Networking and firewall#

DeviceIOHub, CloudXR, and optional application viewers use the following ports. Open only the externally reachable ports required by the deployment.

Port

Protocol

Purpose

7880

TCP

Plaintext LiveKit signaling (used behind the hub’s /rtc proxy; optional direct native-client debugging path)

7881

TCP

LiveKit WebRTC TCP fallback (DTLS/SRTP — already encrypted)

7882

UDP

LiveKit WebRTC UDP media (DTLS/SRTP — already encrypted)

8080

TCP

Web client, token server, and wss:// /rtc proxy (HTTPS; the normal LiveKit signaling entry point for shipped clients)

8092

TCP

Optional live agent-event viewer (plain HTTP — bound to 127.0.0.1 by default; do not expose to an untrusted network)

48322

TCP

CloudXR WSS proxy (WebRTC profiles; unused by native Apple clients)

Ubuntu or Debian (ufw)#

sudo ufw allow 7881/tcp     # WebRTC TCP fallback
sudo ufw allow 7882/udp     # WebRTC UDP media
sudo ufw allow 8080/tcp     # https + wss entry point
sudo ufw allow 48322/tcp    # CloudXR (xr-render-demo)
sudo ufw reload

These rules intentionally omit port 7880. The generated LiveKit configuration does not set bind_addresses, and the container uses host networking, so the plaintext listener can accept connections on the host’s network interfaces. Merely omitting an allow rule protects it only when the host firewall and any cloud security group reject other inbound traffic. Browsers and mobile clients must use the same-origin wss://<host>:8080/rtc proxy.

The native C++ executable defaults to port 7880 for direct, insecure debugging. Keep that traffic on the XR AI host whenever possible. If a native client must connect directly from a trusted development network, restrict access to its source subnet. For example, with a 192.168.1.0/24 development network:

sudo ufw allow from 192.168.1.0/24 to any port 7880 proto tcp
sudo ufw reload

Apply the equivalent source restriction to the cloud security group. Do not expose port 7880 to the public Internet: it carries plaintext signaling, and a LiveKit bearer token authenticates a client but does not encrypt the transport.

Cloud VMs behind NAT#

The signaling proxy on port 8080 does not proxy WebRTC media. LiveKit still needs to advertise an ICE address that clients can reach on ports 7881 and 7882. On a cloud VM whose network interface has only a private address, enable STUN-based public-IP discovery in the sample’s device_io_hub.yaml:

lk_use_external_ip: true

LiveKit validates the discovered address with a self-ping before advertising it. If the provider’s NAT does not support that hairpin path, also skip the validation:

lk_use_external_ip: true
lk_skip_external_ip_validation: true

Skipping validation does not make a closed port reachable. Ensure the VM’s cloud firewall and host firewall allow 7881/TCP and 7882/UDP. Keep both options disabled for local and private-network deployments.

NAT also affects the TLS certificate: clients dial the VM’s public IP, which must be listed in the certificate’s SAN via web_server_extra_sans. Refer to TLS for the web client below.

RHEL, Fedora, or CentOS (firewall-cmd)#

sudo firewall-cmd --permanent --add-port=7881/tcp
sudo firewall-cmd --permanent --add-port=7882/udp
sudo firewall-cmd --permanent --add-port=8080/tcp
sudo firewall-cmd --permanent --add-port=48322/tcp
sudo firewall-cmd --reload

Live agent-event viewer#

The WebEventsAgent SDK and shipped samples default to http://127.0.0.1:8092. For access from another machine, keep the loopback binding and use an SSH tunnel:

ssh -L 8092:127.0.0.1:8092 user@xr-host

Then open http://127.0.0.1:8092 locally.

For direct access on a trusted private network, pass --expose-web-events to the lab-instrument or tea-making sample. This binds the viewer to 0.0.0.0:8092. Applications can configure the same behavior when registering their viewer with the runtime:

viewer = runtime.register(
    "web-events",
    WebEventsAgent(host="0.0.0.0", port=8092),
)

Restrict the firewall rule to the client subnet instead of opening the port to every source. For example, with ufw and a 192.168.1.0/24 development network:

sudo ufw allow from 192.168.1.0/24 to any port 8092 proto tcp
sudo ufw reload

Apply the equivalent source-restricted rule to the cloud security group when the host is behind a provider firewall. The viewer rejects unrecognized HTTP Host names to prevent DNS rebinding. Connect using a literal server address; an authenticated reverse proxy can instead rewrite Host to 127.0.0.1. The listener currently accepts IPv4 addresses only.

