Popular discussions about programming, compatibility and testing of optical transceivers.
I look after a small office network, one switch closet, and the four SFP+ cages on our access switch carry the 10G links to the server rack. It ran for months without a thought and now one cage is simply gone. TP-Link TL-SG3428X-M2 (V1), firmware 1.20.4 Build 20241104 Rel.40746, adopted in Omada…
Two SRX1500 sit in separate data centres a few kilometres apart, joined by dark fiber pairs we own end to end. They have to come up as a chassis cluster, which means the control link has to cross that fiber instead of a patch cord inside one rack. The setup: two Juniper SRX1500, identical hardware…
We have a dark fibre span of roughly 80 km where the owner will lease us exactly one strand - a second core is either not there or priced like a small building. Both ends terminate on chassis with XFP cages, and the service on top of it has to be 10 GbE. So what I need is a single-fibre BiDi XFP…
I am replacing the operator ONT with an SFP GPON stick on the Linux box that terminates our WAN, and the stick behaves nothing like a transceiver. Push it in and the cage stays silent for half a minute or more, long enough that I twice assumed the module was dead, and when the kernel finaally does…
Joining two campus buildings into one network. In building A there's an Avaya VSP 4400, and only 1G SFP ports are free there: the dedicated uplinks have long been taken for other purposes. In building B there's an Extreme Summit X690-48x-2q-4c, and there only 10G SFP+ ports are free, no other…
We run a pair of racks that hand off to a carrier-facing Cisco NCS, and one of the 100G server uplinks has never come up since the build. Same result after moving the server to another cabinet with a different patch panel, so I have stopped treating it as a one-off. Supermicro server…
Small office, two buildings, and all I want is a plaain 1000M fibre link between the racks. Both ends are configured for 1000M, both stay dark, and this has been dragging on for weeks now. TP-Link TL-SG3452P, hardware V3, firmware 3.20.4, link taken from one of its SFP cages PLANET IGS-6329-8UP2S4…
A short no-name DAC between a UDM SE and a Minisforum MS-01 had worked for months; a new 30 m Ubiquiti UACC-AOC-SFP10-30M active optical cable was recognised by the UDM SE (vendor, part, serial, temperrature, power visible) but no link came up and the SFP port log showed an SFP EEPROM error; on…
The poster wanted to connect a UDM SE (10G SFP+) to an Enterprise XG 24 switch (25G SFP28) and asked whether an SFP+ DAC would work with the SFP28 port falling back to 10G, or whether an SFP28 DAC was preferable. The concern was whether the SFP28 cage would fall back to 10G with an ordinary SFP+…
A Meraki MX95's WAN2 SFP would not link to an upstream Extreme switch, while the same SFP and patch linked to a Netgear switch, which in turn linked to the Extreme. The same happened with an MX85 against an AT&T-provided Ciena device. Cisco-certified and Extreme-certified SFPs were tried in all…
I look after the access layer at a small ISP and I want our two GPON OLTs to show up in monitoring the same way everything else does. The wish list is not exotic: how hot the chassis runs, CPU and RAM load, counters per port, and the part I actually caare about, the optical side. That means Rx/Tx…
I look after a small office network and put in a DrayTek VigorSwitch FX2120 to get a 10G core. Both 10G links, to the router and to the NAS, came up on their own within seconds. What I cannot do is get a single 1G device onto the switch through the SFP+ cages. Switch: DrayTek VigorSwitch FX2120…
Trying to replace the ISP terminal in my home rack with a GPON stick straight in the router, so the fibre lands in one box instead of two. The stick is recognised, and that is where the good news ends. Turris Omnia on Turris OS 5.0.3, stock kernel Huawei MA5671A GPON stick with unlocked firmware…
We are bringing up a pair of 8360-32Y4C as leaves and the downlink plan is deliberately mixed: mostly 25G to servers, a couple of 50G ports to a compute chassis, and a few slow copper drops for out-of-band gear. Because the SFP56 downlinks are grouped and the speed is set per group, I want to…
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…
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…
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…
A site decommission left me with a drawer of pulled Cisco optics, a mix of GBICs, 1G SFPs and 10G SFP+, and I have to decide which of them go back into production and which go in the bin. The GBICs I have put aside for now, since nothing on the bench takes them, so everything below is about the SFP…
