Cisco Systems manual Token Ring Connection Equipment, VIP-4R/4T Installation and Configuration

VIP Port Adapter Functions

Figure 15 Token Ring Network Physical Connections

			MAU or MSAU						MAU or MSAU
Ring					Ring	Ring				Ring
	in 1	2 3 4 5 6		7 8 out			in 1	2 3 4 5 6 7 8 out

Stations Stations

MAU or MSAU			Patch		MAU or MSAU
			cables
Ring		Ring		Ring	Ring
in 1 2 3 4 5 6	7	8 out		in 1	2 3 4 5 6 7 8 out

	Lobe
	cables	H2058
Stations	Stations

Token Ring Connection Equipment

You will need an 802.5 MAU or an MSAU to provide the interface between the 4R port adapter Token Ring interfaces and the external ring, and a Token Ring lobe cable between each 4R port adapter interface and the MAU or MSAU. Lobe cables connect each Token Ring station (4R port adapter interface) to the MAU or MSAU, and patch cables can connect adjacent MSAUs to form one large ring.

4R port adapter interfaces operate at either 4 or 16 Mbps. The default speed for all 4R port adapter interfaces is 4 Mbps, which you can change to 16 Mbps on any port using the ring-speedn configuration command, where n is the speed (4 or 16) in Mbps. The speed of each Token Ring port must match the speed of the ring to which it is connected. Before you enable the Token Ring interfaces, ensure that each is set for the correct speed, or it can bring down the ring.

Caution Each 4R port adapter interface must be configured for the same ring speed as the ring to which it is connected, either 4 or 16 Mbps. If the port is set for a different speed, it will cause the ring to beacon, which effectively brings the ring down and makes it inoperable.

32VIP-4R/4T Installation and Configuration