network protocols handbook.pdf

195Protocols GuideLocal Area Network and LAN ProtocolsDescriptionLocal Area Network (LAN) is a data communications network connectingterminals, computers and printers within a building or other geographicallylimited areas. These devices may be connected through wired cables orwireless links. Ethernet, Token Ring and Wireless LAN using IEEE 802.11are examples of standard LAN technologies.Ethernet is by far the most commonly used LAN technology. Token Ringtechnology is still used by some companies. FDDI is sometimes used as abackbone LAN interconnecting Ethernet or Token Ring LANs. WLAN usingIEEE 802.11 technologies is rapidly becoming the new leading LAN technologybecause of its mobility and easy to use features.Local Area Networks can be interconnected using Wide Area Network (WAN)or Metropolitan Area Network (MAN) technologies. The common WAN technologiesinclude TCP/IP, ATM, Frame Relay etc. The common MAN technologiesinclude SMDS and 10 Gigabit Ethernet.LANs are traditionally used to connect a group of people who are in thesame local area. However, working groups are becoming more geographicallydistributed in today’s working environment. In these cases, virtual LAN(VLAN) technologies are defined for people in different places to share thesame networking resource.Local Area Network protocols are mostly at the data link layer (layer 2). IEEEis the leading organization defining LAN standards. There are some vendorspecific LAN protocols such as Novell Netware, AppleTalk etc. which arediscussed in seperate sections.Key ProtocolsEthernet Ethernet LAN protocols as defined in IEEE 802.3 suiteFast Ethernet: Ethernet LAN at data rate 100Mbps (IEEE 802.3u)Gigabit Ethernet: Ethernet at data rate 1000Mbps (IEEE 802.3z,802.3ab)10Gigabit Ethernet: Ethernet at data rate 10 Gbps (IEEE 802.3ae)VLAN 802.1Q: Virtual LAN Bridging Switching ProtocolGARP: Generic Attribute Registration Protocol (802.1P)GMRP: GARP Multicast Registration Protocol (802.1P)GVRP: GARP VLAN Registration Protocol (802.1P, 802.1Q)IEEE 802.1P: LAN Layer 2 QoS/CoS ProtocolWLAN Wireless LAN in IEEE 802.11, 802,11a, 802.11b, 802.11gIEEE 802.1X: WLAN Authentication & Key ManagementIEEE 802.15: Bluetooth for Wireless Personal Area Network (WPAN)Token Ring Token Ring: IEEE 802.5 LAN protocolFDDI FDDI: Fiber Distributed Data InterfaceOthers LLC: Logic Link Control (IEEE 802.2)SNAP: SubNetwork Access ProtocolSTP: Spanning Tree Protocol (IEEE 802.1D)