Licences can also limit the number of concurrent sessions or topics.

The Diffusion server includes a restricted default licence which allows you to evaluate the core features.

If you need to buy or upgrade a paid commercial licence, contact [email protected] . The sales team can also provide a more capable Evaluation licence if required.

Table 1. Licence capabilities

Feature	Restricted Default	Commercial	Commercial with Scale & Availability Pack
Core Diffusion features
Production use allowed?
Maximum sessions	5	Varies	Varies
Maximum topics	1000	Varies	Varies
Maximum CPU cores	8	Varies	Varies
Persistence
Remote connections (remote topic views and fan-out)
Session replication
Topic replication
Cluster management (including Prometheus)

Commercial licence restrictions

A specific commercial licence may have restrictions such as an expiry date, allowed IP range or a maximum number of concurrent sessions, depending on your agreement with DiffusionData. See Licence restrictions for details of possible restrictions.