Enterasys brim-f6 Benutzerhandbuch

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Token Ring
2-7
Review of Networking
Token Ring networks can use a variety of physical cabling, including Unshielded 
Twisted Pair (UTP), Shielded Twisted Pair (STP), or fiber optic cabling. The 
characteristics of the various cables can directly impact the operational limitations 
of a Token Ring network which uses a particular media. 
Lobe Cable Lengths for 4 Mbps Token Rings: The operation of a 4 Mbps Token 
Ring network imposes some relatively generous limitations on the maximum 
length of any station cable (also called a lobe cable) connected to an active port 
in the network as shown in the following list:
-
IBM Types 1, 2 STP: 300 m
-
IBM Types 6, 9 STP: 200 m
-
Category 5 UTP: 250 m
-
Categories 3, 4 UTP: 200 m
-
Multimode Fiber Optics: 2000 m
-
Single Mode Fiber Optics: 2000 m
Lobe Cable Lengths for 16 Mbps Token Rings: 16 Mbps Token Ring networks 
also impose limitations on the maximum length of any media connected to an 
active port as shown in the following list:
-
IBM Types 1, 2 STP: 150 m
-
IBM Types 6, 9 STP: 100 m
-
Category 5 UTP: 120 m
-
Categories 3, 4 UTP: 100 m
-
Multimode Fiber Optics: 2000 m
-
Single Mode Fiber Optics: 2000 m
RI/RO Cable Lengths for 4 Mbps Token Rings: 4 Mbps Token Ring networks 
also require that Ring-In/Ring-Out (RI/RO) connections be no longer than a 
certain amount. This amount is dependent upon the media being used for the 
RI/RO connection as shown in the following list:
-
IBM Types 1, 2 STP: 770 m
-
Category 5 UTP: 250 m
-
Categories 3, 4 UTP: 200 m
-
Multimode Fiber Optics: 2000 m
-
Single Mode Fiber Optics: 2000 m
RI/RO Cable Lengths for 16 Mbps Token Rings: 16 Mbps Token Ring networks 
also require that Ring-In/Ring-Out (RI/RO) connections not exceed the 
lengths given below:
-
IBM Types 1, 2 STP: 346 m
-
Category 5 UTP: 120 m
-
Categories 3, 4 UTP: 100 m
-
Multimode Fiber Optics: 2000 m
-
Single Mode Fiber Optics: 2000 m