Token Ring Physical Connections - Cisco 7000 Hardware Installation And Maintenance

Preparing Network Connections
Figure 2-19

Token Ring Physical Connections

The term Token Ring refers to both IBM's Token Ring Network, which IBM developed in the 1970s,
and to IEEE 802.5 networks. The IEEE 802.5 specification was modeled after, and still closely
shadows, IBM's network. The two types are compatible, although the specifications differ slightly.
The IBM Token Ring specifies a star topology, with all end stations connected through a device
called a multistation access unit (MSAU). IEEE 802.5 does not specify any topology, although most
implementations are based on a star configuration with end stations attached to a device called a
media access unit (MAU). Also, IBM Token Ring specifies twisted pair cabling, whereas IEEE
802.5 does not specify media type. Most Token Ring networks use shielded twisted pair cabling;
however, some networks that operate at 4 Mbps use unshielded twisted pair cable. Table 2-13 shows
a comparison of the two types.
Table 2-13
Network Type Data Rates
IBM Token Ring 4, 16 Mbps
network
IEEE 802.5 4, 16 Mbps
network
In the typical Token Ring network shown in Figure 2-20, lobe cables connect each Token Ring
station (TRIP port) to the MSAU (or MAU), and patch cables connect adjacent MSAUs (or MAUs)
to form one large ring.
2-94 Cisco 7000 Hardware Installation and Maintenance
Token Ring Network Interface Connectors, DB-9 and MAU Types
IBM Token Ring and IEEE 802.5 Comparison
Stations/ Segment
260 shielded twisted pair Star
72 unshielded twisted pair
250
TRIP end
MSAU or
MAU end
Topology Media
Twisted pair
Not specified Not specified Baseband
Access
Signaling Method Encoding
Baseband Token Differential
passing Manchester
Token Differential
passing Manchester