[c-nsp] 10/100/1000 speeds in GE SFP ports

[Marian Ďurkovič]

On Thu Sep 25 17:20:40 EDT 2008, Saku Ytti wrote:
> On (2008-09-25 22:56 +0200), Asbjorn Hojmark - Lists wrote:

> > One funny thing is that the 6500 release note now (SXH) says:
> > "48-port Gigabit or 10/100/1000 Mbps Ethernet SFP" about the
> > 6748-SFP, where the previous (SXF) phrase was: "48-port Gigabit
> > Ethernet SFP".
> > 
> > I haven't had a chance to test if anything's actually changed,
> > though.
> > 
> > (Yes, I've also heard the 'It's a hardware limitation. Forget
> > it' story).
> 
> Someone commented on the list about his 6724 or 6748 being
> able to display DOM info, while lot of us had been told
> hardware is unable to read the upper half where the data lives.
> But he had newer hardware revision than any of mine, so
> it's entirely possible that there has been hardware upgrade,
> but I couldn't find anything in PCN about that change.
> 
> If there had been, perhaps they added multirate too? Sounds
> too good to be true though. Looking forward for someone
> to report back with SXI :)

DOM support on 6724 is not dependent on IOS version, it only depends
on HW revision of the 6724 linecard. HW rev. 3.0 or above is needed to
read DOM info.

There is no such support on 6748 yet AFAIK.

>From the technical point of view, DOM and copper SFPs are all communicating
over the same I2C bus where the SFP EEPROM is connected. The only difference
is that SFP EEPROM is at I2C address 0xA0, DOM is at 0xA2 and copper SFP
PHY-registers at 0xAC.

Thus, the change which enabled DOM for 6724 HW 3.0 cards is hardly any
hardware change - but more probably just new ASIC microcode. I still
don't understand why it's not yet shipped with new 6748 cards...


        With kind regards,  


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