Specifications

9
Network design
Because a RAVE network uses a 100baseTX Fast Ethernet medium, you would generally use the same approach
to designing the RAVE network as you would for a computer network.
There are several ways to configure a RAVE network, from very simple to relatively complex. The number of RAVE
units in the network, where they are located, and your future expansion plans will determine what net topology
would be best. The same techniques you would use in designing a conventional 100-Mbps Fast Ethernet will assist
you in designing a RAVE network.
HARDWARE AND MEDIUM CONSIDERATIONS
RAVE units can use unshielded twisted pair wiring, but it must be at least Category 5 quality. Anything less may
cause unreliable operation of the network, if it runs at all. Fortunately, most new Ethernet cable installations
in buildings use Category 5 cable.
Cascading hubs with uplink ports
Cascading hubs without uplink ports,
using crossover cables
Most RAVE networks will require one or more hubs, which must be
compatible with 100baseTX Fast Ethernet. The next chapter will show
how these hubs are used. A hub is primarily a repeater with multiple
ports; any data that comes into one ports gets simultaneously distrib-
uted to all the other ports. A RAVE network will not work with the more
common 10baseT hubs, which can only handle 10 megabits per second.
Fast Ethernet hubs also cost more than the lower-speed versions, but
like any other computer equipment, the performance-to-price ratio is
continually getting higher and higher. In fact, whatever you spec today,
you’ll probably find an even better deal next month or even next week.
At some point, though, you have to say this is what you need now, and
go with it.
Most hubs have a port for uplinking or cascading to another hub. So if
you have a six-port hub, for example, with all six ports connected to
RAVE units, and you need to add a couple more RAVE units to the
network, you don’t need to replace the original hub with one having
more ports. All you need to do is add another hub, connect it via an uplink
port to the other hub, and hook up the new RAVE units. If your hubs have
no uplink ports, you can do the same thing by using a crossover cable
to interconnect the hubs.
Fast Ethernet techniques for operating over longer distances (>100
meters from RAVE unit to hub), such as conversion to a fiber optic
medium, are also compatible with RAVE hardware, although the RAVE
units themselves connect only via 100baseTX cabling. As with hubs,
higher performance is always becoming more available and more
affordable.