Cabletron Systems STHI manual Unshielded Twisted Pair UTP, UTP Cable Categories

APPENDIX B

Media Specifications

Use of the STHI may involve a variety of cable types. The STHI hub’s network ports support either Shielded Twisted Pair (STP) or Unshielded Twisted Pair (UTP) cabling, depending on the STHI model, while Token Ring Port Interface Modules (TPIMs) allow for network expansions onto UTP, STP, Multimode Fiber Optic, and Single Mode Fiber Optic cabling.

The HubSTACK Interconnect cable (Part Number 9380141) which is needed to interconnect an STH hub with an STHI is provided with each STH.

Take care in planning and preparing the cabling and connections for the network. The quality of the connections and the length of cables are critical factors in determining the reliability of the network.

B.1 Unshielded Twisted Pair (UTP)

STHI models 22 and 24 and TPIM-T2 support D-inside wiring (DIW) voice grade Unshielded Twisted Pair (UTP) cable as described below and in EIA SP-1907B. All category 5, all category 4, and some (see Section 2.3.2 on page 5) category 3 UTP cables meet Token Ring network performance requirements.

B.1.1 UTP Cable Categories

Both UTP modules (STHI-22 / 24) support UTP cables classified as category 3, 4, and 5.

UTP cable is categorized according to the following specifications:

Category 3 consists of (usually) four Unshielded Twisted Pairs of 24 AWG solid wire for data or voice communication. (IBM Type 3 is coincidentally the same as UTP Category 3.) It is typically used to wire cable runs within the walls of buildings. In some installations, pre-existing UTP building wiring can be used for Token Ring cabling.

At 16 Mbps ring speeds, some Category 3 cable does not meet WARNING the performance requirements of a Token Ring network.

This may impose lower limits on lobe cable distances and ring node counts. See Table B-1.

Page B-1