1 translates in accordance with records 501 and 502 of table 400 2 the contents of the associated source and destination fields that is lam 210 1 deletes the message header and translates the destination address 60003 into common address 65000 and translates the source address 60009 into address 60005 lam 210 1 then passes the resulting message to port 2 and bus 300 21 for delivery to printer 300 50 as indicated by routing record 501 lam 210 1 performs the reverse translation in connection with a printer 300 50 message that lam 210 1 receives via bus 300 21 and the associated port 2 211 1 that is lam 210 1 based on routing record 502 translates the contents 65000 of the source field into address 60003 and translates the contents 60005 of the destination field into address 60009 lam 210 1 then attaches to the message a header containing the address and assigned channel number 7 obtained from routing record 502 and then passes the resulting message to lan gateway 200 for delivery to lam 110 1 via the aforementioned virtual circuit connection lam 110 1 responsive to receipt of a printer 300 50 message via lan gateway 100 deletes the message header.