Hello, Kamailio can be used as a SIP softswitch, of course. But the feasibility in your situation depends of course on your detailed requirements. You can handle high load with Kamailio on standard servers without any problems, 1000 concurrent calls should not be a problem. If you have a sustained load of 1000 call setup/s, you will need to do some tests. In the end this depends mostly then on other I/O related questions like database access time etc.. Cheers, Henning ________________________________ Von: sr-users <sr-users-bounces(a)lists.kamailio.org> im Auftrag von Mary Honey <maryhoneyplus(a)gmail.com> Gesendet: Sonntag, 16. Juni 2019 06:15 An: Kamailio (SER) - Users Mailing List Betreff: [SR-Users] Softswitch Hello, Is it possible to use Kamailio as a grade 5 Softswitch ? I need to handle 1000 calls/s