Where is generated the preamble?

Have a question or want to start a discussion? Post it! No Registration Necessary.  Now with pictures!

Threaded View

I don't know if someone will see my message within spams.

Is it the RS (reconciliation sublayer) that generates the preamble, or
it comes higher, from the MAC sublayer.

We can refer to the figure 22-1 in 802.3-2008.

Best regards,

Re: Where is generated the preamble?
Quoted text here. Click to load it

The preamble is defined as part of the MAC frame, i.e., it is
generated (architecturally) by the MAC.

However, since hardware implementations are not partitioned by
abstract architectural considerations, the specific layer/sublayer is
irrelevant. The preamble is generated by the Ethernet chip or core.

Rich Seifert                Networks and Communications Consulting
                                 21885 Bear Creek Way
(408) 395-5700            Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

Re: Where is generated the preamble?
Hi Rich,

Many thanks for your interresting reply.

Quoted text here. Click to load it

Thanks for this statement, written like this. I have to note that for
my students.

Quoted text here. Click to load it

There is a slightly difference between 802.3-2005 (or before) and

In 802.3-2005, figure 3-1, we see that the MAC frame format include
the preamble and SFD.

In 802.3-2008, it is mentionned:

Section 1.4.212: "MAC frame: Consists of the Destination Address,
Source Address, Length/Type field, MAC Client
Data, Pad (if required), and Frame Check Sequence".

Section  1.4.259: "packet: Consists of a MAC frame as defined
previously, preceded by the Preamble and the Start
Frame Delimiter, encoded, as appropriate, for the Physical Layer (PHY)

Quoted text here. Click to load it

Thanks for this confirmation.

Thanks for your remarks,
best regards,

Site Timeline