Gateway

A gateway  is an internetwork  device which  joins different  network  protocols  together. It woods on all  seven  layers of OSI model. Gateways are also known as  protocols converters. Gateway can  accept a packet formatted for one protocols and convert the  formatted  packet into another  protocols. Similarly a gateway can forward packets  across different  networks  that may  also use  different  protocols frequency. If network  a is a token  ring network  using  TCP/ IP and network  B is  a newel Netware network a gateway can relay frames between the two. This  means that a gateway has  the ability  of translating  between  frame  formats  but also  different  protocols.

                                                                        Figure gateway operations all  layers of OSI model

Task of gateway is very  different  as it  shall  take  care of  different  frame sizes  data  rates formats  acknowledgment  schemes, priority  schemes etc. A network  gateway can be  implemented in software  hardware  or as combination of both. Now  we will  discuss about  router in detail .