When you reset the wi-fi router, why does it take so long to turn on? What happens during that time?
In: Technology
Your router has several hardware components.
* Integrated switch (physical network connections)
* Wireless RF circuitry for sending and receiving data
* Processor and routing software to handle data-link stuff
* NVRAM – non-volatile memory – stores configuration information and system software
* RAM – stores currently running configuration and copy of system software
The router will run a self-test on its hardware when starting up. During this period, it will give out fault codes and other diagnostic information if the system has internal data corruption or other hardware errors. This takes up time. Fun fact – you can actually connect a serial line directly to the board on most routers and observe this in a console.
So the memory copy rates aren’t all that fast when a router boots up either. This is why, for instance, it still takes a good minute or two to update the firmware after you have downloaded it. After boot, It will copy your firmware / operating system and configuration from NVRAM to RAM. This takes up a good deal of time.
Once the hardware tests are passed and the router’s software is loaded up, each piece of hardware gets “initialized”. This is the part where the router looks at your connected devices and establishes connections. Things that are wired into the switch (such as a modem or gateway), checking the current bands and selecting the least congested one, and bringing any other software on the router up (such as a VPN service).
There is a lot more going on under the hood than listed here, but this is ELI5 after all.
EDITS: Just fixed a couple typos. I also see lots of people making a valid point that this isn’t “ELI5”. Also that a router is “just a small computer”. The thing is, it isn’t just like a small desktop/laptop. It has very specific hardware and software that accomplishes a very specific set of tasks. Unfortunately, this question can’t really be meaningfully answered in the framework of ELI5. A 5 year old would just have to accept that it needs time to start everything up and get everything talking to each other.
The router itself is basically a mini computer. Just like the computer you use, it has a CPU, memory, storage, an operating system (the “firmware”), etc. All of these are of course specialized for its job of handling network traffic.
And just like your computer, it needs time to start up after it’s been turned off. During that time it does the same sorts of things your computer does when it boots – initializing its hardware, loading the operating system, and launching various software components that allow it to do its job.
The hardware on routers is usually quite weak, since they only need to be good enough to perform the one job they are designed for. They run much slower than your computer. So, even though a router is a comparatively simpler device, it may take longer to start up than your computer.
Routers are mini-computers that also can send and receive wifi.
The router has to turn on and boot up, just like any other computer.
Latest Answers