nanog mailing list archives
Re: PCIe adapters supporting long distance 10GB fiber?
From: Denys Fedoryshchenko <denys () visp net lb>
Date: Wed, 21 Jun 2017 00:07:39 +0300
On 2017-06-20 23:44, Baldur Norddahl wrote:
But what foundation do you have for asserting that switch hardware is anyFor switches i guess it is same story as for PoE on them - total power budget matters. So if you will pack whole EX4500 with 10G 80km SFP+ it might have problems as well, but for normal use, and if few only are "long distance/high power", at any case 3.3V supply rail by design in switch should handle many SFP, so if there is 48 ports, it should handle by specs at least 72W peak load. It might be multiple power rails for groups of ports, but still, much better than just 750mA on network card. But that's just guessing, i never seen circuit diagrams of good switches, or at least reference design,different in this regard? I can say that we are using 80 km modules invarious hardware without any issues. I admittedly do not use any high powermodules in servers, but I will need better evidence than this to assume that it would not work just fine.
as it is all NDA material.
Den 20. jun. 2017 22.24 skrev "Denys Fedoryshchenko" <denys () visp net lb>:On 2017-06-20 22:07, Baldur Norddahl wrote:I would expect anything mounted in a computer to have all the power you could want. It is not like the ATX power supply cares about an extra wattSFP needs 3.3V, it might be supplied from regulator on the card or directlyor two. As I understand the issue it is more about cooling than power and isprimarly a concern in high density switches were you could have 48 or moreto power and cool.PCI-Express,can't be absolutely sure, in reference design it is just 3.3V_NIA and thenfilter,also reference design SFP power circuit define max 750mA/3.3V max to SFP,thats only 2.475W. FTLX1471D3BCV (10km SM) - up to 285mAFTLX1671D3BCL (40km SM) - up to 400mA, and thumb rule in electronics it isbetter to not exceed 50%of max specs of designed max current, as for many parts it is stated for25C & etc operating conditions.I expect it might work, but noone knows how long, and how reliable, if itis not cooled very well.And 82599 sensitive to cooling(it is very old card after all), as soon asit is not enough, it starts to glitch.Den 20. jun. 2017 18.09 skrev "Denys Fedoryshchenko" <denys () visp net lb>:I guess it depends on NIC, there is many spinoffs of Intel X520 with muchweaker power supply circuitry.It might work with good NIC, but you can't rely on it on long term, IMHO. Even 40km Finisar SFP+ has Pdiss 1.5W. Also they mention: "The typicalpower consumption of the FTLX1672D3BTL may exceed the limit of 1.5W specified for the Power Level II transceivers" If we talk about 80km, Pdiss is 1.8W. While 10GBASE-LR is <1W On 2017-06-20 16:30, Max Tulyev wrote: We use Intel NICs with SFP+ holes. It works good with long and shortrange SFP+ modules, including CWDM/DWDM. On 15.06.17 12:10, chiel wrote: Hello,We are deploying more and more server based routers (based on BSD). We have now come to the point where we need to have 10GB uplinks one these devices and I prefer to plug in a long range 10GB fiber straight into the server without it going first into a router/switch from vendor x. Itseems to me that all the 10GB PCIe cards only support either copper10GBASE-T, short range 10GBASE-SR or the 10 Km 10GBASE-LR (but only very few). Are there any PCIe cards that support 10GBASE-ER and 10GBASE-ZR? Ican't seem to find any. Chiel
Current thread:
- PCIe adapters supporting long distance 10GB fiber?, (continued)
- PCIe adapters supporting long distance 10GB fiber? chiel (Jun 19)
- Re: PCIe adapters supporting long distance 10GB fiber? Karsten Elfenbein (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Mikael Abrahamsson (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Alain Hebert (Jun 21)
- RE: PCIe adapters supporting long distance 10GB fiber? Aaron Gould (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Max Tulyev (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Denys Fedoryshchenko (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Baldur Norddahl (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Denys Fedoryshchenko (Jun 20)
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- Re: PCIe adapters supporting long distance 10GB fiber? Baldur Norddahl (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Denys Fedoryshchenko (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Mikael Abrahamsson (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Baldur Norddahl (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Jim Shankland (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Jörg Kost (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Chris Adams (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Hunter Fuller (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? Denys Fedoryshchenko (Jun 20)
- Re: PCIe adapters supporting long distance 10GB fiber? James Bensley (Jun 21)
- Re: PCIe adapters supporting long distance 10GB fiber? Oliver Elliott (Jun 22)
- Re: PCIe adapters supporting long distance 10GB fiber? Mike Tancsa (Jun 20)