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Where is generated the preamble?

Hi,

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, Michelot

Reply to
Michelot
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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

Reply to
Rich Seifert

Hi Rich,

Many thanks for your interresting reply.

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

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

802.3-2008.

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) type".

Thanks for this confirmation.

Thanks for your remarks, best regards, Michelot

Reply to
Michelot

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