In Avaya's deployments, what role does 'Gateway' serve?

The role of the 'Gateway' in Avaya's deployments is primarily focused on converting signaling and media between different protocols. This is crucial in environments where various communication protocols need to interact seamlessly. Gateways are designed to facilitate communication between different networks and systems, enabling calls and data to pass from one protocol to another without loss of information or quality.

In the context of Avaya systems, gateways can manage multiple types of traffic, including voice and video, and can translate between the commonly used protocols such as SIP (Session Initiation Protocol), H.323, and traditional PSTN (Public Switched Telephone Network) signaling. By performing this conversion, gateways allow for interoperability between diverse network and device types, thereby ensuring a more integrated communication environment.

The other options, while relevant to broader network functionality, do not accurately define the primary role of gateways in Avaya deployments. Security features are typically handled by dedicated security appliances or software solutions, user subscription management is handled by application servers or administration interfaces, and connectivity between network types is a function of gateways, but their more critical role lies in protocol conversion.