Probably, but it depends on what he had at the time from Cisco. All he really needed was a connection to the Internet. I will say that there are some possible complications that TWC was the phone provider. For most intended uses, it is just like any other phone, but I tried to hook up a fax to mine a couple of weeks ago, and it would not work. The fax said the phone was off-hook, even when it was not, so there are some differences. I have been able to get the fax to work with Vonage, but not TWC.
I feel sure this was not an insurmountable issue, given that he had used it previously. Also, for those of you keeping score at home, the confusion over the VTECH and VOIP phones is a moot point. TWC is a VOIP provider, and so was the CISCO system, the VTECH, as SG said in a prior post, is just a plain ol' phone, but hook it into the VOIP system and it becomes a VOIP phone.