What does the optical modem (LOID) mean? At the registration step of the light modem card, this string code is the broadband ID card

last week, I went to my cousin's house to replace the cat. My old cat kept disconnecting after more than five years. The technician came to replace it for free. After the cable was reconnected and halfway through installation, he asked, "Your LOID should let me know." My cousin was stunned— stickers had long been soaked and soaked, the broadband installation order from back then was impossible to find. When the call reached me, I remotely led her to pull up the code from the optical modem backend, and it took about two minutes.

sort out this while it's hot." It looks like twins from the SN on the sticker, and the work it does is completely different. If you mix it up, switching cats can be a hassle all afternoon.

clarify first: this certificate is issued for broadband, not for machines

LOID The full name is Logical ONU ID, which translates to Logical Identifier. On the day you open a broadband account, the operator's data center assigns you a string of characters—about ten or twenty characters—that's the LOID. Some provinces print it on optical modem stickers under various names—"broadband identification code," "logic ID," "logic authentication ID," all referring to it.

key lies in the three words: "Who to follow." SN is the factory serial number, which follows the machine; LOID is the broadband logo, following your broadband. to use an analogy: SN is like a VIN—the machine is welded shut out of the factory, so if you change cars, it will replace the other one as well. LOID is like a license plate; you apply for it at the vehicle management office (operator). When the old car is scrapped, the plate can be removed and installed on the new car.

the word 'logic' comes from this too. SN is a physical identifier, facing the machine as a physical entity; LOID is a logical identifier that exists only in the data center account data and is a virtual number. Machines burn, drop, or replace them, physical numbers disappear along with them, but logic numbers are fine—like a car scrapped with license plates still hanging at the vehicle management office, you can buy a new car and replace it.

so if the modem breaks, buy a new and the machine's SN changes, it's okay—just add the original LOID to the new modem, and the data center will still recognize you. On the other hand, if you try to change the cat's SN with LOID certification, it's a waste — they don't even check the SN.

the registration step, the data center is using the roster to check the names

Many people have seen the ShinKong modem's PON light flash slowly for a long time without staying on, but at that moment, it was actually waiting in line at the data center entrance to shout. The entire registration process consists of three steps: after powering on, the optical modem reports "I am XX number" (i.e., LOID). → the OLT device in the data center opens its roster to check this number. →Once found, it is issued the configuration for this household. Your broadband account, IPTV VLAN, and voice parameters are all included in this package, and then the PON light turns on steadily.

LOID The result of filling in the wrong information is that the roster doesn't show this person: the PON light keeps flashing slowly, and even if you restart ten times, it won't help—it won't even get through the door. This is two different issues from major light degradation and fiber breaks—if the optical path is faulty, LOS lights will turn red; if registration doesn't recognize LOS, LOS will turn off; if the PON flashes vigorously, you can tell by the light. I previously wrote a detailed on PON registration. If you get stuck in registration, you can check it.

By the way, some provincial data centers recognize SN or a string of passwords instead of LOID, so the way to switch cats is different: either rewrite the SN of the new cat with the old one's (the Enshan forum's folk remedies, beginners should avoid it), or call the carrier to have the backend rebind. First, figure out which type your family recognizes before making a move.

the three brands have different approaches

among the cats I've helped replace, the tempers of the three are quite different. Most telecom companies recognize LOIDs, and some even require an additional LOID password; Most mobile regions use Password authentication , which doesn't use LOID at all—it's just a string of password characters; China Unicom is a bit economical: some recognize LOID passwords and leave them blank, while others simply bind SN.

Out of ten online tutorials, nine assume you recognize LOID. Mobile users just follow the instructions and get it wrong—it's not your operation wrong, but the question changes. I previously wrote a separate article about the complete comparison of registration for the three Huanmao listing the recognition method, placement, and who to ask for, just following your own carrier's line.

this string of codes is lost, the four roads can be found

My cousin's sticker sticker is not an isolated case; the weak current box gets damp, moves are torn off, and the writing is worn off—it's all too common. Don't rush, try the four paths in order:

the first step, flip the sticker. get close to look for words like "broadband identification code" or "logic ID," and when the phone flashes at an angle, sometimes the blurred text can be mostly recognized. Take a photo and zoom in on it in the album—it's much better than just sticking a weak current box against the naked eye. That's how my cousin's family identified the top few and then checked it with the backend. Not every device prints it; some Huawei models print, some ZTE prints but some don't. If you can't find it, just leave the next line.

the second rule, turn the light modem backend. Telecom's Cat browser, type 192.168.2.1, log in with the useradmin account on the sticker ( password forgot to retrieve the ), go to 'Network' and find 'Remote Management', and inside you'll find a 'Logical ID Authentication' page. Your LOID is lying in that input box, and you can see the whole string at a glance. Regular account permissions are enough, no need to touch the super password. My cousin carved out this very path.

Third, the reloading machine record. the work orders left by broadband installers and activation SMS sent back then, many provinces had identification codes written on them. Search for the word "broadband" in your phone text message.

Fourth, call customer service. provide the installation address and the owner's name, and the customer service backend can check it. This is the safest option—you have to wait in line for labor.

three pitfalls: mutual kicking, reset clearing, and having someone else's code in the second-hand cat

the first pit where the old cat is unplugged before swapping cats. In the data center, only one optical modem is allowed to operate on the same LOID device. If both the old and new devices are powered on via fiber optic cable, the later one registered and online will kick the earlier one off, kicking each other back and forth, resulting in both phones fluctuating and PON lights causing issues. The method is simple: just unplug one fiber, and if the other immediately stabilizes, then the two are kicking each other without escape. The correct order for replacing a new device is: power off the old cat and unplug it→ New cat fill out the LOID →, wait for it to register and stay on, then decide whether to keep the old cat.

the second pitfall: restoring the factory will clear out the manually filled LOID. Press Reset, and the machine returns to factory state. The authentication information you entered yourself disappears. So before restoring the optical modem from the factory, copy the LOID and store it on your phone, otherwise you'll have to go through the four steps mentioned above to find it again.

the third pitfall, the second-hand optical modem might still have a LOID from the previous brand. If the seller hasn't restored the factory before selling, and the machine still has their code, it's common for the server center to find no such person after buying and registering it. Once you get it, first clean it out of the factory, then fill in your own. On Xianyu, there's a kind of 'registered, plug in, and use' machine. Basically, the seller just enters the code for you. It's easy to save trouble, but the principle is the same.

just follow the instructions and follow them

and sort through the order again: first, use stickers or backend to find the LOID and copy two copies to store them; Old Cat Power Cut Off and Offline Line; Enter the 'Logical ID Authentication' page on the new cat and save it; Waiting for PON to switch from slow flashing to steady on usually takes a few minutes; Finally, take a photo of the new cat's sticker and save it in the low-voltage box photo album, so you won't have to bother with it again next time. This code is rarely used, and when needed, without it, the internet can't be accessed—it's worth spending two minutes to set it aside.