each segment so that the destination's TCP protocol can put the segments
back into the order the application intended. After these segments are
sent, TCP (on the transmitting host) waits for an acknowledgment of the
receiving end's TCP virtual circuit session, retransmitting those that aren't
acknowledged.
connection. What is created is known as a
sent before the recipient's TCP sends back an acknowledgment. With every-
thing agreed upon in advance, the path is paved for reliable communication
to take place.
checking, is no small task. TCP is very complicated and, not surprisingly,
costly in terms of network overhead. And since today's networks are
much more reliable than those of yore, this added reliability is often
unnecessary.
port layers, I'll demonstrate how TCP segments a data stream and prepares
it for the Internet layer. The Internet layer then routes the segments as pack-
ets through an internetwork. The packets are handed to the receiving host's
Host-to-Host layer protocol, which rebuilds the data stream to hand to the
upper-layer applications or protocols.