PTT Bridge
Bridge your radios to everything
For two-way radio dealers running WalkieFleet PoC. Connect your talkgroups to IP phones, PBXs, dispatch consoles, RoIP gateways, and overhead paging, with real-time two-way audio, automatic transcoding, and end-to-end encryption. Install it on a compact appliance at your site or as a virtual machine in your on-prem environment, and manage it all from a browser.
Deployment
Built for on-site deployment
PTT Bridge runs on our compact on-site appliance. If you would rather use hardware you already run, the same software installs as a virtual machine in your on-prem environment.
On-site appliance
Our standard deployment: a compact, fanless appliance installed at your site. Silent, with no moving parts, and available with an optional on-board 4G LTE card for cellular connectivity.
On-prem virtual machine
Prefer to use infrastructure you already own? Run the same software as a virtual machine in your on-prem virtual environment.
Hardware
The on-site appliance
Our standard on-site deployment runs on a compact, fanless appliance with a finned heat-sink case. Silent, with no moving parts, and available with an optional on-board 4G LTE card.
Connection panel
Dimensions
Ports
- 2 × Ethernet (RJ-45)
- 1 × HDMI
- 1 × VGA
- 12 V DC power input
- Optional on-board 4G LTE card
Physical
- Dimensions
- 5.7 × 5.0 × 1.5 in (145 × 127 × 38 mm)
- Power
- 12 V DC
- Operating temp
- 14 to 140 °F (-10 to +60 °C)
- Storage temp
- -4 to 158 °F (-20 to +70 °C)
External SIP access uses ports 5060 (UDP/TCP) and 5061 (TLS).
The Core
Bridge your radios to everything
Four connection types cover phones, PBXs, dispatch consoles, RoIP gateways, recorders, and overhead paging. Pair any two into a bridge.
WalkieFleet PoC
Logs in as a virtual radio, joins a talkgroup, and passes PTT audio, presence, and GPS just like a physical handset.
Talkgroups auto-discovered
SIP Endpoint
Full SIP signaling to an IP phone, PBX trunk, paging adapter, recorder, or gateway. It registers to your proxy, dials a peer, or serves its own registrar.
Supports JPS RSP-Z2, Cubic Vocality, SNOM PA1
Static RTP / RoIP
Bare RTP peer with no signaling. Connect radio-over-IP, RoIP gateways, and Critical Communications Recorders by host and port.
Any standard RTP interface
Line-Out to Paging
Plays talkgroup audio out to a paging amplifier or speaker, with call-announce tones and feedback-safe playback.
One way to the PA. Single beep, two-tone, chimes, or triple beep.
Mix and match into a bridge
Pair any two connections. Audio flows both ways, except to paging and recorders, which are one way.
Key Capabilities
What the bridge gives you on every connection.
Real-time two-way audio
On a two-way pairing, each side of the bridge hears the other, live.
Automatic codec translation
G.711 and GSM-FR with sample-rate matching between both sides.
Built-in SIP registrar
Phones register directly over UDP, TCP, and TLS.
End-to-end SRTP encryption
AES-CM-128 media encryption on every leg.
Browser-managed, no CLI
Configure and monitor from anywhere. No command line.
Secure remote access
Tailscale or self-hosted Headscale overlay VPN.
Detailed Specifications
The full capability set behind the bridge: media, management, signaling, secure access, and operations.
Media, Codecs & Call Quality
- Full transcoding: G.711 A-law (PCMA), µ-law (PCMU), and GSM-FR
- Automatic sample-rate conversion (8, 16, 24, and 48 kHz) between both sides
- Per-connection codec priority ordering
- SRTP media encryption (AES-CM-128 / HMAC-SHA1-80)
- Adaptive jitter buffer with 7 levels (about 20 to 400 ms) to balance latency against resilience
- Automatic NAT traversal with multiple keepalive styles
- SIP session timers (RFC 4028) to clear half-dead calls
- Anti-injection RTP source-locking with clean phantom-call recovery
- Voice-activity PTT gating, so plain SIP phones key the radio automatically
- Auto-dial modes: Always (persistent), On-Transmit (per PTT), or Never (inbound)
Management & Access Control
- Web GUI console to configure and monitor from a browser, with no CLI for day-to-day operation
- Live dashboard with status tiles for connections, bridges, radios, GPS, and VPN, plus host and database health
- Role-Based Access Control with Users, reusable Roles, and Groups for fine-grained permissions
- Authentication with failed-login throttling and lockout, enforced server-side on every action
- TLS certificate management: Let's Encrypt issuance and auto-renewal, self-signed generation, custom import, and one-click hot-reload deploy
Built-in SIP Registrar
- Phones, softphones, and dispatch consoles register directly over UDP, TCP, and TLS (SIPS, port 5061)
- Digest authentication (MD5 or SHA-256)
- Failed-authentication lockout
- IP and CIDR source allowlist
- Per-endpoint or global SRTP policy (disabled, optional, or required)
- Optional "require TLS for credentials" hardening
- Live Registrations view with NAT-aware contact tracking
- Disabled by default, so nothing listens until you enable it
Secure Remote Access (VPN)
- Tailscale overlay VPN (SaaS) over WireGuard for a private, encrypted path with no public exposure that survives reboots
- Headscale overlay VPN (self-hosted) using the same client and your own coordination server, friendly to air-gapped and provider-neutral setups
- Subnet routing to reach private resources by internal IP
- DNS-safe by design, so VPN DNS rewriting stays off and never interferes with SIP hostname resolution
- Live peer-path visibility that shows Direct against Relayed, with a relay-latency warning
Operations & Assurance
- Unified, searchable event log with about 30 days of history, scoped by group
- Live, level-selectable bridge logs for deep troubleshooting
- Least-privilege security model, with secrets scrubbed from logs and kept out of the database
- Resilient by design, with supervised services that auto-restart and configuration that converges automatically
See the bridge running in your setup
We will walk you through a live PTT Bridge, show how it deploys on a site appliance or in your on-prem virtual environment, and scope it to your talkgroups and endpoints.