A hand held portable multipurpose demolition tool is powered by bottled compressed gas operating a pneumatic impact mechanism with interchangeable tools. This is realized by providing a supporting rod along an upward and downward movement locus of the glass plate and a contact member which has no contact with the supporting rod, by forming trumpet-shaped guide portions at hole edges of the wire fixing portions, and by V-shaping the circumferential surfaces of a tensioner for eliminating slack of the wires. The session request includes session information, media capabilities of a telephony client device associated with the at least one TCP, a list of WAN devices or a conference group identifier associated with one or more WAN devices, and a subject of the multi-media conferencing session.