1000 Base-X auto-negotiation

1000 Base-X auto-negotiation

Post by Michael Zayat » Tue, 15 Jul 2003 01:58:33



Hi people,

I am working on some home-grown PCI card with 1000 Base-X ethernet. My
problem is that it fails on auto-negotiation step (against some Intel
card). Getting it through the sniffer has shown that there are
adverti*ts from both side, sometimes my card sets ACK bit, while the
other side doesn't set ACK at all.

A few questions:
1) Can somebody point me to some well-written (not the ieee standard,
please) summary of AG process for fiber?

2) Could it be that my TX signal is too weak? How can I measure it?

3) Can somebody explain me about SX/LX modes and their compatibilities
issues?

Some system info:
I use BCM2410s phy with OCP DTR-1250-MM-LS-AC-M tranceiver

TIA,

Michael Zayats

 
 
 

1000 Base-X auto-negotiation

Post by Rich Seifer » Tue, 15 Jul 2003 09:24:52




Quote:> Hi people,

> I am working on some home-grown PCI card with 1000 Base-X ethernet. My
> problem is that it fails on auto-negotiation step (against some Intel
> card). Getting it through the sniffer has shown that there are
> adverti*ts from both side, sometimes my card sets ACK bit, while the
> other side doesn't set ACK at all.

> A few questions:
> 1) Can somebody point me to some well-written (not the ieee standard,
> please) summary of AG process for fiber?

There is a discussion of automatic configuration for 1000BASE-X in
Chapter 12 of my book, "Gigabit Ethernet", available at:

http://www.veryComputer.com/
002-9365671-3540840

Quote:> 2) Could it be that my TX signal is too weak? How can I measure it?

This is possible; you can measure the output level with an optical power
meter. If the cables are short, the optical power is not likely to be a
problem.

Quote:> 3) Can somebody explain me about SX/LX modes and their compatibilities
> issues?

> Some system info:
> I use BCM2410s phy with OCP DTR-1250-MM-LS-AC-M tranceiver

I am not familiar with these particular components. As to compatibility,
you both ends MUST be using the same wavelength (either short-wave or
long-wave). Longwave will operate over either singlemode or multimode
fiber (shorter distance on multimode); short wave requires multimode
fiber.

The automatic configurating algorithm can NOT resolve problems of either
wavelength or cable type; it assumes that the ends and cable are all
compatible. Automatic configuration ONLY resolves duplexity and flow
control, in 1000BASE-X.

--
Rich Seifert              Networks and Communications Consulting

(408) 395-5700            Los Gatos, CA 95033
(408) 395-1966 FAX

 
 
 

1000 Base-X auto-negotiation

Post by Jo » Mon, 21 Jul 2003 22:59:35


I have a couple of Rich's books. My favorite is The Switch Book. Most
definitely recommended.

> Hi people,

> I am working on some home-grown PCI card with 1000 Base-X ethernet. My
> problem is that it fails on auto-negotiation step (against some Intel
> card). Getting it through the sniffer has shown that there are
> adverti*ts from both side, sometimes my card sets ACK bit, while the
> other side doesn't set ACK at all.

> A few questions:
> 1) Can somebody point me to some well-written (not the ieee standard,
> please) summary of AG process for fiber?

> 2) Could it be that my TX signal is too weak? How can I measure it?

> 3) Can somebody explain me about SX/LX modes and their compatibilities
> issues?

> Some system info:
> I use BCM2410s phy with OCP DTR-1250-MM-LS-AC-M tranceiver

> TIA,

> Michael Zayats

 
 
 

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