A single Universal Messaging server has no hard limit set on the number of client connections that can be made to the server. Universal Messaging servers are implemented using Java's NIO (non-blocking IO) for all client communications including SSL. This means that there are no additional threads created and dedicated to each new client connection.

Universal Messaging messaging can be achieved across multiple server instances either by the use of a federated name space (see Federation Of Servers) or by using a Universal Messaging Cluster (see Clusters: An Overview).

Universal Messaging servers are aware of each other within a name space. Universal Messaging channels can appear in multiple places in a single name space allowing Universal Messaging to be infinitely scalable. In addition, Universal Messaging's licensing model places no constraints on the number of message servers run. Instead it is based on the number of channels used, thus allowing your client numbers to scale massively without additional cost.