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Relay & CoT routing

Run an AryaOS box purely as a Cursor on Target (CoT) router. Select the relay role and the device stops all sensors, dedicating itself to moving CoT between networks and TAK Servers through the COTBridge hub.

Use a relay when you need to carry the picture, not make it. Bridge a Mesh SA group to a TAK Server, join two networks, or place a forwarding node at the edge of a MANET.

What COTBridge is

COTBridge is the CoT bridge/router at the heart of every AryaOS box (named for the ferryman - it ferries CoT). Every local feeder sends to COTBridge, and COTBridge owns all egress:

  • It listens for CoT on udp+ro://127.0.0.1:28087 (the site-config COT_URL default that feeders target with udp+wo://127.0.0.1:28087).
  • It forwards through the primary site-output lane. That lane multicasts to Mesh SA at udp+wo://239.2.3.1:6969 by default and can instead reach a TAK Server over TLS. Advanced configurations can add more lanes.

On AryaOS, COTBridge is configured at /etc/cotbridge.ini and edited from Cockpit > COTBridge at https://<host>/admin/. See COTBridge lanes for the full editor reference.

Lanes: ingress > egress

A lane is a one-directional route with an ingress_cot_url (where CoT comes in) and an egress_cot_url (where it goes out), plus mode = forward. Enable or disable each independently.

/etc/cotbridge.ini (AryaOS default)
[cotbridge]
DEBUG = false

[lane:site-output]
enabled = true
mode = forward
ingress_cot_url = udp+ro://127.0.0.1:28087
egress_cot_url = udp+wo://239.2.3.1:6969
PYTAK_NO_HELLO = true

For a pure relay you typically change the ingress to a network source rather than loopback. Common patterns:

Bridge a local ATAK Mesh SA group up to a TAK Server.

[lane:mesh-to-takserver]
enabled = true
mode = forward
ingress_cot_url = udp+ro://239.2.3.1:6969
egress_cot_url = tls://takserver.example.com:8089
PYTAK_NO_HELLO = true

Accept UDP CoT from feeders elsewhere on the network and republish to mesh.

[lane:network-to-mesh]
enabled = true
mode = forward
ingress_cot_url = udp://:18087          # udp://:PORT ≡ udp+ro://0.0.0.0:PORT
egress_cot_url = udp+wo://239.2.3.1:6969
PYTAK_NO_HELLO = true

Egress to a TAK Server via a tak:// enrollment URL (needs pytak[with-aiohttp,with-crypto]).

[lane:mesh-to-tak]
enabled = true
mode = forward
ingress_cot_url = udp+ro://239.2.3.1:6969
egress_cot_url = tak://com.atakmap.app/enroll?host=takserver.example.com&username=USER&token=TOKEN
PYTAK_NO_HELLO = true

PyTAK 7.x has no TCP listen

PyTAK 7.x does not support tcp+ppt:// (TCP listen). Use tcp://host:port only as an outbound client to a service that is already listening. To ingest from many clients, use UDP or a TAK Server.

Turn on the relay role

  1. Open Cockpit > AryaOS Site (https://<host>/admin/).
  2. In the Device role card, choose Relay - CoT routing only.
  3. Click Apply role.

All sensor units are stopped. COTBridge (and the position core) keep running.

sudo aryaos-role set relay

A relay still beacons itself

The relay role only disables sensors. cotbridge, lincot, gpscot. gpsd stay running. Thus, the relay node still routes CoT and reports its own position to the map. See Own position / GPS.

When to use a relay

  • Uplink node. A box with backhaul (Ethernet/LTE/satellite) bridges a disconnected team's Mesh SA to a distant TAK Server.
  • Network bridge. Join two segments - for example a MANET and a command LAN - passing CoT between them.
  • Fan-out / consolidation. Collect CoT from several feeders and forward one consolidated stream upstream.
flowchart LR
    subgraph Edge["Disconnected team"]
      E1[ATAK] 
      E2[AryaOS sensor box]
    end
    E1 & E2 -->|Mesh SA 239.2.3.1:6969| R[AryaOS relay<br/>COTBridge]
    R -->|TLS lane| S[(TAK Server)]