[js3309]

I'm not sure if they infringe on the infrastructure level now because all their examples are very basic (making calls, receiving calls, forwarding calls and etc.) These have been patented and their terms have expired. I bet that's one of the reasons they only have basic examples on their site.

I'm not a litigation expert but if you were to build a feature that infringes on a patent you might be liable.

Below is a link to uspto telephony classifications. http://uspto.gov/web/patents/classification/uspc379/sched379...