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Tracelink User Manual 19
Switches
The aforementioned type of process, where the data is simply replicated onto
every available port, quickly becomes inefficient for larger sized networks. For
this reason, a larger sized LAN employs the usage of Switches instead of Hubs.
A Switch is essentially a smart Hub, in that it limits the input and output of data
to the two transacting computers.
Routers
Larger networks, such as Wide Area Networks (WANs), or the Internet for that
matter, use progressively more sophisticated devices to transact data. At the
core of these devices is the Router, which functions as a switch between
networks.
The Tracelink performs irrespective of the connection mechanism, with one very
important caveat: it needs to be set up with the appropriate network parameters for
the underlying network architecture.
5.2 Network Parameters
A typical network becomes operational not after the physical connections have been
established, but after network parameters in the form of IP (Internet Protocol)
numbers have been assigned to the individual computers. An IP number is a unique
string that consists of four numbers ranging between 0 and 255, separated by dots,
e.g., 192.168.1.2. Every computer that is on a network needs to have a unique IP
number. The computer uses this IP number to identify itself on the network, and also
to address the recipient of its data.
Assignation of this IP number is sufficient information to transact data on a simple
network connected by a hub. On a more complex network, however, routing
information becomes important. The routing information consists of two more IP
numbers. The first of these is called the Subnet Mask, and is used to determine
whether or not the destination address resides on the same subnet (i.e., doesn’t need
to be forwarded to another network). The other IP number is the Gateway Address,
which is the address of the computer that handles forwarding and receiving of packets
to and from other networks.
Before first use, the Tracelink needs to be programmed with a unique IP number, the
Subnet Mask IP number, and also the default Gateway’s IP number. This can be done
via the USB port and is described in greater detail in the “Configuring the Tracelink”
section of this manual.