Interconnection of broadcast networks

A method for propagating packets by a gateway, each of said packets comprising a source address and a destination address, said method characterized by the steps of

• configuring said gateway to implement the routing algorithm of forwarding any of said packets received by said gateway except for any of said packets having a destination address appearing as the source address in any previously routed ones of said packets, said source appearance being stored in a drop list;
• and, for each packet,
• extracting said source address and said destination address from said packet within said gateway;
• if said source address is not in said drop list, adding said source address to said drop list,
• if said destination address is not in said drop list, storing said packet for a predetermined time interval whereon subsequent ones of said packets are processed by said gateway;
• and
• routing said packet if said destination address is not in said drop list after said time interval;
• otherwise, no longer storing said packet within said gateway.

A method for processing a packet by a first gageway from a gateway pair wherein said first gateway has a first drop list readable by the second gateway and said second gateway has a second drop list readable by said first gateway, said packet comprising a source address and a destination address, each said drop list comrpising source addresses of previous packets processed by the corresponding gateway, and said method characterized by the steps of

• extracting said source address and said destination address from said packet within said first gateway,
• if said source address is not in said first drop list, inserting said source address in said first drop list,
• reading said second drop list and, if said destination address is in said second drop list, forwarding said packet by said first gateway,
• if said source address is not orignially in said first drop list and said destination address is not in said second drop list, storing said packet by said first gateway for a predetermined time interval wherein subsequent packets are processed by said gateway pair, and
• forwarding said packet if said destination address is not in said first drop list after said interval;
• otherwise, no longer storing said packet by said first gateway.

A method for transmitting a packet over a system comprising a plurality of networks interconnected by gateways, said packet originated by a source device connected to one of said networks and destined for a destination device connected to one of said networks, said packet including a source address and a destination address, and said method comprising the steps of

• defining an undirected graph representative of the system wherein said networks map onto graph nodes and said gateways map onto graph paths,
• defining a spanning tree on said graph such that every pair of said nodes is connected by only one of said paths and selecting a plurality of spanning trees for said graph according to predetermined system guidelines,
• configuring each gateway with source address lists in correspondence to the number of trees having said each gateway comprising one of said paths,
• assigning, by said source device, one of said trees to broadcast said packet and associating with said packet an identifier indicative of said one of said trees,
• broadcasting said packet by said source device through the system on said one of said trees,
• for each gateway receiving said packet,
• (i) determining for each said packet said source address, said destination address and said packet identifier,
• (ii) if said receiving gateway does not process packets having said identifier, inhibiting forwarding of said packet;
• otherwise, inserting said source address in the corresponding one of said lists associated with said identifier
• (iii) inhibiting forwarding of said packet if said destination address is in said corresponding one of said lists;
• otherwise, storing said packet for a prescribed time interval and then submitting said packet for processing by step (iv), and,
• (iv) inhibitng forwarding of said packet if said destination address is in said corrsponding list;
• otherwise, forwarding said packet by said receiving gateway, and
• acknowledging the reception of said packet by said destination device by broadcasting a return packet over said one of said trees.

A method for transmitting a packet over a system comprising a plurality of networks interconnected by gateways, said packet orginated by a source device connected to one of said networks and destined for a destination device connected to one of said networks, said packet including a source address and a destination address, and said method comprising the steps of

• defining an undirected graph representative of the system wherein said networks comprise graph nodes and said gateway comprise graph paths,
• defining a spanning tree on said graph such that every pair of said nodes is connected by only one of said paths and selecting a plurality of spanning trees for said graph according to predetermined system guidelines,
• configuring each gateway with source address lists in correspondence to the number of trees having said each gateway comprising one of said paths, wherein said lists reduce to a common list whenever said selection of spanning trees results in identical ones of said lists for said each gateway,
• assigning, by said source device, one of said trees to boradcast said packet and associating with said packet an identifier indicative of said one of said trees,
• broadcasting said packet by said source device through the system on said one of said trees, and
• for each gateway receiving said packet,
• (i) determining for each said packet said source address, said destination address and said packet identifier,
• (ii) if said receiving gateway does not process packets having said identifier, inhibiting forwarding of said packet;
• otherwise, inserting said source address in the corresponding one of said lists associated with said identifier, and
• (iii) inhibiting forwarding of said packet if said destination address is in said corresponding list;
• otherwise, forwarding said packet by said receiving gateway.