Charter communications is blocking magic jack calls to my Mom house. LEGAL?

Wait a minute... your ISP says Charter is blocking MJ. But if I'm understanding your story, Charter IS your ISP. You have no confidence in Charter, but you put your faith in a $20 device? MJ doesn't use a "port" any different than a web site like Yahoo. It works over the internet. It's Voice over INTERNET PROTOCOL. Charter literally cannot tell the difference between a data packet from your MJ and a packet from your web browser. Do some research before you talk trash. Have you considered the possibility that there is a problem with your mother's telephone service? Have you called her from a different phone, like a cellular or real land line? I worked in the cable industry, and in the POTS telephone industry before that, and have more than twenty years experience in telecommunications. (I didn't work for Charter.) Your comment about cable companies pissed me off. You don't know what you're talking about, and that will be obvious to anyone reading your question who has a modicum of knowledge about telephony and/or how the the internet works.

i would assume that this has more to do with magic jack not paying interconnect or termination fees to charter, and that the trouble lies with magic jack... i would not be so quick to put the blame on charter... as for the word "port" in the telephone industry, that term is generally used to transfer an existing number from one carrier, or telephone service, to another carrier or telephone service..

Confirming with your ISP? Just throwing words around...do you know what ISP stands for? It mean internet service provider...And if you have Charter...they ARE your ISP. Unless you just decided to go with two different ISP's, which is ludicrous. Magic jack is a piece of crap, unreliable phone service. Charter doesn't block ports, and you can usually only unblock them through a router anyways. Which you are most likely using...And they're right. We don't know what ports do what, except for emails, and if you're lucky like me, the PS3 and Xbox ports.