How Exactly Does A Router Work?

[The Simpleton 2]

I've been wanting to start this thread since a long time but it kept slipping away from my mind. I wanted to know how a router works and how one can connect to the internet using it.I've been using broadband only for 2 years now and before that I was stuck to dial-up. That is my small-town story. But whenever I visit the city I see routers everywhere and everyone seems excited about it. I wanted to know about them but no one/no site has been able to explain in terms that this fool can understand Apart from the working process, I would like to have the following points clarified, if you please... -->Can I ditch my modem and switch to a router, using the same ISP/package?-->Will there be any significant change in speed?-->Any serious cons of using routers?

[kleong 0]

I try to explain as much as I know and anyone please correct me with i am wrong.You cannot ditch you modem. But instead of connecting your modem and pc/laptop, modem should be connected to the router. And from the router, your terminal connects. As for any significant change in speed, there should be any if yours is the only terminal connect to the router. But you should experience a slight dip. However if yours is not the only terminal, then you will experience slowness as all terminals will share the same bandwidth.

[The Simpleton 2]

Hmm that does make sense - so the main advantage of the router is that I can connect to the net from anywhere in the range of the router, right? And yous say speed will get compromised - that sure is a con well anyway I'll continue my research in this are thanks for the reply!

[shadowx 0]

Actually you should be able to keep your current ISP, though it depends... Are you still on Dial up? If so it might not be as simple as a router acts like a modem only it is *always* conncted (unless you fiddle with it anyway...) so if you are on a "pay $XX per month and have unlimited internet" then get a router (check with your ISP first but it shouldnt matter) a router is basically a box, in that box is a switch, a modem and stuff to connect the two together. A switch is like the old telephone switch boards where a person would sit inside a room with loads of connectors (imagine a board in front of you full of leads with two identical ends and lots of holes) when a call came in on line 5 (which has a telephone number of 0123456789) and they were calling someone on line 12 (lets say their number is 9876543210) the person would take that lead, plug one end into hole 5, and the other into hole 12 and the two lines would be connected. Nowadays its computer controlled and is software based so theres no unplugging leads etc...but a switch does the exact same thing. If a pc on port 1 sends a message it sends it like: "To:192.168.1.5 from:192.168.1.2 message:hello, i have some data for you...." obviously its more complex but thats the basics. The router then sees the TO address, and has a table which it looks at called an ARP table (usually) which has entries like:192.168.1.2 Port 2 (ethernet)192.168.1.5: port 3 (ethernet)172.52.212.7 port 1 (Broadband)so it sees that the computer 192.168.1.5 is on the 3rd port/connection so it sends all the data to the wire that is plugged in to port 3 and so the second computer gets its data and everyone is happy. In a router you also have the internet connection (see above) and a complex system of NAT (network address translation) because the websites and the internet only sees the *outside* connection to your router (172.52.212.7 in our example) so it must send all data to that address, but what if PC1 on port 2 wants the data but pc 2 (port 3) doesnt want it. The router performs NAT that basically looks at the data from the internet, sees the name of the PC that asked for it, checks its ARP tables and then sends it on to Port 2 for PC1 and PC2 doesnt know or care! (Im rusty on my NAT so try googling it)And thats it really... A router usually contains a modem (or at least broadband routers do, you probably wont find too many enterprise level routers in PC world or whatever). The idea of a router is it "routes" traffic from one network to another. Imagine it has two sides, one goes to the internet and one goes to your home computers. The router will route all traffic between the two, so if PC1 and PC2 want to talk to each other the router doesnt send that traffic out to the internet, it doesnt need to. It acts as a sort of connector, or forwarder between the two.

[longtimeago 0]

Router is designed for a different purpose and a modem is designed for a different purpose . A modem is meant for converting digital into anolog and anolog into digital signals. It accomplishes modulation and demodulation. Whereas a router is designed for some other purpose, that is routing packets over the WAN and over the internet . A router basically has several configurations like Routing protocals , address configuration ,ACL etc etc. The basic thing which you need to remember is that router has something which is known as the routing table which has information about its neighbouring routers . A router cannot replace a modem or a modem cannot replace a router since they are designed for different purposes. On the other hand modem also does certain tasks of the router like connecting your computer to the external network etc. But in the modem you dont have features like big configurations , console ports etc etc. moreover modem is used for a circuit switching network and router is used for a packet switching network .