Telecommunications and Data Communications Handbook by Ray Horak

Author:Ray Horak
Language: eng
Format: epub, pdf
Published: 2018-07-28T16:00:00+00:00

8.3.6 Gateways

Gateways can perform all of the functions of bridges and routers as well as accomplish protocol conversion at all seven layers of the OSI Reference Model. Generally consisting of software residing in a host computer equivalent in processing power to a midrange or mainframe, gateway technology is expensive but highly functional.

Protocol conversion, rather than encapsulation, can serve to fully convert from Ethernet to Token Ring to FDDI or any other standard or proprietary protocol. Additionally, protocol conversion can address higher layers of the OSI model, perhaps through Layer 7, the Application Layer. As the process of protocol conversion is complex, gateways tend to operate rather slowly as compared to bridges and routers. As a result, they impose additional latency on packet traffic and may create bottlenecks of congestion during periods of peak usage. In a large and complex enterprise network, routers tend to be positioned at the edges of the network where they can be used to full advantage. Therefore, they make complex and time-consuming decisions and invoke complex and time-consuming processes only where required. Switches tend to be positioned within the core of the network because they can operate with greater speed, perhaps based on the instructions of the routers.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.