1. User Datagram Protocol (UDP) IP headers cannot identify application programs running a computer UDP is an end-to-end or transport protocol that allows an application program to serve as the end-point of communication

2. UDP Characteristics End-to-end Connectionless Message-oriented – Each UDP message must fit within one IP datagram Best-effort – UDP message can be lost, duplicated, or corrupted – Suitable for applications that can tolerate delivery errors Arbitrary interaction – One-to-one, one-to-many (IP multicast/broadcast), many- to-one Operating system independent – Relies on UDP port numbers to identify application

3. UDP Port Number

4. UDP Encapsulation