23
16-PORT TYPE 3 MAU
3.1.3 A
DJUSTED
R
ING
L
ENGTH
In networks that use more than one MAU, adjusted ring length (ARL) is the
total length of the cable connecting MAUs (the main ring) minus the shortest
inter-MAU cable. Patch cables less than three feet in length are not included
in this calculation. See the diagram below.
MAU
100 feet
150 feet
50 feet
MAU
MAU
(Subtract length of
shortest section
Attaching
Device
Attaching
Device
150 + 100 = 300 ft. (total main ring length)
300 - 50 = 250 ft. (adjusted ring lenght)
Figure 3-5. Adjusted ring length.
The use of ARL is intended to simplify network planning. The length of the
longest lobe in the network is added to ARL, and the sum is compared to a
chart later in this chapter to determine maximum ring size. See
Section 3.2,
Calculating Distances
.
3.1.4 L
OBE
L
ENGTH
The distance between each attaching device and its MAU is very important in
network planning. Maximum lobe lengths are a function of several factors,
and they will vary depending on how the network is configured. See
Section
3.2, Calculating Distances
.