What is the difference between an optical modem and a router? One interpreted signal is distributed by one tube, and the route built into the optical modem is sent out

cousin's old house before moving had only one optical modem. The WiFi was provided by it, and the network was set up by it. It worked fine for two years. Last year, during a new home renovation, the whole house had about forty smart devices. The broadband installer asked before leaving, "Do you want to add another router?" She called me and asked, "Isn't the fiber modem capable of sending WiFi? Are these two the same?"

I've answered this question at least ten times. Many people have two machines at home and can't tell who's doing what. This article breaks down the work of these two machines and explains them clearly. After reading, you'll know who is responsible for what your home should manage, and whether you need to spend more money.

to clarify: a translator and a chief butler

the work of a cat is essentially one thing: translator . Optical fiber runs optical signals, but your computer and phone only recognize electrical signals, so there must be a translator in between. Light signal in, electrical signal out—it's that simple. So its scientific name is 'fiber optic modem.' 'Cat' is a transliteration of 'modem,' and it's part of the same family as the 'cat' from the old phone and online internet at home.

router does sorting . There is only one incoming line, dozens of devices at home that need internet access. Whose data is went, how the address number is sent, how is the external network reply sent to the right device? All are handled by the router. Breaking it down reveals four tasks: NAT address translation, DHCP issuing a door number, wireless signal transmission, and firewall gatekeeping.

to give an example: the optical modem is the porter unloading goods from the big truck at the community entrance, while the router is the sorter distributing goods to each household in the community. The movers don't recognize your door, and sorters don't care when trucks arrive—two positions, and if one is missing, a package can't get into your home.

the most important line in this table is the last line. The optical modem's backend has two layers: ordinary accounts can view more statuses but less can be changed. The real super password is in the carrier's hands. I previously wrote about how China Unicom and China Mobile use Ultra Password, China Unicom's article on all four paths I tried one by one. The router's backend password is your own, so you can use it however you like. This difference will be repeated later.

the WiFi on the optical modem is a small complimentary room

So here's the question: since the division of labor is so clear, why can the current optical modem send WiFi and plug in several cables, looking exactly like a router?

because since 2018, most carriers' centralized procurement has been "optical modem router all-in-one machines"—a small router stuffed inside the optical modem. It's easy to understand why operators are willing to do this: the installer can install a machine in ten minutes, so you don't have to adjust the router for you; It also integrates landline ports, IPTV, and remote management into this machine, making it convenient to promote value-added services later.

but this built-in router is a scaled-down version. I once tested a one-month naked optical modem for a month. The article whether it's sufficient without a router is very detailed. The conclusion is: two antennas and about ten units with a device are hard tops. Guest networking, scheduled switches, and parental controls are either not available or deeply hidden. Firmware is managed by the carrier's ITMS, and if you change the configuration yourself, you might be remotely reverted to it in the middle of the night.

so don't be fooled by the name "all-in-one." It's a 'optical modem + a small free router'; the optical modem is the main item, and the router part is a gift. The freebies can be used, but expecting them to support a home with dozens of devices is a bit much.

three-minute judgment: Who's doing the work at your home now

After clarifying the division of labor, the next question is: What kind of wiring method is my home is currently doing? There are only two types on the market, so it's easy to judge.

First: optical modem routing mode (default installation by carrier). the optical modem dials by itself, sends WiFi by itself, and sends door numbers to all family devices. The router either doesn't have one at all, or if it does, it just hangs underneath as a 'signal amplifier' (AP mode). The simplest way to check: check the WiFi name you connect to. Carriers starting with ChinaNet-, CMCC-, ChinaUnicom-, etc., are connected to the optical modem's own WiFi, and the modem is doing its job.

second method: optical modem bridge mode (modified by myself). optical modem was changed to only handle translation, leaving dialing and distribution entirely to the router. How to check: Plug the router's LAN port into the backend, check the WAN port IP on the running status page—if you get an internal network address starting with 192.168 or 10, it means the optical modem is still running a router; if you get a public network address or a carrier network address starting with 100.64, it means the router is dialing on its own and the modem is just acting as an interpreter. should we change the bridge? I've written a separate on this account, and the benefits and costs are clear.

By the way, checking the background is something your phone can do. the Tianyi gateway menu I've clicked through them one by one. Regular accounts can see about 90% of the status.

there is no right or wrong in these two connection methods. With few devices and low requirements, a single optical modem can cover everything without any problem; If you have many devices or want advanced features, you have to have professionals on the job.

four accounts are settled, I'll decide whether to separate them

whether to add a router after the optical modem (or convert it to a bridge). I'm used to doing four accounts.

cover accounts. optical modems are mostly packed into weak current boxes. Once the metal box is covered, the signals emitted by two antennas can be more than half over. The bedroom is separated by two walls from the weak current box and still wants to fill the space—the modem alone can't do it. It's not that it's lazy, it's just that the job description doesn't mention this coverage.

Carrying the aircraft account. ten units are the built-in router threshold for optical modems. Now, at home, I casually count: two or three phones, a TV box, three or four cameras, speakers, a robot vacuum, a door lock, a power outlet— more than ten new devices can't connect to more than once. Carriers have restrictions on the number of devices the optical modem can brought. If the equipment is more than twenty, it must be separated.

Functional Ledger. guest network connects to guests, parents control their children's internet times, port forwarding lets the outside connect to the home NAS—all done in three steps on the router, and on the optical modem, you have to get the super password to enter deep water, and after changing it, you still worry about being pushed back. To save trouble, I left all this work to the router.

stirring up trouble. upgrade router firmware whenever you want, flash whenever you want; The firmware of the optical modem is launched by ITMS late at night, so you basically can't operate it yourself. People who love to tinker will eventually switch to a bridge modem and let it obediently act as the translator, while the rest is done on the router.

the three divisions are exactly three ways to live.

mention the three real configurations I've handled, and you have to take the exact position.

my home: the optical modem was switched to bridge mode for translation only, dialing and FamilyMart distribution were handed over to AX3000T, and dozens of devices were sent back to their own homes. how to connect the router below the optical modem is also important both devices will have conflicts when trying to dial up.

my mom's home: The optical modem stays in router mode, AX3000T hangs down and only sends WiFi. She has five or six devices, enough for video calls, but I don't modify her bridge—if something goes wrong after the modification, she can't handle it at home alone, which would be a loss for her.

cousin's new home: about forty smart devices, with the main router and sub-nodes behind the optical modem, arranged layer by layer. At this scale, relying on the built-in mini router on the optical modem is out of the question.

can see, the number of devices and functional requirements are fixed; the more you tinker, the better. Also, on the optical modem, which port is used for what, which is gigabit and which is hundredm, I've written an article in interface dictionary. Familiarize yourself before wiring to avoid detours.

Finishing: First, identify who is doing the work, then decide whether to do it

compile the above accounts into a single sheet:

and the order is also set: first determine which mode you are currently using, then count the total number of devices at home, then check if there are any blind spots in the coverage, and finally decide whether to buy or modify it. If you reverse the order, you might end up wasting money—if the signal is bad, you first replace the router, only to find out you plugged in the wrong 100M port. I've seen this happen too many times.

in a nutshell: the optical modem manages 'how to get into broadband,' and the router manages 'how to get into the system after entering.' The small roadside you gave is a freebie. Having enough freebies is a blessing; if not, don't force it. Divide the work when it's time to do so.