Substation communication network (SCN) is critical for the transmission of mission critical messages in IEC 61850 based digital substation automation applications. This paper presents the performance analysis of various substation communication network architectures, considering the IEEE/PSRC (Power System Relaying Committee) suggested traditional Ethernet switched networks such as star, ring, and star-ring. Further, the feasibility of the Substation Automation System (SAS) architectures in implementing crucial substation protection applications is analyzed by calculating ETE delay performance of time-critical Sampled Values (SVs) and Generic Object Oriented Substation Event (GOOSE) messages over SCN. OPNET (Optimized Network Engineering Tool) modeler is used to design, simulate, configure and study the dynamic performance characteristics of different SCN architectures drawn for a typical substation layout under normal as well as worst network traffic conditions.