gawkinet: Stream Communications
1.1 Reliable Byte-streams (Phone Calls)
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When you make a phone call, the following steps occur:
1. You dial a number.
2. The phone system connects to the called party, telling them there
is an incoming call. (Their phone rings.)
3. The other party answers the call, or, in the case of a computer
network, refuses to answer the call.
4. Assuming the other party answers, the connection between you is now
a "duplex" (two-way), "reliable" (no data lost), sequenced (data
comes out in the order sent) data stream.
5. You and your friend may now talk freely, with the phone system
moving the data (your voices) from one end to the other. From your
point of view, you have a direct end-to-end connection with the
person on the other end.
The same steps occur in a duplex reliable computer networking
connection. There is considerably more overhead in setting up the
communications, but once it's done, data moves in both directions,
reliably, in sequence.