provide!logical!communica+on
between%app%processes%running%
on%different%hosts%
• transport%protocols%run%in%end%
systems%%
– send%side:%breaks%app%
messages%into%segments,%
passes%to%%network%layer%
– rcv%side:%reassembles%
segments%into%messages,%
passes%to%app%layer%
• more%than%one%transport%protocol%
available%to%apps%
– Internet:%TCP%and%UDP%