Dennis Lee Bieber wrote:
The network protocols form a layered stack. The bottom of the stack is the physical connection: coax (now rare), twisted-pair (cat-5/cat-6 cable with rectangular plugs on the end), fiber optic... etc. At some level above that is the part that translates data packets (containing IP or IPX or other addressing scheme) to a data packet with the MAC/hardware address of the destination connection -- both IP and IPX could be running over the same cable without conflicts. Above that is the part that handles, say, TCP or UDP -- this is the part that detects TCP missed packets from a connection. Somewhere above that layer is where things like FTP, SMTP, POP3, Telnet, HTTP, etc. live.
Geez, this network programming stuff is complicated, yet at the same time very interesting and, well, not all *that* complicated! I guess it helps to keep reading this stuff over and over, too. I just read the section on socket programming in Programming Python, which also discussed these layers and such.
I don't know why, but I find it all very interesting! I think one reason is because this is sort of a "coming together" of everything I've ever known/heard/read about the internet, but I never stopped to put it all together until now.
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