The present disclosure discloses an SCTP-based communications method and system, and an apparatus. The method includes: A network element selector receives an SCTP packet that includes a plurality of SCTP data chunks of a plurality of user terminals. Because each SCTP data chunk carries index information, the network element selector may select a service providing device for each user terminal based on the index information carried in each SCTP data chunk. Therefore, application layer messages of different user terminals in the SCTP may be routed to different servers based on LBI parameters, and corresponding session persistence is implemented in a subsequent interaction process.