Located throughout the lab are outlets with RJ45 jacks which are wired to the campus network. There is one near each computer in the lab, connected to one of the computer's Network Interface Cards (NICs) with a grey cable. In addition there are a few jacks available for connecting laptop computers to the campus network. The connections between the computers and the public network jacks should be left as they are.
Located throughout the lab are outlets connected to the private network. Each outlet has two RJ45 jacks - one blue and one orange. The outlets are numered 1 through 23. The number is written on the outlet. The private network wiring connects these outlets to distribution panels mounted on racks located in the corner of the room. The distribution panels are colored blue and orange to correspond to the jacks in the outlets. The blue jack in outlet 3 is connected to jack 3 in the blue distribution panel, and the orange jack in outlet 3 is connected to jack 3 in the orange distribution panel. There is no significance to the colors (blue and orange) other than to allow the corresponding jacks in the outlets and the distribution panels to be easily distinguished. The cabling that connects the outlets to the distribution panels is category 5 cable in which there is no crossing over of the individual strands (i.e. it is straight through).
Cables to connect the private network outlets to network interface cards on
the computers
are left in place. A blue cable is connected to the blue jack and a yellow
cable to the yellow jack.
Computers
There are 23 computers in the lab. Each is located near one of the private
network outlets. In identifying these computers each is assigned the
number of the nearest outlet.
Each computer has 4 network interface cards. One is in the first ISA slot. The others are in the last 3 PCI slots. The first is connected to the public network. The other 3 network interface cards can be connected to the private network. If only one or two network interface cards are needed for an experiment, they should be connected to the nearest private network outlet. Cables for this purpose are left connected to the private network outlets - a blue cable for the blue jack and a yellow cable for the orange jack (yellow, not orange, because the cables were donated and yellow was the color closest to orange from what was available). To avoid confusion these cables should be left connected to the jacks of the corresponding color. All adjustments should be made by changing which network interface card each cable is connected to. If an experiment requires all three network interface cards, then the third connection must be made to another outlet that is close enough for its cable to reach.
There is one additional computer in the lab whose sole function is as a
server
for use on the private network. This computer has 2 network interface
cards.
There is no private network outlet for use with this server. Instead the
server is located very near the racks containing the distribution panels
and the network hardware. Two cables are left connected to the network
interfaces of the server. These cables are long enough to reach the ports of
any of the network devices in the racks.
Network Equipment (Hubs, Switches, Routers)
All the network equipment is housed in
racks
in a corner of the lab.
Two racks are left permanently in the lab.
The equipment in these racks includes:
Most of the network hardware can be managed through a serial connection
to a terminal or to a computer running a terminal emulator. On one rack
is a
distribution panel for serial connections
to the five nearest
computers (those numbered 13 through 17). As you face the computers and
the racks the computer on the left (number 13) is connected to the
leftmost serial connector on the panel, and the remaining computers are
connected in order to the remaining serial connectors on the panel.
The connection on these computers is to COM port 2.
Power Issues
There are 3 20-amp circuits available for the network hardware. One circuit
(circuit 1)
is connected to the power strip behind computers 13 through 17; one
circuit
(circuit 2)
is connected to the two leftmost receptacles in the
wall outlet
near the racks; one circuit
(circuit 3) is connected to the two rightmost receptacles in
the wall outlet near the racks.
Each rack has a power strip with a master switch that controls power to all the receptacles in that strip. Every piece of equipment in the lefthand rack that has its own power switch (which is every piece of equipment except the 3COM CoreBuilder 3500) is connected to the power strip in that rack, which in turn is connected to one of the lefthand receptacles (circuit 2) in the nearby wall outlet. To use any of these pieces of equipment the switch on the power strip must be on (and lit) and the power switch on the equipment itself must be on (on the equipment the symbol "|" or "-" indicates "on" and "O" indicates "off"). All the equipment in the righthand rack is similarly connected, but to one of the righthand receptacles (circuit 3).
When you power off the power strip for a rack, be sure that each piece of equipment in the rack is powered off first. Otherwise the next person to power on the power strip will provide power to equipment that he does not want to use.
The 3COM CoreBuilder 3500 has no power switch. If it were connected to the power strip on the rack there would be no way to use the other pieces of equipment without also powering on the CoreBuilder 3500. Therefore the CoreBuilder 3500s in both racks are plugged into an outlet on the back of the lefthand rack which in turn is plugged into the outlets behind the computers (circuit 1). There is a switch on the back of the rack that controls power to the two CoreBuilder 3500s.
When the mobile rack is present, its two Cisco 7000 routers are plugged into the wall outlet, each to a separate circuit.
It is important to avoid changing the way in which the equipment is plugged in. The total current drawn by all the equipment exceeds the 20 amp capacity of a single circuit and must be distributed among the three circuits so that none of the circuits is overloaded (as would happen if the power strips on both racks were plugged into a single circuit). [Click here if you are interested in more details on the current drawn by the equipment and how it was measured.]
