1000BaseSX 1000BaseLX confusion?

[Richard A Steenbergen]

On Mon, Aug 08, 2005 at 03:52:14PM -0400, Steve Shorter wrote:
> Howdy!
> 
> 	I was wondering how come the listed media types supported
> by sk(4) and em(4) is only 1000BaseSX. Even for single mode
> 1000BaseLX NICs such as sk 9841 and Intel PWLA8490LX, ifconfig
> show the media type as 1000BaseSX. Though the NIC appears to operate in
> single mode connected to a LX switch port ok.
> 
> 	From what I can understand SX supports only multimode fibre
> and LX supports both.
> 
> 	How come there isn't 1000BaseLX for a displayed media type, and
> is it really single mode?

Probably because no one ever bothered writing in support for it. :)

As far as the fbsd driver is concerned, it is all the same thing. You 
can't switch the optics in software, it is what it is based on the optical 
component that was physically installed on the card (ignoring pluggables 
for the moment :P). That makes it purely a cosmetic issue.

But that said:

# find . | xargs grep IFM_1000_LX
./net/if_media.h:#define        IFM_1000_LX     14              /* 1000baseLX - single-mode fiber */
./net/if_media.h:       { IFM_1000_LX,  "1000baseLX" },                        \
./net/if_media.h:       { IFM_1000_LX,  "1000LX" },                            \
./pci/if_sk.c:          sc->sk_pmd = IFM_1000_LX;
./pci/if_sk.c:  case IFM_1000_LX:

For shame. :)

There are a lot of optics out there besides SX and LX, or besides SR and 
LR in 10GE. I know nothing about fbsd's level of support for SFP based 
cards, but I would imagine it isn't going to be good based on the above.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)