Version
3.0 | Version
3.0 |
User's Guide |
4. Configuring NetProxy Services
4.3. World Wide Web (HTTP) Proxy Service
The world wide web (WWW) proxy service allows your network users to use web browsers to access the world wide web. The WWW proxy includes a cache feature which stores copies of frequently-accessed pages and images on disk. If a network user attempts to access a page that NetProxy has cached, the page is served directly from the cache to the user. This caching process provides significant performance gains and reduces the amount of time the NetProxy needs to remain online. NetProxy uses a complex set of algorithms to ensure that its cached resources remain up-to-date.
The configuration dialog for the WWW proxy service is shown below. Information on each setting is given below the picture.
Local Port
Specifies the TCP port number that the WWW proxy service should
run on. When configuring web browsers to use NetProxy, this port
must be entered as the HTTP proxy port.
Downstream Proxy Server
Enabling this option causes NetProxy to forward any requests for
pages not stored in its local cache to the specified remote proxy
server. If your Internet Service Provider has a caching proxy
server for customer use, entering the details here should offer
significant performance gains.
Enable Caching
When enabled, the caching option causes NetProxy to store copies
of frequently accessed pages on disk. Enabling caching is highly
recommended, as it will improve performance and reduce the amount
of time that NetProxy needs to remain connected to the Internet.
Local Cache Directory
Specifies the directory in which NetProxy will store cached WWW
resources.
Maximum Cache Size
This value specifies the maximum size, in megabytes, that the WWW
cache directory may grow to. NetProxy will stop caching web
resources when the cache reaches this size. 50MB is a sensible
minimum, but larger values will improve performance.
Expiry time for HTML
Documents
Specifies the maximum time, in hours, that an HTML (textual web
page) resource may be cached for before NetProxy must check for
updates. Note: this is a maximum figure. NetProxy's caching
algorithms may cause cached HTML pages to be updated at shorter
intervals to ensure stale pages are not served from the cache.
Expire time for 'other'
Documents
Specifies the maximum time, in hours, that non-HTML web resources
(such as images and Java applets) may be cached for before
NetProxy must check for updates. Note: this is a maximum figure.
NetProxy's caching algorithms may cause cached resources to be
updated at shorter intervals under some circumstances.
Tidy Cache
Causes NetProxy to run through its entire database of cached WWW
resources, removing any stale resources. For busy servers,
tidying the cache once per week will improve performance and
reduce disk space used.
Empty Cache
Removes all cached resources from NetProxy's cache directory.
OK Button
Closes the dialog box and applies any changes.
Cancel Button
Closes the dialog box and cancels any changes.
Apply Button
Applies any changes without closing the dialog box.