Hi Mitch, Your answer helps a lot, thanks! I think the existence of the old 100 standard explains conflicting information found on google search.
To constrain the scenario a bit: we don’t want to use a deprecated standard. And though it was buried, I did specify that the 100 G standard we were starting from was QSFP28. So it would seem it is *not* convenient to transform QSFP28 into 10x SFP+, at least to your understanding. Is that right? If anyone else can comment on what I hope is a clearer framing of the question, I would appreciate it. Thanks, Jonathan > On Nov 30, 2022, at 11:43 AM, Mitch Burnett <[email protected]> wrote: > > Hi Jonathon, > > I probably will not be answering your question completely. But perhaps just > a bit of input for some further searching? > > My understanding is that the first generation 100G PHY standard was IEEE > 802.3ba-2010 and that used 10 lanes at 10G line rates. However, I believe the > only standard that used a SFP based module was the copper 100GBASE-CR10 using > a QSFP+ transceiver. The rest were the CX style transceiver modules. > > And so most 100G switches using QSFP28 transceivers this would not be a > standard implementation they would support because the underlying line rate > is the 28Gbps. Typically what I see for example is that each port of a > 32-port 100G QSFP28 switch can be configured as 32 40G ports that then is > based on the SFP+ standard for 10G and can do 128 10G ports. > > So using QSFP28/SFP+ where the underlying line rate in the PHY is 28Gbps may > not be feasible (however I am not an authority here and cannot say it doesn’t > exist). But again, there is an old standard that does use 10x10 and you may > be able to follow that route if interested? But it is old technology and > probably hard to come by? > > Best, > > Mitch > >> On Nov 30, 2022, at 9:09 AM, 'Jonathan Weintroub' via >> [email protected] <[email protected]> wrote: >> >> Hi CASPERites, >> >> I believe that 40 Gbps Ethernet interoperates rather transparently with 10 >> Gbps. Because the 40 Gbps is arranged as four x 10 G lanes, so its >> possibly to break a 40 QSFP port into four 10 SFP+ with a suitable breakout >> cable. Or with proper packet addressing via a network switch with 40 and 10 >> ports. >> >> Likewise 100 Gbps interoperates with 50/25 easily. And 400 with 200 and 200, >> and so on. >> >> The question arose in a meeting today whether it’s a simple matter to >> transform a 100 Gbps Ethernet stream into 10 Gbps streams, 10 of them or >> whatever? There are various switches on the market with both 100 and 10 Gbps >> ports, but not clear whether these re distinct networks, or whether they >> transparently interoperate. >> >> Can someone offer input as to whether transforming 100 Gbps QSFP28 into >> multiple 10 Gbps SFP+ links is easily accomplished in a suitable switch? Or >> a complicated endeavor? >> >> Hope this is clear. Thanks, >> >> Jonathan >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "[email protected]" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://www.google.com/url?q=https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/1C6A1476-CBFD-4498-9DE5-2DE747741556%2540cfa.harvard.edu&source=gmail-imap&ust=1670431410000000&usg=AOvVaw0E-4FWmowXFs2Vap0k4io9. > > -- > You received this message because you are subscribed to the Google Groups > "[email protected]" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://www.google.com/url?q=https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/0DE96746-94B2-485E-8F76-445EE24A5136%2540byu.edu&source=gmail-imap&ust=1670431410000000&usg=AOvVaw2V04Gay2d2NlGlbvrcDLDX. -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/F96BDF14-D29D-4ADC-914A-44FA4915E22D%40cfa.harvard.edu.
