pbxnsip – SIP Connection Limit
pbxnsip limits the number of active SIP connections to 100. This is controlled by the “global settings” variable “sip_threads” and you can increase or decrease it based on your need. PBX restart is needed after this change. If you are using TCP/TLS for registrations, then you may bump into this issue.
Article on the global configuration file found at http://www.pbxnsipsupport.com
