Unshielded Twisted Pair (Utp); Physical (Phy) Protocol; Media Access Control (Mac) Protocol - 3Com 3C780 - LinkBuilder FDDI Base Unit User Manual

Unshielded Twisted Pair (UTP)

The ANSI TP-PMD standard provides these services for UTP:
Cable requirements for category 5 UTP as defined by EIA/TIA-568
Electrical requirements for UTP transceivers
FDDI-UTP cable connector

Physical (PHY) Protocol

The Physical protocol is responsible for encoding and decoding of data and
control information on the FDDI network. It specifies the following:
4B/5B nonreturn to zero inverted (NRZI) encoding scheme (for fiber and
STP modules)
MLT-3 with stream cipher encoding scheme (for UTP modules)
Clocking rules
Clocking frequency of 125 MHz
Serial-to-parallel conversion rules

Media Access Control (MAC) Protocol

The Media Access Control protocol controls the flow of data on the FDDI ring.
The MAC typically exists in every hub and station accessed by the FDDI ring,
but stations without MACs are allowed. This protocol specifies the following:
Token-passing protocol
Capture and retransmission of token
Packet formation and framing of data
Address generation and recognition
32-bit cyclic redundancy check (CRC) verification and error detection
Recovery mechanisms
Overview
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