Media Access Control. In IEEE protocols such as Ethernet and Token Ring, the MAC sublayer to the Data Link Layer defines how devices access the medium. This definition includes any congestion- control mechanisms, such as token passing or collisions, as well as Layer 2 addressing. This Layer 2 addressing is often called the MAC Address.
Multicast Address Dynamic Client Allocation Protocol. This protocol was developed to support multicast IP applications. It is defined in RFC 2730. MADCAP allows the dynamic creation and destruction of temporary multicast groups.
Metropolitan Area Network. Usually in an urban area, a MAN is a network that allows communication between buildings that are up to a few kilometers apart. With this density and distance limitation it is possible to take advantage of high- speed network technology such as ATM and SONET.
Multistation Access Unit. In Token Ring networks, a MAU is a device that automatically handles the electrical insertion and removal of individual devices and provides the network pathways for device-to-device communication.
Multicast Border Gateway Protocol. This exterior gateway protocol was built as a set of extensions to BGP to support routing of multicast traffic between Autonomous Systems.
Megabits per second. Equal to 1024 Kilobits per second, or approximately one million bits per second.
See MTBF.
See MAU.
See MII.
A basic network topology in which every device has a point-to-point link to every other device. A special variant of the meshed network is a partial mesh, in which many devices have point-to-point connections to many other devices, but where there isn't a full set of connections.
In a routing table, a number that represents a cost to get to the destination. In the simplest case, the metric simply represents the number of routing hops required to reach the destination. It can also represent a more sophisticated measure of distance based on the cost of sending the packet through each path.
See MAN.
Management Information Base. In SNMP, the MIB is an organized table of data that describes the functioning of the device in detail. The table is organized in a tree structure.
Media Independent Interface. A physical sublayer for Fast Ethernet that provides the ability to have a number of different possible physical media for a Fast Ethernet connection. See also AUI and GMII.
Modulator Demodulator. A modem is a device used to convert digital signals into analog electrical impulses for transmission through analog network equipment such as telephone lines. A second modem at the other end of the line converts these analog signals back to digital form. Modern modems contain many advanced features for noise reduction and data compression, which allows significantly higher effective bandwidth through the link.
Multicast OSPF. MOSPF is a set of extensions to the OSPF protocol that allows it to act as a routing protocol for multicast traffic.
Multi-Protocol Over ATM. MPOA is an updated version of LANE that makes it more effective as a general LAN emulator by allowing it to carry any LAN protocol.
Mean Time Between Failures. In any complex system, it is necessary to treat random individual events, such as device failures, by means of statistical estimates. The MTBF represents how long, on average, a device of a particular type is expected to run continuously before it suffers a failure.
Maximum Transmission Unit. This is the greatest packet size that can be transmitted over a given network link.
A signal that is sent to several, but not all, devices in a particular network region. To work properly, this signal implies that devices must be able to join multicast groups to receive those transmissions that are relevant to them.
There are two general types of fiber optic cable—multimode and single mode. Multimode is capable of supporting light signals of several different wavelengths. It can also operate with an inexpensive low-powered Light Emitting Diode (LED) to inject the signal, since these devices do not have pure single-wavelength light output. The lower costs coupled with lower power requirements means that multimode fiber is perfectly suited to shorter distances such as in a LAN.
See MAU.