Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: Hari and train-up sequences

Hi Brad,

I'd like to see a link initialization defined at the PCS layer
between a local device and link partner.

It's something we need and something which doesn't have to
be complex.

A two-way handshake may look like 1) one end sends a stream of Link
messages indicating it is in the init state 2) the remote side must
respond with the Link message (some 10b codegroups chosen for this) and
after some time Link messages with acknowledges 3) when the local side
receives these it sends Link acknowledges for some time 4) when
either side receives Link acknowleges they are done and send Idles.

So the PMA would need to be ready before the Link message with 
acknowleges are sent. By HARI I assume you mean PMA. HARI is the
interface between the PMA and PMD.


> Delivered-To:
> X-Received: 16 Nov 1999 22:27:12 GMT
> From: "Booth, Bradley" <bradley.booth@xxxxxxxxx>
> To: stds-802-3-hssg@xxxxxxxx
> Subject: RE: Hari and train-up sequences
> Date: Tue, 16 Nov 1999 13:01:03 -0800
> MIME-Version: 1.0
> X-Resent-To: Multiple Recipients <stds-802-3-hssg@xxxxxxxxxxxxxxxxxx>
> X-Listname: stds-802-3-hssg
> X-Info: [Un]Subscribe requests to  majordomo@xxxxxxxxxxxxxxxxxx
> X-Moderator-Address: stds-802-3-hssg-approval@xxxxxxxxxxxxxxxxxx
> X-SMTP-MAIL-FROM: owner-stds-802-3-hssg@xxxxxxxx
> X-SMAP-Received-From: outside
> I need some clarification here.  Are you proposing a link initialization for
> the Hari?  If so, are you also proposing a link initialization for the local
> device to link partner connection?  If you're proposing both, then are you
> proposing to have 3 stages of link initialization?  If so, I believe that
> this may add more complexity than we need to deal with.
> Cheers,
> Brad
> 	-----Original Message-----
> 	From:	Linda Cheng [SMTP:linc@xxxxxxxxx]
> 	Sent:	Tuesday, November 16, 1999 12:48 PM
> 	To:	stds-802-3-hssg@xxxxxxxx
> 	Subject:	Re: Hari and train-up sequences
> 	That's right. The deskew logic can made easier. If it looks for 
> 	Link codes which come every N idles, where N = 4 for example, 
> 	the window is bigger than deskewing off of idles. And there is a
> distinct 
> 	beginning and end to the deskew period.
> 	Linda
> 	> Note that both the Hari byte-striping and word-striping proposals
> benefit 
> 	equally
> 	> from the definition of a link initialization sequence.
> 	> 
> 	> Best regards,
> 	> Rich
> 	> 
> 	> --

Linda Cheng			Cisco Systems 
				Desktop Switching Business Unit
(408) 527-2015 (phone)		170 West Tasman Drive
(408) 527-4698 (fax)		San Jose, CA 95134-1706