We are currently integrating Retell into a real-time voice setup (SIP + PBX... Retell AI #❓・ai-evy-support

We are currently integrating Retell into a real-ti...

dropsofsteel

01/04/2026, 5:20 PM

@AI Evy We are currently integrating Retell into a real-time voice setup (SIP + PBX), and latency is critical for us to ensure a natural conversation experience. Could you please clarify: In which regions are Retell’s real-time voice / audio processing servers primarily located? Is there a specific recommended region (e.g. US East, US West, EU) for deploying SIP/PBX infrastructure to minimize round-trip latency with Retell? We are not asking for exact data center addresses - just the general region(s) used for production traffic. This information will help us place our proxy/PBX infrastructure correctly and avoid unnecessary audio latency.

AI Evy

01/04/2026, 5:20 PM

Thanks for tagging me @dropsofsteel. I'll look through relevant sources and get back to you shortly.

AI Evy

01/04/2026, 5:21 PM

### Answer The available documentation doesn't specify which geographic regions Retell's real-time voice/audio processing servers are located in, nor does it provide a recommended region for deploying your SIP/PBX infrastructure to minimize latency. What I can share from the documentation: SIP Server & IP Information: - Retell SIP server URI:

sip:sip.retellai.com

[(1) ]() - IP block for traffic:

18.98.16.120/30

(All regions) ,

143.223.88.0/21

(United States only) ,

161.115.160.0/19

(United States only) - Note: Some non-US traffic might go from IPs not listed above, but will be migrated to the first IP block by 12/03/2025 Latency Benchmarks: - Retell AI typically achieves ~620-800ms end-to-end latency and ~180ms time-to-first-token [(2) ]() [(3) ]() - Testing was conducted from US East, US West, and EU regions [(2) ]() For specific guidance on optimal regional placement of your infrastructure, I'd recommend reaching out directly to Retell AI: - Visit [Contact Sales]() - Check out [) Check out these potentially useful sources: [Custom Telephony Overview]() Would you like me to provide a general answer based on common practices for minimizing SIP/VoIP latency?

AI Evy

01/04/2026, 5:21 PM

To learn more, see the sources I considered: [[1] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) [[2] ](https://www.retellai.com/resources/ai-voice-agent-latency-face-off-2025) [[3] ](https://www.retellai.com/resources/sub-second-latency-voice-assistants-benchmarks)

AI Evy

01/04/2026, 5:21 PM

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

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