UC Architecture & Design : Deep understanding of Unified Communications Products like CUCM, CUC, IM & Presence, and Expressways. Deep knowledge of designing and troubleshooting clusters, inter-cluster trunks, and high availability configurations.
PSTN Trunking & Interoperability : Designing and troubleshooting SIP trunks, PRIs with carriers, including codec negotiation, SIP headers, PRIs, and call routing logic.