AS6. Problems connecting to the network

Alessandro65

Good evening everyone, and thank you for welcoming me to the group.
My name is Alessandro, and I'm writing from Italy.
I recently purchased an LHY AS6 network switch. I'm having some problems connecting to the network. Before explaining what's happening and what I need to do to get the AS6 to connect to the fiber, I'll explain (in a simplified way) how part of the digital section of my stereo system is composed.
I stream exclusively via Qobuz, which runs on Jplay Femto, which is present on my music server. To reach the music server, the line originates from a Vodafone router, into which the fiber optic cable enters. From the router, I use an Ethernet cable connected to a Cisco Business switch. From the switch, I use an Ethernet cable connected to a low-cost FMC containing a Finisar SFP 1318 1 GB module. From this module, I exit with a single-mode fiber cable to a second FMC (now replaced by the AS6) containing a 10 GB Finisar 1475 SFP module. From this, I exit with an Ethernet cable connected to the JCat XE network card in the music server.

Since I inserted the AS6 in place of the old, inexpensive FMC, the 10 GB Finisar 1475 SFP module has been having difficulty connecting to the network that connects it to the FMC located near the router, which contains the 1 GB Finisar 1318 SFP module.

In fact, as soon as I turn on the AS6 network switch, the green light next to the Finisar 1475 SFP module flashes continuously and does not connect to the network.
If I remove the SFP module while the AS6 is on and reinsert it, the green light stops flashing and stays on, so the AS6 connects to the network and allows me to listen to music.
Why do you think this happens?
Is there a procedure I should follow when turning on the various digital line components to prevent this from happening?
Thanks to anyone who can provide helpful answers.

Jayce

Alessandro65

Hi Alessandro,

Welcome to the group.

From your description, this looks more like an SFP speed/compatibility issue than a power-on sequence issue.

The AS6 SFP port is a 1G SFP port, while the Finisar 1475 module is most likely a 10G SFP+ module. On the other end, your FMC is using a 1G Finisar 1318 module. Optical Ethernet links normally need both ends to run at the same line rate; a 10G SFP+ module and a 1G SFP module are not a reliable pair.

The fact that it sometimes works after removing and reinserting the module suggests the module is being re-initialized after the AS6 has finished booting, but this is only a workaround and not a stable solution.

I would recommend using a 1G single-mode 1000Base-LX SFP module in the AS6, ideally the same type as the other side, such as Finisar FTLF1318P3BTL, or another compatible 1.25G 1310nm single-mode SFP. Insert the SFP modules before powering on the devices, then power on the router/Cisco switch/upstream FMC first, then the AS6, then the music server.

But the real fix is to use 1G SFP modules on both sides.

Alessandro65

I swapped the Finisar 1475 SFP, moving it to the upstream FMC (router side). I installed the 1318 in the AS6. Now everything works perfectly. I don't know how much I'm losing in terms of sound with this change, but I don't think I have any alternatives.