URL Blocking vs. Content Filtering
Novell Cool Solutions: Feature
By Scott Jones
Digg This -
Posted: 3 May 2002
The terms "URL blocking" and "content filtering" have been used interchangeably around here for quite some time. That's worked so far because all Novell BorderManager has done is URL blocking. That won't always be the case. So let's establish some definitions now and get thinking in the right mode for what's to come.
URL Blocking - This is what we do now with SurfControl. Requests are checked against a database to determine if the URL is allowed or denied. If it's denied, the dialog is killed before the request leaves the private network. This is highly efficient, but has limitations. Content can't be blocked in this manner unless it's already been identified and included in the URL database. Also, it's an all-or-nothing approach; the customer does not have the flexibility of saying, "ok, allow news sites but block advertisements and active content in those pages."
Content Filtering - With content filtering, the request has been allowed but the response is inspected at the proxy server. The actual payload of the packet is examined to determine if it contains anything meeting configured criteria. An allow/deny decision is then made. This provides the ability to block viruses, e-mail attachments, advertisements, redirects, web bugs, cookies, Java, ActiveX, pop-ups, media types and embedded objects, etc., etc., etc. Content can be examined without having to know anything about the origin server, and certain types of content can be removed from pages that are intentionally allowed by URL blocking.
The two are not mutually exclusive! They are complementary. Together, URL blocking and content filtering offer a more complete Internet access control solution for the customer. The majority of undesirable traffic is killed quickly and efficiently by URL blocking on the outbound path. The rest is caught on the return path. The customer also has the flexibility to allow access to a site but selectively block certain content from that site.
So start right now by thinking of SurfControl as URL Blocking. And we'll keep you posted as true content filtering solutions become available.
Novell Cool Solutions (corporate web communities) are produced by WebWise Solutions. www.webwiseone.com