What sets of parameters should be copied before changing to a optical modem? LOID is not everything. If you miss VLAN and voice, you will still be unable to access the Internet.

Last month, I complained that the old optical modem sent by China Unicom only had a Gigabit port, so I received a new modem from ZTE with a 2.5G port. Before he started, he called me specifically and said that he had taken a photo of the LOID on the sticker on the back of the old cat, and asked me if I could just plug in the optical fiber and fill in the code. I say don't rush to unplug the optical fiber. LOID is just one of them. If you miss the others, you still won't be able to register. He didn't listen. When he plugged it in, the PON light changed from flashing to steady on, but the registration progress on the management page stopped at around 40%. The broadband connection was not working, and the landline phone didn't ring either. He didn't call back until 11 o'clock in the evening.

Later, I even went into his WiFi and checked the old cat backend, only to find that he didn't copy the VLAN of the broadband connection, the voice connection of the fixed line, or the SN and MAC of the old equipment. The reason why new cat registration is stuck is not because the machine is broken, but because the operator's computer room is waiting for another set of parameters. This article explains how I got it back that day and which set of certificates China Telecom, China Unicom and China Mobile recognized.

First, distinguish between the three authentication methods. Don’t use LOID as a master key.

After the optical modem is plugged into the optical fiber, the first step is OLT certification. The operator must confirm whether the modem is a device allowed to go online in their inventory. Different provinces and different operators use different certificates, so don’t just copy them when you see LOID mentioned online. Based on my own experience and that of several family members around me, I compiled the rules that three families often encounter into the following table.

I want to say one more thing about moving. I have never replaced a mobile optical modem myself, but I have dealt with one for a colleague. His province identified Password, which is a string of broadband passwords, not LOID. Friends from another province also said that they recognized SN. Therefore, don’t follow China Telecom and China Unicom’s habits for Mobile Cat. First, check whether the authentication page in the old Cat backend says LOID, Password or SN. I will write down the complete process of registering Mobile optical modem when you buy it yourself. The mobile optical modem is broken. How do I register it if I buy one myself? Here, this section only talks about the idea of ​​copying parameters.

Where should I copy the LOID? Don’t panic if the sticker is sticky

The LOID is not printed at a fixed location on each Optical Modem. I have seen stickers become soaked or torn off, and I have also seen ordinary accounts not displayed in the background. For optical modems of China Telecom and China Unicom, the most stable entrance is to use a super password or a normal account to enter the backend and look for the "Device Information" or "ONT Authentication" page. The LOID is usually written as a series of numbers, with a dash in the middle, or two lines separate from the password.

If you really can’t get into the old cat backstage, look at the bottom sticker first. Some LOIDs will be printed on the stickers, and some will only print the SN and MAC. The stickers do not need to be checked in the operator's app, or the installation and maintenance technician calls to ask. When the old cat is still lit, this step is much easier than checking after the new cat is obtained, because when the new cat cannot be registered, you may have pulled out the old cat, and by then it will be too late to get in. What exactly does the LOID code represent, and whether it is related to broadband or machines, I will break it down and write it in What does optical modem LOID mean? , I won’t repeat it here.

I helped Fa Xiao find his LOID by entering his old cat. 192.168.1.1 In the background, I took three screenshots of the device information page in "Status": One LOID, one SN, and one MAC. The order of screenshots is not important, the key is to keep all three.

VLAN and 802.1p priority are more important than imagined

The small new cat is stuck at 40%, and the LOID is actually passed. What stumps him is the subsequent issuance and dialing. In the "Network" or "Broadband Settings" of the old cat background, each WAN connection has a VLAN ID. Common values ​​for China Telecom and China Unicom's broadband are 41, 45, 46, 4001, etc., and each province is different. This number is copied incorrectly. After the computer room identifies the device, your PPPoE dial-up is unable to connect.

There is also an 802.1p priority next to the VLAN, which is generally 0 by default and 5 or 7 in some provinces. When changing the bridge or changing the modem, this value should remain the same as the modem, do not reset it to zero. I have seen someone copy the VLAN correctly and change the priority to 0. As a result, the dialing is occasionally connected and disconnected. I checked it for an afternoon before looking back and saw this box.

In addition to the broadband connection, there are usually several IPTV, TR069, and voice connections in the backend of Optical Mode. People who change bridging are most likely to only focus on the INTERNET one and regard everything else as useless. In fact, IPTV has its own multicast VLAN, and the voice connection has a SIP account. TR069 is the operator's remote management channel. If you delete it incorrectly, the set-top box will have a black screen and the landline will have no dial tone. How to recognize these connections, which ones can be moved and which ones cannot be moved, see What are INTERNET, TR069, IPTV and OTHER in the backend of optical modem? , more detailed than mine.

