Route diffusion method and device

The invention provides a route diffusion method, which is used for an embedded control channel (ECC) network, and comprises the following steps: a first network element receives a network element identifier of a second network element and a subnet identifier of a second ECC subnet so as to generate an inter-subnet route between a first ECC subnet and the second ECC subnet, the first network element is a boundary network element of the first ECC subnet, and the second network element is a boundary network element of the second ECC subnet; the first network element receives a request message from a first non-boundary network element, the request message is used for requesting to communicate with a target network element, the request message comprises a network element identifier of the target network element and a subnetwork identifier of a subnetwork where the target network element is located, and the first non-boundary network element is other network elements except the first network element in the first EC