Anyone using current PC technology has probably dealt
with networks at some point, but that experience is typically with internal
networks and applications. A central server, with many users connected
to that server sharing files and data, is the configuration that comes
to mind when envisioning a network.
Remote Networking, on the other hand, uses external WAN
communications links to other physical locations across town or across country,
and it is not always a simple task to design a system that can provide remote
sites with acceptable performance! The specific criteria that must be balanced
- Traffic is the foremost concern, as every external
link has a incremental cost, and for that cost a finite bandwidth. A normal
modem connection provides acceptable performance for a single remote user,
however that connection is seldom ideal (as most of you know, accessing this
screen via modem right now). The speed of that modem link is fixed, a current
top speed of 28.8 Kbps, and no more information can be squeezed into that
pipe in a given second.
- Application Design is also a critical factor, as the
amount of information that must be carried over the link is a fundamental
performance factor. Good client/server design can be utilized to minimize
the link traffic, however there are a number of gotcha's that must
be considered. A client/server design itself serves to provide an advantage
over other types of applications, as a client/server application utilizes
the network services for connections to the server and database. Other applications
must rely on sophisticated remote control programs that add another
layer of complexity and performance degradation.
- Communications Cost is driven by speed requirements.
If faster service is required, a more expensive connection must be utilized,
in which case the cost of that faster link must be justified. Basic modem
connections, typically suited to a single user, are not adequate when a remote
office is connected. That remote office might have five, ten, or more simultaneous
connections to the central office, not a very cost effective solution using
individual phone lines.
Faster communications is also required for more sophisticated
operations, such as the database synchronization facilities provided by the
current generation of relational database systems.