Introduction to Data Communications
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For example, in the following Token Ring, there is a mixture of cable types. The first step is to convert the cable lengths to their equivalent Type 1 cable length.




Cable	Type		Length	Conversion Factor	Type 1 equivalent length

A	Cat 5 UTP	80 ft		1.7		136.0 ft

B	Type 6 STP	12 ft		1.3		15.6 ft

C	Cat 5 UTP	65 ft		1.7		110.5 ft

D	Cat 3 UTP	127 ft		3.0		381.0 ft

E	Type 2 STP	185 ft		1.0		185.0 ft



			Total Cable Length =		828.1 ft

Ring Length = Total Cable Length + (number of MSAUs x 25 ft)

Ring Length = 828.1 ft + (4 x 25 ft) = 928.1 ft

If you check the maximum ring length parameters, you will see that this ring would function within the specifications for a 4 Mbps but not for a 16 Mbps Token Ring.

Introduction to Data Communications
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