Warning

The live event viewer does not provide authentication or TLS, and its payloads can include transcripts and camera-derived text. Do not expose port 8092 to the public Internet. Use the loopback binding with an SSH tunnel, or put the viewer behind an authenticated TLS reverse proxy.

TLS for clients#

TLS is on by default — web_server_tls: true is the built-in default. The web server terminates HTTPS on web_server_port (8080 by default) and also exposes a same-origin wss://<host>:8080/rtc proxy that forwards LiveKit signaling to the internal plaintext port. Browsers and mobile clients use only this path. It is also the supported native C++ path when the executable runs with --secure --port 8080; the native executable’s port 7880 default is an insecure debugging exception.

On first run DeviceIOHub generates a stable development root CA and a server leaf signed by that root under ~/.local/share/xr-ai/:

  • root-ca.crt and root-ca.key are the stable trust anchor. Only the public certificate is available from /cert; the private key never leaves the hub.

  • web-server.crt and web-server.key are the CA-signed server leaf and its private key. The web server presents this leaf for HTTPS and WSS.

To use your own certificate, set cert_file and key_file in device_io_hub.yaml. Externally managed TLS continues to work unchanged; /cert returns 404 because DeviceIOHub does not own that certificate’s root.

The generated leaf covers localhost, the hostname, and automatically discovered local IPv4 addresses. When clients dial an address that discovery misses, or one that is not local (the public IP of a NAT’d cloud VM such as Brev, a forwarding proxy’s address, or a DNS name), list it in device_io_hub.yaml and the leaf is regenerated to include it on the next hub start:

web_server_extra_sans:
  - 203.0.113.7
  - hub.example.com

Changing these addresses never rotates root-ca.crt, so clients do not need to reinstall the root after a Brev public-IP change.

DeviceIOHub checks the generated certificates daily. It renews the server leaf 30 days before expiration and reloads it for new HTTPS and WSS connections without restarting the hub; the root CA remains unchanged. Existing connections can finish using the certificate negotiated when they connected.

If root-ca.crt or root-ca.key is missing, unreadable, mismatched, or within 30 days of expiration, DeviceIOHub replaces the root and server leaf and logs a warning. Previously enrolled clients reject the new chain. Reinstall the new root-ca.crt on every client using the platform-specific steps below; /cert serves the current root after the replacement.

To disable TLS for localhost-only dev where the certificate warning is noise, set web_server_tls: false. With TLS off, the same-origin proxy serves plain ws:// instead of wss://, and localhost is the only context where camera and mic permissions are granted without HTTPS.

To trust the development root CA so you stop seeing the warning:

  • Chrome or Edge: navigate to https://<host>:8080, click Advanced → Proceed to … (unsafe).

  • Firefox: click Advanced → Accept the Risk and Continue.

  • Android: tap Install hub certificate in the app’s Connection section (visible before the first connection). The app fetches the public root CA from https://<host>:<port>/cert and opens the system install dialog. After confirming, connect normally — the LiveKit SDK validates against the system + user CA store automatically.

  • iOS, iPadOS, and visionOS: tap Install hub certificate in the app’s Connection section. This opens Safari at https://<host>:<port>/cert. In Safari: tap Show Details → visit this website past the certificate warning → Download Configuration Profile → Allow → install via Settings → General → VPN & Device Management → enable Settings → General → About → Certificate Trust Settings → Enable Full Trust for the new certificate.

Warning

On iOS, this step is mandatory: the LiveKit Swift SDK’s URLSession does not expose a server-trust auth-challenge hook, and ATS does not bypass certificate-chain validation regardless of NSAllowsArbitraryLoads. Until the certificate is trusted at the OS level, the wss handshake fails.

Linux native certificate trust#

The native C++ client validates the hub through the Linux system CA bundle. Before connecting, ensure the address passed to --host appears in the server leaf’s subject alternative names. If the native client uses another IP address or DNS name, configure web_server_extra_sans and restart the hub to regenerate only the leaf and leaf key.

Copy the resulting ~/.local/share/xr-ai/root-ca.crt from the hub host to the native client host. On Ubuntu or Debian, install that copy and refresh the bundle:

sudo install -m 0644 /path/to/root-ca.crt \
  /usr/local/share/ca-certificates/xr-ai-hub.crt
sudo update-ca-certificates

Restart the native client after updating the bundle. Later SAN changes rotate only the server leaf and do not require another trust installation.

For production deployments on any platform, replace the auto-generated certificate with one from a public CA by setting cert_file and key_file in device_io_hub.yaml.