What does the Transport Layer do?
Provides the actual communication facilities for most distributed systems
TCP (Transmission Control Protocol)
UDP (User Datagram Protocol)
What is the difference between TCP and UDP?
TCP (Transmission Control Protocol):
Connection-oriented, reliable, stream-oriented communication
UDP (User Datagram Protocol):
Unreliable (best- effort) datagram communication
What to do if different applications need common functionalities, e.g., for fault tolerance, security, or synchronization?
A rich set of communication protocols
(Un)marshaling of data, necessary for integrated systems
What is the diffrence between transient and persistent communication?
Communicating server discards message if it cannot be delivered at the next server, or at the receiver
Message is stored at communicating server as long as it takes to deliver it
What is the difference between synchronous and asynchronous communication?
Sender is blocked until its request is known to be accepted or completely processed
No such functionality