Method for determining connection topology of home network
View Patent ↗A method is provided in order to determine connection topology of a home network. The main idea of the present invention is to send out a topology determination message on each link of the network, wherein the topology determination message is constituted of two consecutive packets, first one being a broadcast packet with a predetermined payload that identifies it as a topology determination packet, and second one being a unicast packet with the same content and a non-existent destination MAC address. If a node receives both the broadcast and unicast packet from a sending node, the sending node is determined to be on the same physical link with said receiving node and the MAC address of the sending node is added into a local link nodes list of said receiving node, otherwise if said receiving node receives only the broadcast packet from the sending node, the send node is determined not to be on the same physical link with said receiving node.
1. A method for determining connection topology of a home network, comprised of a plurality of nodes organized around multiple hubs and switches, comprising steps of:
transmitting a topology determination message including two consecutive packets in a random sequence one by one by each of the plurality of nodes, wherein, first one of the two consecutive packets being a broadcast packet with a predetermined payload identifying it as a topology determination packet, second one being a unicast packet with the predetermined payload and a non-existent destination MAC address, and the broadcast packet and the unicast packet of said topology determination message are sent one after another without collisions or other packets between them;
determining, by each of the plurality of nodes, the connection topology of all the nodes one by one upon reception of the broadcast packet and the unicast packet of the topology determination message;
generating and updating, by each of the plurality of nodes, lists of local nodes of all the nodes;
wherein
the connection topology of all the nodes are determined based on following rule:
i) if a receiving node receives both the broadcast packet and the unicast packet from a sending node, the sending node is determined to be on a same physical link with said receiving node.
2. The method as claimed in claim 1 , wherein if said receiving node receives only the broadcast packet, the sending node is determined to be not on a same physical link with said receiving node.
3. The method as claimed in claim 1 , wherein, the list of local nodes of the receiving node is generated and updated by adding the MAC address of the sending node into the list, when the sending node is determined to be on the same physical link with said receiving node.
4. The method as claimed in claim 1 , wherein a first timer (T 0 ) with a fixed time delay defining the whole duration of the process is provided.
5. The method as claimed in claim 4 , wherein a second timer (T 1 ) is provided, which is a random bounded time delay defining a time period between the beginning of the process and the starting of the transmitting of the topology determination message.
6. The method as claimed in claim 5 , wherein the maximum length of the second timer (T 1 ) is less than the length of the first timer (T 0 ).
7. The method as claimed in claim 5 , wherein a third timer (T 2 ) is automatically triggered each time said receiving node receives the broadcast packet from the sending node in order to define a duration intended to wait for the unicast packet.
8. The method as claimed in claim 7 , wherein the third timer (T 2 ) is less than the second timer (T 1 ).
9. The method as claimed in claim 7 , wherein the third timer (T 2 ) is less than a centisecond.
10. The method as claimed in claim 9 , wherein the second timer (T 1 ) is restarted with a new random bounded delay (T 1 ′), which is expired before the expiration of the first timer (T 0 ), if a collision of the topology determination message is detected.