I have one internet connection upstairs that is hooked up to my computer and vonage and wireless router that goes down stairs wtih a cat 5 line to my home office where I have another vonage box. My mother inlaw is moving in can I hook up another line running from her vonage box to my computer/vonage? I have been trying but I can get everything to work... is there such a thing as a cat five spltter that I can use?