It really depends on what you're interconnecting. Some NICs don't support SM optics, so even if you would like to run SM everywhere, it's not necessarily possible depending on the equipment. For example, I had issues with some SolarFlare cards which happily take 10G-SR MM but won't take 10G-LR SM.
Filip On 26 February 2020 5:30:56 pm GMT+01:00, Warren Kumari <war...@kumari.net> wrote: >On Wed, Feb 26, 2020 at 11:20 AM Coy Hile <coy.h...@coyhile.com> wrote: >> >> On 2020-02-26 11:14, Randy Bush wrote: >> >> We use plenty of multi-mode, but only in the data centre, between >our >> >> own kit, for racks within the same cage. >> > >> > so you have to stock both single and multi? hmmm >> > >> > randy >> >> I'd expect that from the ToR -> Servers would be MMF, but that other >> infrastructure cabling would be SMF. >> Even using aftermarket optics, putting single-mode transceivers in >every >> server and access port would quickly become cost-prohibitive, would >it >> not? > >Cisco GLC-SX-MM Compatible 1000BASE-SX SFP 850nm 550m DOM Transceiver >Module - $6.00 - https://www.fs.com/products/11774.html >Cisco SFP-GE-L Compatible 1000BASE-LX/LH SFP 1310nm 10km DOM >Transceiver Module - $7.00 - https://www.fs.com/products/12622.html > >Yup, it is $1.00 more for SM, and you need 2 per link, but unless you >are doing *lots* that's likely not cost-prohibitive. The delta on 10G >is a bit more ($21 vs $18), but still not crazy-pants territory... > >Of course, sometimes you don't have the option of SM - you are >connecting some someone else than they only do MM, or you are >connecting to a piece of kit which doesn't have replaceable optics, or >you have legacy cabling which is MM, or... but, the cost of the optics >these days is not really the limiting factor. > >> >> -- >> Coy Hile >> coy.h...@coyhile.com > > > >-- >I don't think the execution is relevant when it was obviously a bad >idea in the first place. >This is like putting rabid weasels in your pants, and later expressing >regret at having chosen those particular rabid weasels and that pair >of pants. > ---maf -- Sent from my mobile device. Please excuse my brevity.
