Computer Network Gateways
By Stephen Bucaro
When networks with different protocols, such as Ethernet and Token Ring need to be connected
together, this requires reconstruction of the data packets. To do this, information from above
the network layer is required. A gateway is a device that can function at all seven layers of
the OSI model. A gateway can connect a LAN to a WAN, a LAN to a mainframe, translate protocols,
or convert transmission media.
A router that connects a local subnet to other networks is called a "default gateway".
A gateway that connects a LAN to the Internet is called a "proxy server" when it receives all
requests for Internet access from the LAN and routes them to the Internet. A gateway that
connects a LAN to the Internet is called a "firewall" when it provides security and protection
against external intrusions.
More Networking Protocols and Standards:
• Integration of IPv6 with IPv4
• Basic TCP/IP Networking
• IPv4 Datagram Fields
• Video - Data Link Layer of OSI Networking Model
• Network Switches
• Video - Introducing the OSI Model
• Network Routing Protocols - IGRP, EIGRP, OSPF, ISIS, BGP
• IPv6 Prefix Length Notation
• IPv6 Multicast Addresses
• Wireless Standards - 802.11a 802.11b 802.11g 802.11n 802.11i Explained