10
LINK SEGMENT
— The link segment of coaxial cable is a segment which has no
MAU devices but links two LAN devices such as repeaters together in a point-to-
point configuration. By the inherent nature of 10BASE-T and fiber optic media,
these media are point-to-point link segments.
MEDIA ATTACHMENT UNIT (MAU)
— Provides an electrical attachment to
a 10BASE2 or 10BASE5 coaxial cable segment. The MAU will convert the IEEE
802.3 composite signal into separate signals for Data In (circuit A and B), Data Out
(circuit A and B), Control In (circuit A and B). Control Out (circuit A and B),
Voltage Plus and Voltage Common.
N SERIES
— A barrel shaped, threaded connector used on 10BASE5 (thick
Ethernet) coaxial cable.
PROPAGATION DELAY
— The time it takes a signal to travel from the input of
a system component to the output. Usually measured in nanoseconds. IEEE 802.3
has specific propagation delay maximums for computing propagation budgets
when designing a LAN. Cable length plays a major role in propagation delay. (i.e.,
a 50 meter [164 ft.] AUI cable has a maximum allowable propagation delay of 257
ns.) The propagation delay of cable is dependent on length and velocity factor of the
cable type. There are also propagation delays associated with electronics attached
to the system.
SIGNAL QUALITY ERROR (SQE)
— Also referred to as Collision or Collision
Presence. This occurs when two devices attempt to transmit at the same time
which is an illegal condition.
SQE TEST
— Commonly referred to as heartbeat, is a special 802.3 signal sent by
the MAU to the DTE to test the collision reporting mechanism. Some DTE want
SQE Test and others do not. Repeaters do not want SQE Test.
THICK ETHERNET
— see also 10BASE5
THIN ETHERNET
— see also 10BASE2
MR125DBook Page 10 Wednesday, August 21, 1996 4:24 PM
