SIP Trunking FAQs
TCP or TLS?
Prefer TLS on port 443 for production. Use TCP 5070 only if TLS is not available on your SIP stack.
Do I need IP whitelist and digest credentials?
| Scenario | Method |
|---|---|
| On-prem PBX / SBC with fixed IP | IP whitelist |
| Cloud platforms with dynamic IPs | Digest credentials |
| High-security production | Both |
What is pstn vs flow mode?
pstn— classic PSTN + Connect applet tosip:<trunk_sid>flow— Voice AI / StreamKit / App Bazaar applets (Voicebot, etc.)
See Call directions.
Where are TCP / TLS / FQDN setup guides?
On the docs portal under SIP Trunk Configuration. The developer portal focuses on APIs and first-call success.
Calls connect but there is no audio?
Open UDP 10000–40000 and allow Exotel media IPs — Network & firewall.
How do I get sample code?
github.com/exotel and the Quickstart curl examples.
Who do I contact?
hello@exotel.com — include Account SID, trunk transport, Call SIDs, and SIP traces.