Landline and IPTV are the two groups that are most likely to be leaked. If you leak the same, someone will come to you.

Nowadays, fewer people have fixed-line phones in their homes, but many people still have a fixed-line phone bundled with their broadband package. They don’t use it on a regular basis, only to find out after changing the phone that the phone stops ringing. On the day I helped deliver the baby, his home landline was connected to the POTS port of the old optical modem. There was also a phone port on the back of the new cat, but the voice connection was not copied from the old cat, and the phone was completely silent when I picked it up.

The most troublesome voice parameters are the SIP account and password. Ordinary accounts will probably only display half of the password or just an asterisk in the background. Only super accounts can see the full password. If you can see it, take a photo for your record. If you can't see it, take a photo of the name, activation status, and VLAN of the voice connection. After the new cat is registered, fill in the voice link with the connection name of the old cat. Don't guess the SIP password by yourself. If you guess wrong, you may not be able to make calls to the landline, or you may be able to receive calls but not be able to make calls.

IPTV is similar. In some provinces, IPTV and broadband share a VLAN, while in some provinces they are separated. The VLAN and multicast VLAN of the IPTV connection in the old cat background must be copied, otherwise the set-top box will be stuck at 10% or the live broadcast will be black. I replaced the telecom modem for a relative two years ago and the multicast VLAN was missing. The set-top box could be turned on, and the live broadcast kept spinning in circles. The master checked remotely for a long time before he said it was missing by one number.

SN and MAC don’t make your own decisions. Ask first if you can unbundle yourself.

In China Unicom and some mobile areas, when replacing a new optical modem, it is not necessary to fill in the correct LOID to go online. The SN of the old equipment is still tied to the computer room. If the PON light of the new cat is flashing, it is because the SN of the new cat is not registered in the computer room. There are two methods at this time: Either call the operator and ask Zhuangwei to unbind the old SN and connect the new SN to the network, or change the SN of the new cat to the old one. However, not every cat can change the latter, and it also depends on whether the firmware provides access, so don't blindly refresh it yourself.

My habit is to call the operator's customer service before taking action and ask "I want to change all the cats myself. Can the SN of the old cat be unbundled?" If you can solve it, wait for the master to handle it online. If you can't solve it, don't dismantle the old cat first. The SN and MAC of the old cat can be found on the sticker at the bottom and on the background device information page. You can never go wrong taking photos for your records. The operator may push back the parameters you changed through ITMS in the middle of the night. How does this remote control channel work? I'm here What do ITMS and TR-069 mean? I wrote in the article that taking a quick glance before changing cats can avoid detours.

There is still a pitfall in China Unicom's bridging and voice configuration. Don't delete the entire page of old connections. I have seen people delete all the old cat connections and re-create them for the sake of cleanliness. As a result, the landline and IPTV are gone. How to protect TV fixed line after China Unicom changes to bridge mode, the method is written in How to avoid overturning when China Unicom optical modem is changed to bridge connection? Here, it can also be used when changing parameters.

Follow this order before changing, and the new cat will not be scratched when you get it.

I put the parameters I found that night into a sequence. When the old cat can still go backstage, I will go through them. Ten minutes is enough.:

1. Enter the old cat backend and take a screenshot of each of the three device information: LOID, SN, and MAC.
2. Copy down the VLAN ID, 802.1p priority, bridge or routing mode of the broadband connection.
3. Copy the SIP account number of the voice connection if you can. If you can't copy it, write down the connection name and VLAN.
4. Copy the multicast VLAN connected to the IPTV, even if there is no set-top box installed at home.
5. Call the operator and ask if the SN of the old cat can be unbundled. If so, unplug the fiber and replace it with a new cat.

Among these parameters, LOID and VLAN are the two things that are most easily regarded as "only one". In fact, changing the modem is to move your home broadband files from the old device to the new device. If any piece of paper is missing, the computer room will not recognize it. After I was a child, I reported the new Cat SN to the installation and maintenance. After the computer room was unbundled and connected to the network, I used the old Cat to add the VLAN and voice. The connection was completed in less than half an hour. He also took screenshots of a few pages of parameters for the new cat, saying that he would have a solid foundation for future troubles.

I also reminded him one last thing: Before changing the cat, don’t rush to restore the old cat to factory settings. As long as the old cat is still lit, it is a parameter manual that can still be read. ； When you reset it to the factory state, those VLANs and voice accounts that have not been copied will really have to be checked from scratch.