In http ( over tcp) there is a header which called keep "alive"

I dont understand how a connection can be open in tcp if all packets come from different

source ( router decision - over the internet)

link|improve this question
feedback

closed as not a real question by ErikA, John Gardeniers, Ward, Shane Madden, MDMarra Nov 15 '11 at 19:43

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. See the FAQ for guidance on how to improve it.

1 Answer

up vote 5 down vote accepted

TCP keepalives are an optional implementation and as such, are not generally implemented. An HTTP keepalive is not the same thing as a TCP keepalive.

A TCP session can be maintained even when data between the source and destination takes different paths because TCP doesn't care what path the data takes (asymmetric routing). TCP maintains session state via a 4 tuple: sourceaddress:port<->destinationaddress:port.

It doesn't matter what path the data takes between the 2 hosts.

link|improve this answer
feedback

Not the answer you're looking for? Browse other questions tagged or ask your own question.