Network layout - routers, switches, clients

[jamezm]

Hi. I'm very much a layman when it comes to networking but I'm trying to optimise my setup at home.

I have full fibre broadband coming into the house (but only at 300Mbps) to the Openreach ONT on the front wall. The house has a Cat6 cable run from that wall through to the lounge only. So I have an ethernet cable between the ONT and the LAN port on the front wall. I then have an EE smart router connected to the LAN port in the lounge. Due to poor WIFI performance in some parts of the house, I rely on Powerline (Devolo Magic 2 devices) to get network and internet access in the study.

I have a QNAP NAS (TS-251) in the study, as well as a desktop and PS5 and a couple of other devices, all connected to the network via Powerline.

If I wanted to maximise data rates in the study itself (i.e. for data transfer between the NAS and desktop PC, not necessarily for internet traffic), is there any advantage in using a decent switch in the study? For example, if I have a gigabit switch in position, with the NAS and PC plugged into that, would they see close to 1Gb data transfers between those devices or would the network traffic still be going (via Powerline) to the router in the lounge and back again? Would

I'm about to build a new PC which has an in-built 10Gbe ethernet port. Is there anything useful I can do with that? Any point purchasing a 10Gbe switch for the lounge?
The NAS has two ethernet ports. Could link aggregation help with this at all?

Sorry for all the questions! Hoping some of the experts on here can help me up the numbers. Thanks in advance.

 

[mickevh]

If I wanted to maximise data rates in the study itself (i.e. for data transfer between the NAS and desktop PC, not necessarily for internet traffic), is there any advantage in using a decent switch in the study?

Yes...

For example, if I have a gigabit switch in position, with the NAS and PC plugged into that, would they see close to 1Gb data transfers between those devices or would the network traffic still be going (via Powerline) to the router in the lounge and back again? Would

Just so. In packet switching networks, the traffic generally takes the shortest number of "hops" from source device to sink device. So with a switch interconnecting your NAS, PC and (presumably) powerline, (and anything else in the same locale,) the NAS---PC traffic "just" travels NAS---Switch---PC, never reaching the powerline plug at all.

This also has the added advantage that none of that traffic reaches the mains electricity circuit thereby freeing up capacity on the mains circuit for everything else that still uses it.

BTW - when you say "Powerline plug" - do you mean one with a single ethernet port, or is it one with multiple ports...? If the latter, it may be that the ethernet ports in that plug are functioning as a "built in" ethernet switch, but we' need to check the product description to be sure. (Some may be functioning as a "hub" which is slightly different, some my "only" have 100mbps ports.)

Little "desktop" 10/100/1000 (AKA gigabit) ethernet switches are really cheap these days - they can be found for as little as 10-20GBP.

I'm about to build a new PC which has an in-built 10Gbe ethernet port. Is there anything useful I can do with that? Any point purchasing a 10Gbe switch for the lounge?

I doubt it - to get any advantage from 10GBe, you really need dedicated infrastructure without powerline in the way and a use case that warrants 10GBe. Beyond "bragging rights" it's probably not worth the expense presently unless you want to get you geek on.

The NAS has two ethernet ports. Could link aggregation help with this at all?

Link Aggregation is about more capacity not more "speed." I liken it to adding lanes to a highway rather than increasing the speed limit. It allows us to convey more cars per hour, it doesn't avail any particular platoon of vehicles on any given lane to go any "faster," albeit that it can stop them being "slowed down" due to congestion when it gets really busy.

If you are going to buy a new switch, you might look for one that avails LA, (it needs both ends of the link cooperate,) though that will entail a more expensive "managed" switch that supports LA and some effort setting it up. Even then, having done so, for the sort of use case you describe, I doubt you'd notice much, if any, difference apart from you bank balance being a little more reduced.

 

[jamezm]

This is all VERY helpful - thank you! The bank balance is a factor but noticeable speed improvements around my network would make me feel real good.

BTW, at the study end, the Powerline device has three gigabit ports although I haven't been able to work out whether this acts as a hub or a switch: Amazon product

 

[mickevh]

I cannot see anything in the user guide or datasheet that asserts whether the powerline plug ethernet ports are switching or not. I tend to suspect they are, but I've no evidence to support this so I would proceed on the basis of skepticism.

You could try testing it - plug in your NAS and PC and either run a "speedtest" if your NAS is capable of hosting a speedtest app (such as NetIO or iPerf) or just simply copy some big files (like a DVD rip) between the two and do the maths (which is pretty much all that "speedtest" apps do.)

If you wanted to really get you geek on, you could try such tests whilst the plug "the other end" is not plugged in and therefore the powerline network is not active and see if it makes any difference.

If that does infer that the plug ports are switching, and performing decently, then adding and additional switch may not be any benefit unless you have "run out" of switch ports locally. But an additional switch won't make it any worse either (at least, not so as you'll be able to detect.)

 

[sebbelcher]

I'll second the opinion on the 10GbE, you have to have 10GbE accross your whole network to get any real benefit. Even if your PC has 10GbE and you buy a 10GbE switch, you'll still need to upgrade your NAS to 10GbE to unlock significant performance gains. Link aggregation is tricky to set up and requires config on both the NAS and the Switch and even if you get it all working correctly, you only unlock 2Gbps. There are some edge cases that will see improved performance if just the PC is on 10GBe, for example you could, in theory, be copying files between the PC and NAS at 2Gbps while simulanteously downloading to your PC at 1Gbps from the internet, but as your fibre is at 300mbps you won't see a huge improvement even here.

