[c-nsp] Cisco and third party transceivers

[Martin T]

Mikael,
this SFP in Gi1/0/1 which I used as an example in my previous email is
bought from China from noname manufacturer and doesn't work without
"service unsupported-transciever" if I remember correctly. At least
the IDPROM of this SFP doesn't look like a Cisco one, does it?
However, it supports DDM just fine as I showed.


Nick,
I haven't worked much with newer Cisco switching products, but it's
sad to hear this. Do you happen to know some particular products? At
least Flexoptix would be happy about such trends :)


regards,
martin


2011/9/30 Nick Hilliard <nick at foobar.org>:
> On 30/09/2011 00:39, Martin T wrote:
>> ..but manufactured in Asia. On the other hand, there are manufacturers
>> like Finisar, Prolabs, Agilent etc, which make decent transceivers as
>> much as I have experience. In addition, according to this article:
>> http://www.lightreading.com/document.asp?doc_id=102950 ..Cisco buys
>> SFP directly from Finisar. Do you see a difference in "Cisco branded
>> Finisar SFP" and "Finisar SFP" other than content of EEPROM?
>
> Cisco buys transceivers from several companies.  Sometimes the same product
> SKU from a particular vendor might actually be sourced from several
> different transceiver manufacturers.  Do you think for a moment that that a
> GLC-LH-SM bought in 1999 is going to be exactly the same component as a
> GLC-LH-SM bought in 2011?  Of course it isn't.
>
> Transceiver compatibility is a really difficult area.  And one transceiver
> is not the same as another.  Bugs slip into the transceiver firmware and
> hardware.  Some vendors produce complete trash.  Some vendors produce
> really high quality products (e.g. finisar, opnext, etc)
>
>> It's a third-party SFP directly from China. As much as I understand,
>> it doesn't have any sort of Cisco-branding, does it? Regardless it
>> supports DDM.
>
> DDM is defined in SFF8472.  It's nothing particularly to do with Cisco.
>
>> In addition, in the past, has there been times where one really was
>> forced to use transceivers with Cisco serials because there were no
>> "service unsupported-transceiver" and "no errdisable detect cause
>> gbic-invalid" commands? Maybe some seasoned network engineer
>> remembers..
>
> Yes, that was the case in the past.  And unfortunately, Cisco have recently
> either deliberately started ignoring "service unsupported-transceiver" on
> some of their new products, or else the transceiver device drivers are
> sufficiently portably written that they no longer work with many types of
> transceiver.  Either way, transceiver compatibility problems are rearing
> their ugly head again in a major way.
>
> Nick
>