Antonelli, Terry, Stout & Kraus
Network system
 In a network system having a plurality of LANs each connecting a plurality of terminals interconnected, a LAN interconnection switching unit for switching and relaying data receives data frames from LANs and sends out a call set-up frame including a call number assigned to a combination of source and destination terminal addresses and addresses of relaying interconnection switching units. The data received from LAN is segmented into packets, which are sent out together with the call number. The interconnection switching unit switches and relays data by using data frame error detection scheme in the LAN. Information for controlling a switching sequence is added to the data frame from the LAN to prevent the interruption by the packet having a different call number. 
Hitachi, Ltd.
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inventional inventional inventional
Michio Takahiko Yoshihiro Masashi Toshiki
Asano Kozaki Takiyasu Ohno Tanaka