Reasons why you need Chaperon
for ISA Server
WEB FILTERING - A NEW BREAKTHROUGH
Internet access has become a vital tool for
boosting the effectiveness of both private businesses and government
organisations. Not only can Web access be used for quickly researching
new technologies and product opportunities, it also provides immediate
fingertip access to a plethora of competitive and market trend
information. Other Internet services such as e-mail and newsgroups
allow greatly improved communication with customers and colleagues
to enhance both the speed and quality of business dealings. In
addition, the rise of e-commerce capabilities has for many businesses
moved the Internet from a peripheral support function to a core
component of their overall business strategies.
Here again, the downside of providing widespread employee access
to the Internet is the potential for abuse. From a business standpoint,
the major concern is the risk of productivity losses resulting
from staff using valuable work time to surf the Web or access
personal services such as travel sites, on-line gambling, and
chat services. Even access to relatively benign sites such as
streaming audio music services, while perhaps not directly effecting
productivity, can pose a significant drain on the company's available
bandwidth and computing resources. In addition to managing productivity
and resources, businesses must also protect themselves from the
potential legal liabilities of inappropriate access, such as sexual
harassment lawsuits that could arise from an employee's unauthorised
access and display of pornographic materials using the company
Internet connection.
As the variety and types of Internet content have proliferated,
the issue of access control has expanded well beyond just HTML-based
Web content, although Web filtering has remained the primary focus
of most previous-generation products. Unauthorised access to non-Web
Internet services such as ICQ® and IRC chat, FTP downloads, RealAudio®
broadcasts and MP3 music can easily consume significant bandwidth
and resources while degrading employee productivity, all without
triggering any access control mechanisms in traditional Web filtering
products.
Deployment Scenarios
In parallel with the evolution of filtering methods,
the deployment scenarios for access control software have also
evolved to better meet the needs of larger organisations such
as businesses and educational institutions.
Local Client Filtering Software
The first wave of Web filtering products primarily used
a client-side paradigm in which the filtering engine itself resides
on the desktop computer, either as a plug-in to the browser or
as a standalone program. These desktop-centric Web filtering products
operate in a similar fashion to anti-virus programs that monitor
the local machine's activities and conduct blocking based upon
the current listings in the local database. Periodic updates to
the local client's filtering database are performed by downloading
new data from a master database. Although such client-side deployment
has become quite popular for consumer-oriented Web filtering,
it has a number of shortcomings when used in a larger organisational
environment. First, the coordination and effort involved with
updating many different desktop-resident databases can present
a difficult challenge in large environments leading to outdated
and/or inconsistent filtering. Second, the fact that the Web filtering
software resides on each user's computer makes it more vulnerable
to tampering or circumvention. In addition, because the filtering
software is tied to each individual machine, it is not possible
to easily provide special permissions for roving individuals (such
as teachers) or different permissions for multiple people who
share a single PC.
Server Software Filtering Engines
The advent of Web filtering software for servers has
positively addressed some of these issues. Typically, such a server-based
filtering engine would be installed on an existing applications
server, either as a proxy server or as part of a firewall, to
provide screening and filtering for the entire network. By automatically
intercepting all packets requesting external Web-based content,
the server-based filtering engine can then block all inappropriate
content for the entire network from a unified central location
using a single database.
Return to Chaperon for ISA Server Internet content
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