Compared with the access layer switch, the aggregation layer switch has stronger performance, higher port rate, fewer ports and higher packet forwarding rate. This article looks at what each such tool does, compares how they differ from each other, and offers suggestions as to what sort of network each. Your MS425's will be your core or in your case a collapsed core (aggregation and core) and the other switches will be your edge. Aggregation switches as the name implies aggregate multiple edge devices which are then passed through to your core. In the three-tier architecture, the role of the access layer is mainly to connect end users to the network. This switch is relative to some large, high-end switches. SMB switches support common Layer 2.