Popular discussions about programming, compatibility and testing of optical transceivers.
I finally moved my VDSL2 line off the ISP box and terminated it on the Turris Omnia itself, mostly so that PPPoE runs on the router instead of on a second device in bridge mode. The setup part was pleasant: seat the stick in the cage and the WAN interface simply moves onto the module, leaving the…
The poster asked whether a 10G SFP+ SR or LR optic in one switch can auto-negotiate down to 1G to link over fiber with a 1G SFP in another switch, and if not, how to attach a handful of 1G optical connections from a 1G switch to a 10G switch. They understood that Cisco SFP+ optics run only at 10G…
Standing up 25G uplinks from a QFX5120-48Y towards a second switch and a couple of new servers. Before I hand the segment over I want the link settings written down properly, and I cannot find where auto-negotiation lives on these ports. Juniper QFX5120-48Y 25G optics in the SFP28 cages et…
We are lighting a handful of channels over one metro pair with passive mux and demux at both ends, 100 GHz plan. Everything I can actually source is fixed-wavelength DWDM SFP+, a separate part number per channel, and keeping spares that way is getting silly. 10G aggregation at both ends, SFP+ cages…
Joining two buildings over a Nortel pair that has been in place longer than I have. The plan was simply to light the existing house fibre between the two switches and be done with it, but port 23 will not come up on either end. Two Nortel ERS 5510-24T, software 4.0.2.02 1000SX SFP GBICs, one in…
The poster needed to connect a MikroTik CRS328-4C-20S-4S+RM to an HP 1820-24G-PoE+ over 200-500 m of outdoor aerial fibre and asked which SFP modules to buy and how to verify compatibility before purchase. The HP compatibility table listed only J4859C as a single-mode SFP, while MikroTik offered…
We hand customer circuits off on MRV OptiSwitch demarcation boxes - mostly OS906, with a few OS904 and OS912 left on older builds. When a ticket comes in about a circuit that is down or flapping, I want two things over SSH before anyone drives out: what module is actually sitting in the port…
An embedded device with a 10GbE SFP transceiver kept logging power warnings above 800 mW and occasional errors when fed by an NVIDIA/Mellanox MMA2P00-AS 10/25G transceiver over a 2 m OM3 LC patch. The poster assumed transmit power is negotiated between the two ends and asked whether a failed…
I look after a two-building site and the access switches were replaced with Aruba 2540s a while back. The fibre between the buildings has not been touched, but since the swap the uplink refuses to come up. Aruba 2540 on our side, ports 51 and 52 used for the uplinks Aruba J4858D 1000SX in the 2540…
A link between two of our sites: about 27 km of single-mode fiber, MES3324F on both ends. Installed a pair of 1550 nm FANG HANG SFPs sold as 40-km modules. The link comes up, lives for a few dozen seconds, and drops, over and over, until the port gets blocked. 2 x Eltex MES3324F, firmware 4.0.7 SFP…
We had a 200 m OM4 backbone pulled between two buildings a while back and I am trying to light it with kit we already own. Both ends are 2530s, both modules are the HPE part, and the link simply will not come up. 2x Aruba 2530-48G 2x J4858C 1000SX, port 51 on each side roughly 200 m of freshly…
I swapped the ISP ONU for an ODI DFP-34X-2C2 GPON stick in my Turris Omnia so the fibre terminates in the router instead of another box on the shelf. That part worked: the line is registered, traffic flows, no complaints. The problem is the rate. It never goes above 1Gbps, and 2.5G was the whole…
We are a small regional ISP rebuilding the optics budget for next year. Every 10G spare on our shelf is coded for exactly one platform, so the spares pool is roughly three times larger than our failure rate justifies. The idea on the table is to buy re-codable modules and code them ourselves as…
A network operator received QFX3500 switches that would not bring up thhird-party SFP+ transceivers even though a Juniper sales engineer had said they would work. JTAC stated that non-Juniper SFP+ optics would never be supported on the platform. The switch detected the presence of the module but…
The poster asked how to test fibre cables from a switch. The guidance covers reading optical levels with show interfaces transceiver / show controllers, comparing TX and RX at both ends, and recognising that a reading of -40, -50 or -80 dBm means no signal is being received. Hardware involved…
