Network Router Speed?

Question

Greetings. I've recently started network engineering and I've got a question about network speeds. From this video:
https://youtu.be/n2D1o-aM-2s?t=1274
The person explains that if you send a file and it goes though multiple ISP's its speed will be limited to the receiving router on the other end ( if that's how i understand it ). Could anyone explain how that works with the speeds or do they change depending on ISP's?

Answer 1

You understand " its speed will be limited to the receiving router on the other end" however, you forget that you aren't just talking to the router at the other end!!! That router has to be connected to a server/computer and that computer/server has to connect to the router which then ROUTES back to you. The server at the other end may be the limiting factor, they can be overloaded by users. The Router might be the block if it can't handle the traffic, or the line from the ISP to the router could be the limiting factor if it isn't large enough to handle the traffic.

Limits are placed on all of those items and the slowest item will be the limiting factor.. it could even be on YOUR end if the ISP you have isn't delivering enough bandwidth to meet your users demands. Networks are end to end connections, everything is in the path.

If you want to SEE that in action run a "trace route" from your computer to the system you want to send a packet/file into. You may find other routers in the middle are the issue with speed.

Answer 2

It will depend on how busy the Internet is at any point along the route, and the bandwidth of the sending and receiving servers connection. For standard broadband the upstream bandwidth is a lot lower than the downstream. It will also depend on how many people happen to be communicating with that server.

Answer 3

More accurately, the entire chain is only as strong as its weakest link. You can only download as quickly as the slowest connection in the relay permits. If you're using 100mb/s connection, but the server to which you are connected is using an old 2400 baud modem, the fastest you could possibly receive from that server is 2.4kb/s.