Gateway is a term for a broad category of network components that operate at the higher level of the OSI model. Read more for examples and complete definition.

What is Gateway?

A term for a broad category of network components that allow communication between different networking architectures and different protocols. Gateways generally operate at the higher levels of the Open Systems Interconnection (OSI) reference model for networking. They are commonly used to provide connectivity between two different protocol stacks that might be running on different systems.

Examples include the following:

  • E-mail gateways - for example, a gateway that receives Simple Mail Transfer Protocol (SMTP) e-mail, translates it into a standard X.400 format, and forwards it to its destination
  • Gateway Service for NetWare (GSNW), which enables a machine running Microsoft Windows NT Server or Windows 2000 Server to be a gateway for Windows clients so that they can access file and print resources on a NetWare server
  • Gateways between a Systems Network Architecture (SNA) host and computers on a TCP/IP network, such as the one provided by Microsoft SNA Server
  • A packet assembler/disassembler (PAD) that provides connectivity between a local area network (LAN) and an X.25 packet-switching network

A gateway is usually a dedicated device or a set of services running on a dedicated computer. Gateways are essentially devices that direct network traffic in some fashion and translate that information.