Web logs provide a new avenue for network vendors to communicate with their customers. After all, blogs are immediate, informal, personal and interactive, and they can be fun and intellectually stimulating at the same time. What better way to break down the walls between corporation and customer?

At the same time, from corporate IT managers' point of view, vendor blogs can provide important information on industry trends, corporate direction and news about specific products.

We decided to take a look at blogs of 15 top networking companies and analyze them based on criteria we developed.

So, what are the characteristics of a good corporate blog? Customers are looking for "the real scoop" when they check out a corporate blog, says Debbie Weil, author of The Corporate Blogging Book. "The first thing you want to see is something you won't get on the regular corporate site. The built-in expectation is something more insider, something more direct, more revealing about the product or about the issue," she says.

In addition, a good corporate blog is easy to find, updated frequently, allows reader comment, analyzes issues important to customers and tells the truth about specific products -- positive or negative.

For example, Dell used its blog in August to smooth over a flap with customers about delays in a motherboard exchange program. Customers got detailed information on the exchange program, and some who complained in the public-comments section received direct responses from a Dell manager.

Some companies aren't as comfortable responding to customer complaints in a blog. HP LaserJet blogger Vince Ferraro answered numerous questions in July about printing problems that occurred when HP equipment was used on Microsoft Windows Vista. His blog posting, however, spurred HP to change its policy about responding to comments about product problems. The blogger now is prohibited from responding directly to comments that can be handled by customer service.