This invention discloses a communication methods, servers, and terminals. Aspects receive an allocation request, used for registering and connecting to the communication network, of an identity identifier from a terminal; parse the allocation request of the identity identifier and acquiring an attribute information of the identity identifier; find, from a plurality of identity identifier candidates, an identity identifier matching with the attribute information of the identity identifier and regard the found identity identifier as the one to be allocated; read the data, used for registering and connecting to the communication network, of the to-be-allocated identity identifier, and send the data, used for registering and connecting to the communication network, of the to-be-allocated identity identifier to terminals.