zhongfu's inane ramblings

still haven't gotten this shit to work so i've been forced to do some relaxing nighttime reading (/s)

new toy just arrived

the funny chinese OpenWrt firmware also broke SFP DDM output somehow, so I stopped being able to see metrics like tx bias/rx power/SFP temperature

but it's OpenWrt, so you could just install snmpd and write your own script to expose those metrics on a custom OID

swapped out the ufiber-instant for the huawei MA5671A (with a funny chinese OpenWRT firmware), and now i'm able to link up to the ONU stick at 2.5Gbps

well, it could be better, I guess? not sure if i'm being bottlenecked by this cheap-ass ISP, or by the ONU stick

oh boy i found two random GPON SFP sticks at home (and also another one without an integrated MAC, which would be kinda useless)

these Lantiq ones run a bit hotter but can do 2.5G HSGMII out of the box, so maybe I'll swap out the current one for one of these

spent the last 50 minutes tidying up random bits on my storage server:
- take out the (failed, replaced) 12TB hard disk that was in my main zpool
- swap out the PCIe switch-based 4x m.2 <-> x16 PCIe adapter for a cheaper, faster, and more power efficient one relying on bifurcation
- the new m.2 <-> PCIe adapter has a pretty beefy heatsink, so i'm adding back the 512GB PM981 that I took out because it kept... overheating?
- swap out the flakey old 480GB SATA boot SSD for a 4TB SSD i had lying about

my sleep will suffer but at least I got a bunch of the stuff I've been meaning to do out of the way, and now my main zpool doesn't have to limp along with only 2 special vdevs

perhaps I can also use the 4TB SSD i just popped in as temporary torrent storage, so I can actually saturate my internet connection downloading my chinese cartoons

the reason why I had that jerry-rigged jumper cable setup was because some asshole at APC decided to use a different DB-9 pinout for serial, so plugging a normal DTE null modem cable will cause the UPS to shut down immediately

no prizes for guessing how i figured that out...

forgot to take pics but i just finished replacing the dead batteries in my UPS (an APC smart-ups 1000/SUA1000I), and also tweaked the voltage reading offset so it doesn't kill my batteries prematurely with an unnecessarily high float voltage

at 37.8degC internal temp, it's currently floating the battery at 27.13V (and the internal readings report that too -- surprisingly accurate!) that's around 2.2608V/cell

battery university recommends 2.25V to 2.27V per cell, with -3mV per cell per 1degC above 25degC. UPS internal temps can get above 40 degrees for mine, so that'd be an ideal float voltage of 2.205-2.225V/cell, or 26.46-26.70V for the 2x 12V batteries in my UPS

for now, I've tweaked the internal voltage calibration to read 0.4V above the actual voltage (so 27.13V would correspond to ~26.72V). hopefully that keeps my batteries alive for a bit longer, these things aren't too cheap

now it's time to poke into the ONT for my first broadband line, ft kinda menacing error message

provider for my second broadband line gave me a used ONR with over 2 years of DHCP lease history and a thin ass fiber optic cable, you get what you pay for i guess

no more wasting space

i still have 10 free SFP+ ports and 1 free SFP28 port on my router, so i could totally get a third and fourth broadband line (but the cpu will probably die way before then)

hoping i can manage to get the xgspon onu stick working too (bonus points for exposing the VoIP VLAN + figuring out how to dump the VoIP credentials), then i'd be able to remove a second power brick and all that

in the meantime, my second broadband line is using a ufiber-instant

wouldn't recommend it:
- laser driver is some proprietary thing, so you're stuck with using their kernel
- because you're stuck with their kernel, you don't get 2500Base-X support
- because you're stuck with their kernel, you get wonky SFP EEPROM data (emulated with a kernel module, claims it supports every link speed under the sun... which it doesn't, so it'll break autonegotiation)
- because you're stuck with their kernel, some of the PON parameters (e.g. what it advertises to the OLT...?) might not be changeable

but otherwise i guess it works pretty ok, and i had these lying around anyway... these things do run hot tho

i have succumbed to the temptation (and also bought a 2.5GbE GPON ONU stick for my second broadband line)

as it turns out, they (a chinese company) let you ship to china for free if you ask nicely, and it's kind of not a terrible price at $160, so...

