On 12/18/17 09:01, Baldur Norddahl wrote:
Hi
What options are available for 40G QSFP+ and 100G QSFP28 for 10+ km links?
I see a lot of switches offered with QSFP+ and QSFP28. But I do not seem to find the necessary optics to build the links I want.
For example, take a look at the options available at Fiberstore:
https://www.fs.com/c/generic-40g-qsfp-891
Generic Compatible 40GBASE-LR4 and OTU3 QSFP+ 1310nm 10km LC Transceiver for SMF $340
Generic Compatible 40GBASE-ER4 and OTU3 QSFP+ 1310nm 40km LC Transceiver for SMF $1500
https://www.fs.com/c/generic-qsfp28-100g-transceivers-2858
Generic Compatible QSFP28 100GBASE-LR4 1310nm 10km Transceiver $1999
Generic Compatible QSFP28 100GBASE-ER4 1310nm 40km Transceiver $7000
That is it. Four modules and the 40km are prohibitive expensive. The situation at other vendors appears to be similar.
I need stronger modules that can do more than 10 km without being extremely expensive. Or DWDM modules in the 1550 nm band so I can use external amplifiers. Am I looking in the wrong place? Is this expected to be available in the near future? qsfp28 is heavily constrained by power budget. The inability to put a serdes in the package does also very much constrain the form factor since it's 4x25 wavelengths.
cfp2-aco is the approach that stops paying for the DSP with every optic (DCO does that) gets you long haul single wave, DWDM and tunables, but it's a bit of an incovenient form-factor for fixed configuration 1ru switches.
Regards,
Baldur