Abstract: TML (Transport Mapping Layer) is the ForCES (Forwarding and control separation) protocol message transporting layer in the ForCES framework. Its communication performance will directly affect the efficiency and availability of ForCES NE (Network Element). In this study, the congestion control mechanism of SCTP (Stream Control Transmission Protocol) transport mapping layer is introduced and in a stochastic network calculus framework, the service model and service curve of SCTP which is in the congestion avoidance state by using the AIMD (Additive Increase and Multiplicative Decrease) algorithm is studied. At the same time, based on the EBB (Exponentially Bounded Burstiness) input model, the stochastic performance is also analyzed and the bounds on backlog and delay are derived. Numerical examples are presented to test the bounds. These performance analysis results can be used to optimize the SCTP TML to improve the efficiency of the ForCES communication channel.