A while ago I got into the rabbit hole of fiber optics sticks. To put a really long story short, my fiber Internet provider uses custom modems to convert optical signals to, well, regular ethernet. Usually it's fine for most people, but I hate having to use multiple modems and routers to do the job that a single router can suffice. Not to mention that most useful features of the ISP's modem is locked-down...
When I heard about the existence of XPON ONU sticks, I was ecstatic. It is clearly the solution to all my headaches with my ISP! Unfortunately my ONU stick does not use the ethernet interface, but rather exposes one SFP port. And routers with SFP ports are not exactly cheap...
Until I found the Ubiquiti EdgeRouter X-SFP. Anyway have you gone on a really long tangent before?
EdgeRouter X-SFP: What is it
Well, it's a router with one SFP port and 5 gigabit ethernet ports that supports passive PoE. More on that later.
It is probably the cheapest SFP router available on the market, and I got mine for ~40 USD. Nonetheless, it does not feel cheap at all! The outer shell is very well-made, and the steel only gives it a more polished and industrial feel. Its design and manufacturing is pretty much flawless.
And yes, this is a router, not just a switch. This means you can do all sorts of Layer-3 goodness: create a LAN, have a DHCP server, setup firewall rules, all that stuff. You can also technically use it as a VPN router.
Now Let's get into the details. Firstly, yes, it has only one SFP port, and it does not support SFP+. This means it bolsters an uplink speed of 1 Gbps maximum. And about those 5 ethernet ports? They are all indeed gigabit, except a few caveats.
Now about its hardware: it's not too shabby for a router that's already a few years old. It boasts a MediaTek MT7621AT dual-core CPU with 4 threads in total. The RAM is 256MB of DDR3, and the internal flash is also 256MB. Not too bad! Also worth noting is that this CPU supports hardware-accelerated NAT and flow offloading, so the routing itself does not slow down the CPU cores at all.
You can also switch the EdgeRoute to "switch mode", in which it functions as a managed switch.
Sure this router seems pretty good for its bucks (and it is), there are a few quirks and caveats that you need to know about. Firstly, the routing throughput is apparently limited to 500/500Mbps, across the entire device. So bidirectional 1Gbps routing is essentially impossible.
And more, the ethernet ports have passive PoE with 24V outputs. If PoE is enabled accidentally for unsupported devices, it will cause damages.
The stock EdgeOS for this router is pretty good... But I'm an OpenWRT fan, and (fortunately) this router supports OpenWRT! Flashing it requires two steps, and you need to upgrade its bootloader before flashing, but it's nowhere near the league of having to reflash the NAND.
And yeah, after OpenWRT is up and running on this little machine... Pretty much anything is possible, including PPPoE, VLAN, etc. I managed to get ~900Mbps download speed with the VLAN+PPPoE setup that my ISP uses. And routing latency is always sub 1ms as well.
One tiny problem though: I did not manage to setup IPTV correctly. It simply won't work for whatever reason. Not sure if that's a problem with the EdgeRouter or my ONU stick, but I'm suspecting it's the latter.
I mean... you can run VPN on this router? Sure the stock firmware doesn't support Wireguard, but OpenWRT supports it just fine. It's just that this CPU has no
AES instructions, and while Wireguard uses
chacha20-poly1305 cipher, the CPU itself is simply too slow. 100Mbps might be possible, but yeah...
I did not encounter any crashes with this router so far. My ONU stick, on the other hand, did crash for a few times. One problem I noticed with OpenWRT is that sometimes the whole system would freeze after changing network interface settings. Usually it clears out after one reboot, but I haven't figured out its causes so far.
The Ubiquiti EdgeRouter X-SFP is perhaps the cheapest router with SFP port and PoE. It is pretty reliable for home use, but its gigabit ports and its routing speed limitations really limits its potential. But on the other hand, it supports OpenWRT, so the customization possibilities really is limitless.