Can you explain the "registered devices" limitations on performance (350,000)?

[Admin]

FreeSBC supports up to 350,000 registered devices. This limit is due to the fact that FreeSBC keeps the information related to the registration of VoIP user agents in memory so that it can refresh these registrations on behalf of the registrar, which is typically a softswitch. It should be noted that FreeSBC is not a registrar. Instead, it forwards REGISTER requests to the registrar. But it can also refresh the registrations and throttle REGISTER requests so the registrar does not get overloaded.