Save your money.

 

[tich77]

Um, ac

I'll second the opinion on the 10GbE, you have to have 10GbE accross your whole network to get any real benefit. Even if your PC has 10GbE and you buy a 10GbE switch, you'll still need to upgrade your NAS to 10GbE to unlock significant performance gains. Link aggregation is tricky to set up and requires config on both the NAS and the Switch and even if you get it all working correctly, you only unlock 2Gbps. There are some edge cases that will see improved performance if just the PC is on 10GBe, for example you could, in theory, be copying files between the PC and NAS at 2Gbps while simulanteously downloading to your PC at 1Gbps from the internet, but as your fibre is at 300mbps you won't see a huge improvement even here.

Save your money.

No, you wont get 2Gbps in this case, even with a 10GB nic in the PC. It will top out at the max throughput of one interface in the link, per application.
Where LA does provide a benefit is two - or more -clients connecting. Both clients will achieve close to 1GB throughput each, or - in theory - two copy jobs from the same PC to the same source. Note the "in theory", as it depends on a number of factors, not least what type of LA one is using.

 

[sebbelcher]

Um, ac


No, you wont get 2Gbps in this case, even with a 10GB nic in the PC. It will top out at the max throughput of one interface in the link, per application.
Where LA does provide a benefit is two - or more -clients connecting. Both clients will achieve close to 1GB throughput each, or - in theory - two copy jobs from the same PC to the same source. Note the "in theory", as it depends on a number of factors, not least what type of LA one is using.

Agreed, and if you're using spinning disks in the NAS (as most people do) your transfer rate will be limited by the read/write-speed of the disks well before it hits 10Gbps. The best home user NAS drives top out at about 180MB/s read and write speed, which is approx 1.6Gbps including some network protocol overhead, so if you upgrade to 10GbE you only get a ~1.6x performance improvement over 1GbE rather then the 10x most people expect.

 

[ChuckMountain]

No, you wont get 2Gbps in this case, even with a 10GB nic in the PC. It will top out at the max throughput of one interface in the link, per application.

That's not strictly true, it depends on how the application in question works. Some file copying software will do multiple connections and so can be routed over each link. Having said that it is much simpler (not cheaper) just to go for a faster single link.

 

[tich77]

Im not wholly sure thats accurate, either.
I think its down to the interface driver and stack. iirc Linux has a specialised drive that can split tcp streams and re-assemble out-of-order packets, but I have no details and have never used it.

Some of the performance measurement tools use multiple streams, but I (we, as in work) have never seen them manage to use more than 1GB in a LA environment.

Even using two different applications is no guarantee one will manage to use more bandwidth than that of a single link in the LA group, the switch's implementation/flavour of LA may preclude it.

Anyway, highly irrelevant

 

[mickevh]

For LA, it's down to the algorithm that's used to select which physical link to dispatch traffic along.

"Standards based" LA mandates that no additional "bits" should be added to the packets (robbing bandwidth) as they transit the link - so no adding some kind of sequence number or something (like Wi-Fi does) - and (IIRC) the packet order should (must) be maintained to avoid any out of order packet deliver.

One if the simplest ways to achieve this is to select the physical link on something real easy (fast) to compute repeatable. So, for example, something keyed on the MAC addresses of the packets - say the source MAC address, destination MAC address or even some hash of the two. To cite a trite example for a 2 physical link LA, it could be as simple as examining that last bit of the MAC Address and all "0" go down link 0 and all "1" go down link 1. (Until we get into failure or congestion states and "special" magic needs to happen.) The beauty of such as simple regime is it's easy to implement, meets to goal of no extra bits, no OOPD and works for all traffic types, not just IP.

Way back when I had some HP Servers that came with a "NIC teaming" drivers (before LA got IEEE codified) which would let one "play" with the link selection algorithms, e.g. based on MAC's as cited above, based on IP - though what it did for the none-IP traffic I don't recall - and some sort of "round robin" thing as well. None of the (mostly) 3Com and HP switches I've used to implement LA (switch---switch or switch---server) post IEEE ratification offered any controls over the scheduling - it "just worked." All I ever has to do to build them was tell the switches (and servers) which ports were participating in which LA. IIRC even that's been automated these days.

 

[oneman]

We have are virtually all enterprise Cisco HPE (actually Aruba) and LACP has some customisation available but to be honest it's more of a pain to set up compared to benefits. We actually use it for HA rather than performance improvements. I really won't bother with it at home unless you have extreme use case.

 

[jamezm]

All great technical info here, guys, thank you.

For my use case, would I be maximise my data transfers between PC and NAS if I simply connect an ethernet cable directly between them? They both have second ethernet ports so that could be set up as a second direct connection in addition to their separate feeds to the main network. Is that right?

 

[ChuckMountain]

Realistically it’s unlikely to make much of a difference in this case compared to both wired to the same gigabit switch. You would also need to give them a different IP address in a different subnet so the network doesn’t get confused.

 

[oneman]

All great technical info here, guys, thank you.

For my use case, would I be maximise my data transfers between PC and NAS if I simply connect an ethernet cable directly between them? They both have second ethernet ports so that could be set up as a second direct connection in addition to their separate feeds to the main network. Is that right?

Potentially yes, a direct cable would help. Use 10.x IP addresses and IP address for mapping the drive.

 

[oneman]

Wrong thread