
> Subject: ethernet
>
> Is ethernet synchronous or asynchronous?
>
>
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