| 主权项 |
1. A method for establishing loop free data communication between a first communication network and a second communication network via a dual homing (DH) connection, wherein the DH connection is formed by four nodes and a ring-like connection there-between provided by four communication lines, two of said lines being inter-network lines respectively connecting two inter-network pairs out of said nodes, wherein each said inter-network pair comprises nodes residing in different said two networks, and the remaining two of said lines being intra-network lines respectively connecting two intra-network pairs of said nodes called intra-network node pairs, wherein a first intra-network node pair resides in the first communication network and a second intra-network node pair resides in the second communication network, the method comprising:
ensuring that all the four communication lines are configured to carry data traffic to be communicated via the DH connection; locally running on each of the two intra-network node pairs an instance of a loop protocol via its associated intra-network line, independently from the protocol instance run on the other intra-network node pair of the DH connection; independently and dynamically selecting, by each of the protocol instances, a Primary node and a Secondary node in a specific intra-network node pair running the protocol instance; enabling each of the intra-network node pairs to utilize suitable inter-network and intra-network paths for carrying data traffic to be communicated via the DH connection; wherein said DH connection is adapted to operate in a symmetric configuration, where direct data communication is established between the Primary node of the first intra-network node pair and the Primary node of the second intra-network node pair, via an inter-network line out of said four communication lines, and in an asymmetrical configuration where indirect data communication is established between the Primary node of the first intra-network node pair and the Primary node of the second intra-network node pair, via inter-network and intra-network lines out of said four communication lines; and configuring said first intra-network node pair and said second intra-network node pair to implement traffic forwarding rules which are independent of whether the configuration of the DH connection is a symmetric or an asymmetric configuration, thereby ensuring that each Primary node is agnostic to whether it is connected to a Primary node or to a Secondary node of the other communication network, and each Secondary node is agnostic to whether it is connected to a Primary node or to a Secondary node of the other communication network; and avoiding duplication of traffic originating in one of said first communication network and said second communication network when said traffic needs to be conveyed from one of said communication networks to the other via said dual homing (DH) connection. |
