Multiplexing - Different protocols can be used to send different messages through the same network. |
Sequencing is the property that data is received by the receiver in the same order as transmitted by the sender, which is not true in a packet-switched network. |
Error control guarantees that error-free data is received by the application programs. Data can either get corrupted by the transmission medium or get lost. Checksums are added to the data and received data is acknowledged. If there is any problem, retransmission occurs. |
Flow control assures that the sender doesnąt overwhelm the receiver by sending data at a faster rate than it can process. |
Error and flow control are handled on an end-to-end basis by TCP and on a hop-by-hop basis by IP. (A hop goes to only one intermediate machine on the network route.) |