Microsoft Certified Systems Engineer (MCSE) Question:

TCP – Transmission control Protocol is used to establish communication between nodes or networks and exchange data packets. It guarantees delivery of data packets in the order they were sent. Hence it is most commonly used in all applications that require guaranteed delivery of data. It can handle both timeouts (if packets were delayed) and retransmission (if packets were lost). The stream of data is transmitted in segments. The segment header is 32 bit. it is a connectionless communication protocol at the third level (network) of the OSI model.

IP – Internet protocol is used for transmission of data over the internet. IP uses IP addresses to identity each machine uniquely. Message is sent using small packets. The packet contains both the sender and receivers address. IP does not guarantee the delivery in the same order as sent. This is because the packets are sent via different routes. It is a connectionless communication protocol at the third level (network) of the OSI model.

UDP – User Data Protocol is a communication protocol. It is normally used as an alternative for TCP/IP. However there are a number of differences between them. UDP does not divide data into packets. Also, UDP does not send data packets in sequence. Hence, the application program must ensure the sequencing. UDP uses port numbers to distinguish user requests. It also has a checksum capability to verify the data.