I saw a map of undersea internet cables the other day and it’s crazy how many branches there are. It got me wondering - if I’m (based in the UK) playing an online game from someone in Japan for example, how is the route worked out? Does my ISP know that to get to place X, the data has to be routed via cable 1, cable 2 etc. but to get to place Z it needs to go via cable 3, 4?
IPs and packets are well and good and I do have a decent working knowledge of TCP/IP, but what physically is actually happening? Thanks for replying anyway!
Physically, at the physical / link layers, an Ethernet transceiver integrated circuit is used that knows how to take data provided by the cpu and communicate it by sending signals along the RJ45 Ethernet physical layer to communicate with the switch. By looking at the datasheet and IEEE 802 specs one could figure out more detail.