The Datagram Congestion Control Protocol (DCCP) is a new transport layer protocol.It provides bidirectional unicast connection for congestion-controlled unreliable datagram s. It is unreliable protocol similar to UDP, but provides congestion control mechanism like TCP so it s an alternative protocol for application that requires low delays and where a small data degree of data loss is acceptable. DCCP can easily extend to support the different CCID. The main objective of this book is to implement Datagram Congestion Control protocol(DCCP) stack optimized for portability so it can be run on Linux as well as on Windows platform. DCCP Implements the main DCCP specifications plus CCID 2 and DCCP-Nat encapsulation for IPv4.Furthermore this stack can also be used to work with VOIP client