Starting Friday, Wilmington, Mass.-based Astaro is to customers who switch to its products. The "Sonic Switch" promotion, which was announced Thursday, is slated to run through the end of January and applies to all of Astaro's security appliances.

Astaro is a maker of a so-called devices that combine network, Web access and e-mail security functions into one box. Like Sunnyvale, Calif.-based SonicWall, Astaro sells mainly into the small and midsize business markets; most of their customers have between 50 and 500 users, although both vendors sell products to larger companies as well.

Angelo Comazzetto, a product manager at Astaro, said the trade-in promotion is designed to tap into the disgruntlement that the license server glitch caused among SonicWall users. "We are trying to capitalize on the customer sentiment," he said.

The 50% discount off list price can be had on all of Astaro's hardware and software, plus its maintenance contracts, Comazzetto said. In addition, Astaro will honor the existing support contracts of SonicWall customers to ensure that the users don't lose any money in the deal.

A technical problem in one of SonicWall's license servers left many of its customers unprotected against spam, and threats for several hours on Tuesday, while other users were unable to log into their own systems.