5
Application Protocols
The Internet, and especially the Web, has become ubiquitous partly because of its ability to represent content in a universal way using a common application protocol – the hypertext transfer protocol (HTTP) [RFC2616]. While HTTP has become by far the most widely used application protocol, supporting web pages and web services, there are a large number of important application protocols used on the Internet. These include e.g. the file transfer protocol (FTP), real-time protocol (RTP), session initiation protocol (SIP), service location protocol (SLP) and the simple network management protocol (SNMP). These and other application protocols are crucial to the scale and breadth of the Internet as we know it today.
Application protocols can be defined as all the messages and methods having to do with inter-process communication via the Internet Protocol, as shown in Figure 1.8. The application layer depends on the transport layer to provide host-to-host communication and port multiplexing allowing multiple processes to communicate between end-points simultaneously.
The Internet of Things makes use of most of the same application protocols used in the Internet for communication between machines and services, for autoconfiguration, and for managing nodes and networks. Application protocols are equally important for the WirelessEmbedded Internet with 6LoWPAN. However, 6LoWPAN is challenging in this respect. The limitations of 6LoWPAN such as small frame sizes, ...
