Leadtek Research, Inc.

Leadtek no longer seems to make its ATAs, or, if they do, they're close to impossible to find on the Leadtek website. That being said, however, their ATAs were/are excellent products. With a web-based configuration interface and easy switching between SIP and PSTN, their ATAs have a lot to offer. The one main advantage of the Leadtek ATA over the Grandstream ATA is that the Leadtek can be configured to default to PSTN connectivity. With the grandstream models, if you have a model with PSTN passthrough, you need to hit a key or series of keys to switch to your home phone line (it always defaults to the SIP line). With the Leadteks that have PSTN passthrough, you can configure your device to either default to the local phone line or the IdeaSIP line.

The Leadtek BVA8051S has been tested extensively on the IdeaSIP network. However, it no longer seems to be available. If you can find a used one cheaply, it's definitely a recommended device. If not, there are plenty of currently-supported, inexpensive Grandstream models that will work just as well.