Sonore opticalRendu

[Miska]

On 1/3/2019 at 11:53 PM, Foggie said:

I don't recall the exact issue, but several of us using optical had a few quirks with a speed issue ("too fast") using NAA with microU (I think) which was remedied very nicely with a 10/100/1000 FMC - this Trendnet that @jabbr recommended.  I believe @The Computer Audiophile had a similar issue and used a dumb 10/100 switch to address the too fast issue.

 

Root is that if your network gear (switch, etc) doesn't support 802.3x (flow control) spec, then you will likely have issues.

 

On smart switches you practically always have a configuration option for this feature, whether it is enabled by default is about 50/50 these days. If it is disabled, the smart switch usually discards flow control packets which causes buffer overflow at receiver which cannot manage full network speed (for example iMX6 SoC is internally limited to about 400 Mbps), which in turn causes lot of re-sends which in turn makes situation just worse. So overall, first thing to look is that network gear supports 802.3x, and secondly don't assume that smart (configurable) networking gear is plug-and-play. For managed/smart switches you will need to configure it properly or otherwise you will have problems. If you are not familiar with intricate details of network configuration, it is better to stick with unmanaged switches that state support for 802.3x (flow-control).

 

[Miska]

2 minutes ago, ericuco said:

Here is an unmanaged switch that I have been using for some time in my system that supports 802.3x.

 

Diablo Cable - Dual SFP Slot Media Converter with Dual 1000M Ethernet Ports

 

I'm using these as unmanaged switches:

https://www.zyxel.com/products_services/gs1100_series.shtml

(just don't get the smallest one that has high heat production and wallwart PSU)

 

And HPE 1420 series unmanaged switches:

https://www.hpe.com/us/en/product-catalog/networking/networking-switches/pip.overview.networking-switches.7091214.html

 

Both are very reasonably priced. In addition to per-room unmanaged switches, I have four managed switches around the house to deal with things like VLANs (802.1Q).

 

Both support the features I require:

802.1p

802.3az

802.3x

 

802.3az associated with cable length detection makes sure the switch is not putting unnecessary amount of transmit power on a copper cable. Preferably the network interface at the other end should support 802.3az too to get the low power link states activated too.