in other news, i'm trying to convince myself not to buy this (as an experiment to see if I can replace the bulky-ass XGSPON ONT with a single SFP)

I would also, in theory, be able to hook up Asterisk or something to their internal VoIP server too (for home voice), instead of being forced to get a POTS phone

i still think the FTTR thing is a bit stupid though, for $500+ you can buy a shit ton of cat6 cables, and it's not like you're gonna be staring at your ceiling enough to be bothered by the cables anyway. but i guess it's good if it stops people from using mesh WiFi APs

cool video, dude set up a (lab) DOCSIS 1.1 cable broadband access network with gear from two decades ago

https://www.youtube.com/watch?v=4ko7Kipc-Zc

i think it'd be pretty fun to mess around with something similar like GPON and run actual traffic on it, but doing it at home is kind of dumb — OLTs and ONTs are pretty expensive on a small scale, and GPON can be kinda troublesome to maintain too, especially compared to plain 10G optical Ethernet. on a small-to-medium scale though (like for a building or housing development), now that'd be kind of interesting

with that said, some ISPs are effectively GPON-at-home ("fiber-to-the-room"). for a nice chunk of money, you get a kinda-OLT to which you connect your slave FTTR nodes. you'd be limited to 2.5G/1.25G shared across all nodes, but I guess it works great if you don't already have Ethernet to each room, since you can just hook them up with a single strand of "nearly-invisible" plastic optical fiber from the master node, laid along the edges of the wall.

swapping out the LTE modem in an OpenGear ACM7008* serial console server/LTE gateway out for a EM7565

this thing is a serial console server with:
- 8x RJ45 rolled "Cisco" serial ports (no need for straight-through cables, normal Ethernet cable will do)
- 4x USB ports (for... USB UPSes and the like, I guess)
- an LTE modem (with 2 SIM slots), and
- two Gigabit Ethernet ports for uplink or whatever

I got one for fun, so that I could have out-of-band serial console management for my router and switches (and KVM and servers and...) without having to trudge over and plug in a lame adapter and whatnot

LTE modem would be nice as a fallback for (OOB?) management traffic (or other important traffic, if needed, but nothing I run is really that important anyway)

but well, you see, I buy all my crap off eBay, so this thing naturally came with an LTE modem that somehow supports none of the LTE bands used in Singapore. (it's a Sierra Wireless MC7354, if you're interested)

thankfully it comes on a weird lil USB carrier board with a mini-PCIe slot and two SIM slots, so I could just swap out the modem

unfortunately they didn't have support for anything other than Qualcomm's QMI (like MBIM), so the spare Fibocom L850-GL I had (with an Intel chipset) didn't really work, and I sold the last Sierra modem I had, so I had to buy one off Taobao

well, for some reason, the miniPCIe modems are quite a bit more expensive (and most manufacturers have moved on to m.2 anyway), but that's not an issue if you can fit a miniPCIe-to-m.2 adapter and MHF-4 to u.FL adapter for the antenna connection into wherever you're using it. that's what I did back when I was using a ThinkPad X230 anyway, then I realized I didn't have too much of a need for LTE on my laptops, but I digress

in this case, the u.FL to SMA antenna cables here are removable, so I also picked up some MHF-4 to SMA cables to avoid having unnecessary bits here

I'm halfway through replacing the modem now, so the new antenna cables are now installed, and both LTE modems are out. the crappy MC7354 is in the bottom left, the EM7565 is under the corner of the console server. this should be pretty uneventful anyway -- I see no reason why the EM7565 wouldn't work, since newer SKUs of this thing come with the EM7565 and other newer m.2 Sierra modems