Why doesn't Unicom optical modem switch to bridge fail? Don't delete the original and add a new one; the TV landline will be fully protected

Last week, my colleague Xiao Jiang excitedly came to me, saying he had followed the route of China Unicom Super Password to get the dynamic password. Going backend, he saw four or five records lying in the WAN connection list, so he thought about changing the bridge, leaving only a clean one—deleting all the annoying ones and building a new bridge. That night, the TV at home went black, the old man's landline had no dial tone, but the router was dialed, and he was the only one in the family who could get online.

I went to his house and was amused: this wasn't a damaged bridge modification, it was driving out other tenants with them. After cleaning up the mess, I realized that Unicom's machine actually has a more stable modification: add a bridge, but the original one didn't even move a finger. This article will clearly explain the half-bridge setup from start to finish.

first understand the WAN connection table: it's not a configuration item, it's a business list

many people get overwhelmed when they see the 'WAN connection' list after entering the super admin backend, but each entry is actually a standalone position, not redundant junk. A typical Huawei custom phone from Unicom looks like this:

the VID_xx at the end is the VLAN, which is different for each province and region. That's why all tutorials tell you to "copy the VLAN before you get started." Xiao Jiang's mishap happened here: he thought there should only be one person online on the list, so he cleared both OTHER and VOICE. The TV and landline suddenly ran out of supplies, which had nothing to do with the internet connection. If you want to know your home VLAN, where to check, the old article on VLAN checking from Hunan Unicom, the method is common across provinces.

half-bridge approach: add a strip, but don't change the original strip

usually, when changing bridges, you directly change the original INTERNET_R to Bridge mode or delete and rebuild it. The problem with this route is that after the optical modem completely retires from routing mode, all the services it depends on had to be rearranged—IPTV either uses single-wire multiplexing for VLAN, or uses router IPTV functions, and fixed-line calls can only rely on the VOICE to survive. previously wrote about whether revising bridges is worth it, most of the four things listed in the about cleanup came from this way.

Half Bridge thinks the other way: the original stream stays unchanged, IPTV continues to use OTHER, landline continues with VOICE, and the optical modem's WiFi and network port continue to send addresses as usual. I just create a new WAN connection , select Bridge mode, and bind a free network port specifically to feed the router. In other words, the optical modem has two doors opened: one is the old main door for old services, and the other is a new small door that leads directly to the carrier, and the router can dial through the small door.

this approach works best on Huawei machines because in its new WAN interface, you can check "Port Binding," allowing you to assign specific ports to the new bar. Xiao Jiang's phone is a Huawei Unicom custom phone for 2024, which is just right for this setup.

just take five steps and just follow the dots

first step is to resolve the super password issue. The new Unicom firmware password is dynamically issued, so static default is basically impossible. The specific four paths in the 1288 article, so I won't repeat it here. Before entering the backend, I casually downloaded a configuration file and picked any of the three tricks from the Conf backup post on the optical modem the Conf backup. Even if you mess up the changes, you can still save them.

go to the backend, find the "WAN Connection" or "Network - Broadband Settings" page, and follow this order:

Step (5) is the easiest to miss in the entire process. The original internet strip usually had port binding from LAN1 to LAN4 plus WiFi, all hooked. If you don't remove LAN2 from it, LAN2 will be registered under two WANs at the same time, which can cause inability to dial at best, or at worst, have to be checked intermittently for ages. Some firmware requires rebooting the optical modem after removing it for it to take effect. If you're unsure, just restart once, which takes two or three minutes.

After

done, plug the router's WAN port cable into the optical modem (LAN 2), enter the router's backend and set the internet access mode to broadband dial-up. Copy the account password according to the installation work sheet—Unicom accounts usually have a string of letters suffix, not missing a single character. dial-up settings details written before. No need to tinker with MTU; the default is 1492.

verification, focus on four things; if you're missing any one, don't quit

After dialing the number

the router, don't rush to get excited—go through all four items one by one. First, check the IP you got from the router's WAN port—it's not starting with 100 or 192.168, so you really have left the community; Second, turn on the TV, and you can access live channels, but the list won't go black—you're still using the original OTHER; Third, pick up the landline and listen to the dial tone—if there's a buzzing sound, the VOICE is alive. the landline business line you have no idea what you've touched; 4. Plug the optical modem into the LAN1 on your computer, and you can still access the 192.168.1.1 backend—this is where semi-bridge is more comfortable than full-bridge. After full bridge, the optical modem stops sending addresses, so you have to manually set up an IP to access the backend. that rescue post about the backend losing contact after bridge people still searched for it, so you can see how many people have fallen for it.

Xiao Jiang's family has completed these four things: they get a public IP address, the TV remains normal, the old man's landline remains as usual, and he can turn off or keep the fiber modem or WiFi whenever he wants. There's no issue of who depends on whom.

being pushed back in the middle of the night is the real backup plan

only one thing half-bridge can't prevent: Unicom's remote management platform. The bridge you privately built is considered unplanned by the bureau. If the platform releases a standard configuration in the middle of the night, it might be wiped out. The feedback is easy to recognize—the router's PPPoE suddenly disconnects, and even redialing won't report it. When I checked the backend, the newly created IP was gone, so it was probably pushed. The ITMS on the telecom side recounted that I wrote a complete article three countermeasures and scripts were all in 851. Unicom had a logic: either accept and reconfigure everything, either turn off the cycle reporting and take a gamble, or call 10010 to report a "user-provided router" work order to ask the data center not to touch your data.

mobile machines want the same gameplay, the approach is the same but the details differ. Just follow the VLANing and RMS sections in the about mobile switching to bridge. If your firmware has a new button that turns gray, and some ZTE and FiberHome machines only allow modification but not build, then revert to the usual approach: just change the original file to mode, don't delete it. If the IPTV really breaks, press bridge and then restore the IPTV recovery restore the OTHER port.

who is worth using a semi-bridge

ultimately, this is for those who want it all: public IPs, IPTV watches, landlines to use—none of them want to be delayed. Half bridging is the solution with the least changes. If the family hadn't installed IPTV at all and the landline had been dismantled long ago, the whole bridge would have been finished, so don't add drama to yourself. Another scenario is 754 the single-cable multiplexing method: after the optical modem fully bridges, you can use the switch to connect the VLAN to recover the IPTV. If you already have pre-installed cables at home, you can do this easily; if not, it's easier to use a half-bridge setup.

the order to wrap up: backup of the configuration, copying VLAN, creating a new bridge and binding to LAN2, removing the original LAN 2, dialing the router, and four verification steps—twenty minutes to complete. After the first week after the change, I checked the router's dial-up status. If it doesn't get pushed back, the issue is basically settled.