As TDM and IPv4 legacy communication technologies wave their long goodbyes, infrastructure and operations (I&O) professionals need to get reacquainted with a few previously hyped IP technologies. The likes of IMS and IPv6 are regaining mindshare, if not the spotlight, as enterprises seek to better enable their mobile workforces and proactively compete for and in new business markets. But don't expect simple plug-and-play solutions to fall into place; I&O professionals will have to negotiate tricky workarounds as these technologies mature.