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If you can log in and use Jam Assistant but voice calls won’t start - or the call connects for a few seconds and then ends automatically - the most likely cause is that your corporate network blocks the WebRTC connection used for real-time voice. This page explains how to diagnose and fix it.
Run the built-in connectivity checker first: app.wejam.ai/check. Microphone access is required for a full test.

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Symptoms

  • You can log in and use text chat normally.
  • Tapping the voice button fails immediately, or the call ends itself within a few seconds with an error such as “could not establish connection”.
  • The problem is consistent - it happens every time, not just occasionally.

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Likely cause

WebRTC voice traffic is not allowed on your company network, or the network blocks the signaling connection that starts the call.

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Background: how Jam Assistant uses the network

To load and use text chat, only TCP port 443 (HTTPS) is required. To create low-latency voice-to-voice interactions, Jam Assistant uses WebRTC through the ElevenLabs EU residency network. The browser must be able to complete WebRTC signaling on TCP/443 and send media traffic over UDP.
  • ElevenLabs powers the real-time voice AI. Jam Assistant connects to the ElevenLabs EU residency region for voice calls.
  • Signaling uses HTTPS/WebSocket traffic on TCP/443.
  • Real-time media uses WebRTC UDP traffic, including the standard dynamic UDP port range 49152-65535. Restricting UDP to only 40000-49999 can prevent calls from starting.

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Debugging steps

  1. Run the connectivity checker. Direct the user to app.wejam.ai/check (microphone access required). This tests the connection end-to-end and reports whether it’s the WebRTC/media path or the signaling path that’s blocked.
  2. Whitelist the required domains and ports on the corporate firewall or proxy:
For ElevenLabs domains, the firewall must allow WebSocket upgrades on TCP/443 and WebRTC media traffic over UDP. Blocking either the signaling connection or the UDP media path can make a voice call fail before it starts, or end it a few seconds after connecting.

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Network requirements (for IT teams)

Jam Assistant’s voice calls use low-latency WebRTC connections, facilitated through ElevenLabs EU residency infrastructure. To ensure reliable operation, the following must be supported in the customer’s network environment: Port accessibility
  • TCP port 443 is required for HTTPS and WebSocket signaling.
  • UDP ports 49152-65535 must be allowed for WebRTC media traffic to ElevenLabs. This is the standard dynamic UDP port range used by WebRTC; observed calls may use ports such as 50674 or 53396.
Domain whitelisting
  • link.wejam.ai - Jam Assistant web app
  • app.wejam.ai - Connectivity checker (/check)
  • api.wejam.ai - REST API
  • eu.residency.elevenlabs.io - ElevenLabs EU residency service
  • rtc.eu.residency.elevenlabs.io - ElevenLabs WebRTC media
  • livekit.rtc.eu.residency.elevenlabs.io - ElevenLabs SDK WebRTC media
  • api.eu.residency.elevenlabs.io - ElevenLabs API/signaling
Prefer FQDN-based allowlisting for ElevenLabs. Their infrastructure can resolve to changing IP addresses, so IP-only allowlists are more likely to break. Corporate network considerations Restrictive network environments, such as those common in corporate settings, may impede WebRTC connectivity. In those cases the customer is responsible for ensuring the network supports the required configuration, including allowing the domains above, WebSocket upgrades on TCP/443, and UDP media traffic in the dynamic port range. Diagnostic tool Use the built-in connectivity checker at app.wejam.ai/check to diagnose connectivity issues. The page checks microphone access, the JAM API connection, an ElevenLabs WebRTC connection, and a short voice test through an echo agent. Microphone access is required for a full test.
Last updated: August 2026