I have an Asterisk box serving an office of people. I'd like to provide instant messaging and file sharing capabilities alongside the voice and video capabilities provided by Asterisk (ala Windows Live Messenger, Skype etc). Asterisk does not seem to offer IM outside the context of a SIP call, nor am I aware that it provides file transferring capabilities whatsoever. The clients will be using Jitsi, so there are many protocols to choose from, but I'd like to provide as much integration as possible between the VoIP and IM/file transfer (ideally a single account that facilitates voice/video and IM/file transfer). Is this possible, and if not, what would be the most appropriate alternative?