REQUIREMENTS/SPECIFICATIONS
Page 2-5
Maximum Lobe Lengths
The lobe length is the physical length of the cable connecting a station
to its TCU port at the TRXI. Table 2-4 shows the maximum lobe
length, according to ring speed. The cable lengths listed in Table 2-4
are total lengths made up of STP cable only.
Maximum Trunk Lengths
The maximum trunk cable length between the TRXI and another
active device is equal to the maximum drive distance as shown in
Table 2-5. When the neighboring token ring device is a passive device,
the combined length of twice the longest trunk cable plus the longest
lobe cable attached to the passive ring segment cannot exceed the
Maximum Drive Distance.
Maximum Number of Stations
When you use STP lobe cabling everywhere on the ring, the TRXI can
support up to 250 stations at ring speeds of either 4 or 16 Mbps.
Table 2-4. STP Maximum Lobe Lengths
STP Cable Type
Ring Speed
4 Mbps
16 Mbps
IBM Types 1 & 2
300 meters
150 meters
(984 feet)
(492 feet)
IBM Types 6 & 9 (only
for station to wall jack
and patch panels)
30 meters
30 meters
(99 feet)
(99 feet)
Table 2-5. STP Maximum Drive Distance
STP Cable Type
Ring Speed
4 Mbps
16 Mbps
IBM Types 1 & 2
770 meters
346 meters
(2525 feet)
(1138 feet)
IBM Types 6 & 9
513 meters
230 meters
(1683 feet)
(755 feet)
