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Bridge image

sip-dmr-bridge runs as a Docker container per active call, spawned by the exchange.

Build

git clone https://github.com/FreeSTAR-Network/sip-dmr-bridge.git
cd sip-dmr-bridge
docker build -t sip-dmr-bridge:latest .

The image includes MMDVM bridge components from sip-usrp-bridge.

Exchange expects the tag configured in .env:

BRIDGE_IMAGE_NAME=sip-dmr-bridge:latest

Per-call behaviour

  • Exchange assigns unique MMDVM_BRIDGE_DMR_LOCAL_PORT from configured range
  • Container name typically based on callsign
  • HEALTHCHECK must pass before exchange connects SIP media
  • Container is removed when the call ends

Resource usage

  • ~130–150 MB RAM per container
  • CPU spikes during AMBE encode/decode and md380-emu

Plan host RAM as: (MAX_ACTIVE_CALLS × 150 MB) + ~1 GB exchange/OS headroom.

Updating the image

After pulling bridge changes:

cd sip-dmr-bridge
docker build -t sip-dmr-bridge:latest .

New calls use the new image; active calls keep running on the old container until hangup.

Last update: August 17, 2026 21:08:54
Last updated by: MØVUB
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