CALCULATING RING LENGTH
Page C-3
6.
Determine your Actual Longest Lobe length, combine:
TCU port to patch panel
feet
Wiring closet to wall plate +
feet
Wall plate to station
+
feet
Longest Lobe Length
7.
Compare the Maximum UTP Lobe Length, calculated in step
5, with your networks longest lobe, from Step 6. If your Actual
Longest Lobe exceeds the Maximum UTP Lobe Length
(negative result in step 7), you must adjust your lobe length or
add active components (repeaters) to extend the available trunk
cable length.
I
f you need further assistance with your network design, contact
Cabletron Systems Technical Support.
Use Figure C-1 to follow the calculations using the UTP Cable Length
Worksheet for Single Wiring Closets in this example for a 4 Mbit/sec
ring:
Single Wiring Closet
4 Mbit/sec
1. Maximum Drive Limit
1. 1263 ft.
2. Internal Trunk Length
(7 concentrators in 2 racks = 150')
2. – 150 ft.
3. Type 1 Cable Budget
3. 1113 ft.
4. Type 1 STP to UTP Conversion
4. X .39
5. Maximum UTP Lobe Length
5. 434 ft.
6. Actual Longest Lobe (Station 2)
(8' x 3/2) + 185' + (30 x 3/2) = 242'
6. – 242 ft.
7. Result
7. 192 ft.
The result is positive and no repeaters or cable adjustments are
needed.