GarrettCom 500-Series manual Example 3 Magnum, Internet

Magnum 500-Series Switching Hubs Installation and User Guide (08/98)

Example 3 : Magnum 528

In another situation similar to Example 2 above, the network may need to be linked to a Fast Ethernet backbone. This application is handled by the Magnum 528 using one 100Mb switched port for local high speed servers and users, while using the other 100Mb switched port for a link upstream.

Using two Magnum 528s and linking a 100Mb switched port from each unit, one can implement a Fast Ethernet switched connection which can run in full duplex mode. The result is similar to “stacking” the two Magnum 528s to provide a net total 16 ports of switched 10Mb plus 2 ports of switched 100Mb.

When using a Magnum 528’s 100Mb switched port as a link, it is frequently desirable to make the connection to the upstream device using fiber cable operating at 100Mb speed. In this situation, an external 100Mb Media Converter unit (such as a Magnum 15E) is used to change from twisted pair cable to fiber cable.

Because commercially-available 100Mb Media Converters do not support 10/100 speed auto-negotiation, it is necessary in this situation to operate both ends of the fiber link with ports that have fixed 100Mb-speed capability. In addition, since 100Mb fiber cable has severe distance limitations at half-duplex, it is almost always necessary to operate such a fiber link in the full-duplex mode. Many low-end switching hubs that only have auto-negotiation on their 100Mb ports cannot support this application, but the Magnum 528 . . . with fixed 100Mb speed as a default setting, and with manually- selected half- or full-duplex mode per Fast Ethernet port . . . handles this readily.

100Mb Hub

1 2 3 4 5 6 7 8

PWR			AUTO				10Mb			RX
LINK		RX	LINK
										UPLINK
1	2		1	2	3	4	5	6	7	8

10Base-T

Internet

Router

100Mb Servers and Workstations

100Mb Fiber Link

	15E
Magnum	Converter			LINK
		0
Media	10		Mb/s	PWR
	GA RRETT

100Mb Media Converter

10Mb Workgroup

Figure 2.4d: The Magnum 528 provides 100Mb ports for backbone connections.

GARRETT

12