Future-ready networking

[sonofdbn]

I have a Supermicro X10SDV-TLN4F which has two 10GbE ports for one of my unRAID servers. I bought it many years ago when 1GbE was considered fast, thinking that networking speeds would go up quickly and costs would come down even faster. Things didn't work out that way and now it seems that for consumer level hardware, 2.5GbE is the norm, and that's what I have on my second server. Right now, all my switches are 1GbE, and I've never used the 10GbE capabilities of the server.

 

So I'm thinking of upgrading the switches and thought I could just get a switch with 2.5GbE ports and the 10GbE would just slow down to 2.5GbE. But after some reading, it seems that given when the X10SDV-TLN4F was built, 2.5GbE didn't exist, the 10GbE ports won't be able to adjust to 2.5GbE and will run only at 1GbE through a 2.5GbE port on a switch.

 

Looking around at switches (4-6 ports should be enough for me), getting an all 10GbE one would be very expensive and overkill. An all 2.5GbE would not speed up the X10SDV-TLN4F because of its inability to recognise 2.5GbE. There are some interesting switches (QNAP QSW-2104-2T-A and TRENDnet TEG-S762) that have two 10GbE ports and four 2.5GbE ports.

 

Then I found that there's a new type of connector, SFP and SFP+. Of course the X10SDV-TLN4F only has RJ45 ports. The switches that have SFP or SFP+ ports (for 10GbE) combined with 2.5GbE RJ45 ports seem to be significantly cheaper, but not so much so that getting some RJ45 to SFP adapter would be worthwhile. I've also read that these adapters are not always reliable. (The sole PCIe slot on the X10SDV-TLN4F is filled with an HBA card, so no PCIe card solution for me.)

 

If 2.5GbE going to be the mainstream standard for a while? How prevalent is SFP in consumer grade hardware? Don't recall ever seeing it other than on a switch. Should I plan for SFP in the future?

 

Is my best bet to go for the all RJ45 10GbE and 2.5GbE switch?

 

 

[MAM59]

2 hours ago, sonofdbn said:

when the X10SDV-TLN4F was built, 2.5GbE didn't exist

Still valid today, 2.5GbE does not exist 😁

Not kidding!

Your server will very likely work very well in a 2.5 only switch. This is because 2.5 is just 10 with one quarter of data and three quaters of pauses.

This is to give the old cable time to recover.

But you will have to turn on "flow control" on both sides (switch and server) so that the switch can tell the server which phase is data. It will slow down the server then to serve only the 2.5 part.

10G on RJ45 is usually tricky. You need very special cables and the energy consumption is really annoying.

Slowing down to 2.5 G relaxes both the cable needs and the energy waste.

 

To get real stable 10G and more you should move to fiber someday, copper is an overkill and it is very unlikely that it will ever go higher than the (risky) 10GbE now.

2 hours ago, sonofdbn said:

f 2.5GbE going to be the mainstream standard for a while

As already said: it does not exist.

After the 10GbE desaster (most connections do not work at all or are unstable after some times) they searched for a cheap way to rescue the RJ45 based LANS and decided to use the same methods but slow it down. So older and less picky cables and plugs (these are the real culprits, for many years proper 10G plugs did not exist at all, just in the last 2 years they have hit the markets but still there are a lot of wrong cables sold even today) could be used.

2 hours ago, sonofdbn said:

Should I plan for SFP in the future?

good idea! with SFP+ (note the +! without it you are limited to 1G again) or QSFP (40G and more) you are on the save side. You can use fiber modules or "direct attach" cables, both work well (DA only up to a certain lenght, but with up to 2m you are fine). Or risk RJ45 on short ranges or slowed down to 2.5

And, best of all, you can switch later if you decide to change media type someday.