an arrangement for providing , on an ad hoc basis , a closed user group among a collection of pre - defined ip network users . a set of intelligent access devices , dispersed through the ip network , constantly transmit a set of pings associated with the defines cugs to discover those devices within its communication range . the discovered ip addresses for each device is thus constantly updated , allowing group members to remain in constant contact . the users feels they are always connected with group members and thus have instant access to voice / data / video sessions — much like hot lines or “ always on ” connections .