Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.

  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

6. Common Lower-Layer Protocols > User Datagram Protocol

User Datagram Protocol

The User Datagram Protocol (UDP) is the other layer 4 protocol commonly used on modern networks. While TCP is designed for reliable data delivery with built-in error checking, UDP aims to provide speedy transmission. For this reason, UDP is a best-effort service, commonly referred to as a connectionless protocol. A connectionless protocol does not formally establish and terminate a connection between hosts, unlike TCP with its handshake and teardown processes.

With a connectionless protocol, which doesn’t provide reliable services, it would seem that UDP traffic would be flaky at best. That would be true, except that the protocols that rely on UDP typically have their own built-in reliability services, or use certain features of ICMP to make the connection somewhat more reliable. For example, the application-layer protocols DNS and DHCP, which are highly dependent on the speed of packet transmission across a network, use UDP as their transport layer protocol, but they handle error checking and retransmission timers themselves.


  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint