Running a basic SIP load test from Asia/Singapore using JMeter with the SIP Sampler plugin. Trying to simulate 50 concurrent INVITE requests to a Genesys Cloud SIP trunk. The initial batch of 10 calls connects fine, but subsequent requests fail immediately.
Seeing 403 Forbidden responses from the Genesys Cloud SBC. The error log shows:
SIP/2.0 403 Forbidden Via: SIP/2.0/TCP 10.0.0.5:5060;branch=z9hG4bK-12345 Content-Type: application/sdp Content-Length: 0
Config details:
- JMeter Version: 5.6.2
- SIP Sampler: Default settings, no custom headers
- Auth: SIP URI authentication enabled
- Concurrency: 50 threads, 0 ramp-up, 60s duration
- Target: Genesys Cloud SIP Trunk (SBC IP: 15.16.17.18)
Suspect this might be a rate limit on the SBC or a concurrent call limit on the trunk. The trunk is configured for 1000 concurrent calls, so capacity shouldn’t be the issue. Is there a specific header missing or a timing constraint I need to respect in the JMeter script? What is the correct way to handle SIP 403 errors during high-concurrency JMeter tests against Genesys Cloud SIP trunks?