Fibre network .... help

Granthar posted:

I have bought a couple of switches and media converters. One switch is linked to the BT router, the other is in the other room with my media server.

Across fibre that all works fine. When I plug in a media converter via fibre to the switch I cannot see my Naim Atom when it’s plugged into the media converter. If I plug my TV into the same media converter it works fine.

if I plug the Naim into the switch via Ethernet cable it works fine, yet when plugged into the media converter it doesn’t pick up an IP address. 

Am I missing something?

what is your model of media converter?   i had before the tp link mc110cs.   It worked fine.  I didn’t remember if it was mono mode or dual mode.  One of this modes doesn’t  work with naim streamer.

I have two, a Dlink mc220l and a Startech ET91000LC neither work. I have set the Naim to have a static IP address.

I suspect you are using gigabit media converters. Unlike most Ethernet devices, these usually are only compatible with other gigabit devices. Naim streamers run at 100MB, so you need 100MB media converters. 

I have got it working by replacing the media converter with a Cisco switch with fibre module and that now works. So I guess the issue is that the media converters don’t switch to 100mbs, strange that the TV works ok, I wouldn’t have thought that has a gigabit card

I think pretty much everything is Gigabit now. I suspect Naim choose 100MB because they are less electrically noisy, and it’s plenty for even Hi-Res music. I’ve been using SFPs in Cisco switches for a while now, and they seem to work well. 

Looking at the spec for the Dlink media converter the Ethernet port should auto switch between 10/100/1000

A couple of other brands of FMC that I’m familiar with are 100MB only, perhaps yours are different. Putting a switch between FMC and streamer then works, as the switch should autonegotiate between speeds where the FMC can’t. Still, if you have it working with SFPs in a switch, that seems a neater solution to me. 

Also tried my Muso QB and that wouldn’t connect either.

so I think I will use the media converter to connect my NAS

Granthar posted:

I have two, a Dlink mc220l and a Startech ET91000LC neither work.

Do you mean DLink? That  looks like a TPLink model number to me, and their MC220L is Gigabit only. So I still think that could be your problem, in which case using them for your NAS instead would make sense. 

Yep I meant TP Link.  

The fibre side is GB only, however the spec on the RJ45 port says
1 x 10/100/1000M RJ45 port (Auto MDI/MDIX), so it should switch to 100

Granthar posted:

The fibre side is GB only, however the spec on the RJ45 port says
1 x 10/100/1000M RJ45 port (Auto MDI/MDIX), so it should switch to 100

Then I suspect that whoever wrote that has messed up, because I’m pretty sure it’s not true. As I said, put a switch between the FMC and the streamer, and I predict that it will start working, as the switch will autonegotiate between speeds where the FMC can’t. 

https://www.tp-link.com/us/pro....html#specifications

That would be TP link then

I am sure that my TV doesn’t have a Gb Ethernet port, but that worked

Granthar posted:

Also tried my Muso QB and that wouldn’t connect either.

so I think I will use the media converter to connect my NAS

mc220 doesn’t work with naim.  Obsydian, member here, have tried and it didn’t work with his nova.  He took the same model as mine before, tp link mc110cs.

You have probably run into 802.3 autonegotiation issues... happens less often now, but funnily enough more common with commercial grade equipment... this is one reason why on managed equipment you can hard specify the speed and duplex parameters... I really wouldn’t recommend using media converters on the segment between Naim streamer and switchport.. unless you can run fully managed and inspect parameters like frame corruption and confirm duplex settings.

Simon, I know from many previous network threads that you are very knowledgable and well respected in this field,.

have to say , I didn't nderstand a single word of what you just explained, but keep up the good work of advising on network issues.

No worries.. quite simply when you plug ethernet leads between devices there is a low level link layer protocol exchange  that takes place just on that physical link.. it negotiates the parameters of that physical link between the two connected devices.. such as the streamer and a switch port, or streamer and fibre/twisted pair media converter. This automatic negotiation protocol establishes the link speed and duplex setting (ie where the link sends data in both directions simultaneously or one direction at a time). This automatic negotiation happens as the link becomes active, however if the two connected devices don’t negotiate correctly due to some network interface  incompatability, the link won’t come up at all, or will come up with a very high error rate and very poor performance

On consumer equipment.. it relies almost solely on plug and play and the link autonegotiation correctly working and  these days autonegotiation usually works. On commercial managed devices, one can usually manually set the parameters and disable the autonegotiation to allow correct link interworking for those rare cases where autonegotiation fails. Also usual practice for infrastructure connections is that these setting are manually set and locked down.

If you look at the Ethernet interface settings on Mac or PC for example, you will see the option to statically  set the speed and duplex settings for the link.. this is addressing this matter.

RFC 802.3 and all its elements, is the Ethernet standard.

Also it is this link layer driving its physical layer that is responsible for much of electrical RF noise side effect one can experience with Ethernet connections.

I guess in short use ethernet, it seems like a lot of work and extra equipment to run fibre and for what gain?

Quite...

Many thanks Simon for the comprehensive explanation. One of the key drivers for putting in fibre was to allow me to get rid of the Powerline adapters I was using between media server and rest of my equipment.

I went with fibre and as it would electrically isolate the Naim from the rest of the network.

Getting rid of powerline adapters is something you should be applauded for ????

However you really don’t need to worry about electrically isolating your streamer from the rest of your network... all compliant Ethernet adapters are galvanically isolated and protected to at least 1.5kV AC (@50 or 60 Hz) for 60 seconds.

Methinks Naim should be paying you a retainer for their equipment support????