VoIP Server¶

The GVA VoIP Server (gva-voip-server) is a SIP registrar and proxy server designed for military vehicle communications. It manages user registration, call routing, and provides centralised logging of call activity.

Overview¶

sequenceDiagram participant C1 as Client 1 participant SRV as VoIP Server participant C2 as Client 2 Note over C1,SRV: Registration C1->>SRV: REGISTER SRV->>C1: 200 OK Note over C2,SRV: Registration C2->>SRV: REGISTER SRV->>C2: 200 OK Note over C1,C2: Call Setup C1->>SRV: INVITE (to C2) SRV->>C2: INVITE C2->>SRV: 180 Ringing SRV->>C1: 180 Ringing C2->>SRV: 200 OK (SDP) SRV->>C1: 200 OK (SDP) C1->>SRV: ACK SRV->>C2: ACK Note over C1,C2: RTP Media (Direct) C1<-->C2: Audio Stream Note over C1,C2: Call Teardown C1->>SRV: BYE SRV->>C2: BYE C2->>SRV: 200 OK SRV->>C1: 200 OK

Features¶

SIP Registration¶

User registration with configurable expiry
Multiple registrations per user (forking)
Registration state published to DDS

Call Routing¶

Direct call routing between registered users
Call forwarding support
Busy/unavailable handling

Call Detail Records (CDR)¶

The server maintains detailed logs of all calls:

2026-04-13 16:30:45 | operator1 -> operator2 | CONNECTED | 00:05:23 | G.729
2026-04-13 16:36:08 | operator2 -> agent.ai  | COMPLETED | 00:02:15 | MELPe

Quality of Service¶

DSCP EF (46) marking for voice packets
RTP packet prioritisation
Jitter buffer recommendations

Command Line Options¶

gva-voip-server [options]

Options:
  -h, --help               Show help message
  -v, --version            Show version
  -a, --address=<addr>     Bind address (default: 0.0.0.0)
  -p, --port=<port>        SIP listen port (default: 5060)
  -f, --groups-file=<path> Load conference groups from JSON file
  -g, --group=<name>       Add a conference group (repeatable)
  -w, --wideband           Use wideband codec profile (RFC 8817)

Examples¶

# Start server with groups file
gva-voip-server -f /etc/gva-voip-server/groups.json

# Custom address and individual groups
gva-voip-server --address=192.168.1.1 -g command -g alpha -g bravo

Configuration¶

Default Ports¶

Service	Port	Protocol
SIP Signalling	5060	UDP/TCP
RTP Media	10000-10100	UDP

Supported Codecs¶

The server supports codec negotiation via SDP. Clients advertise their supported codecs and the server facilitates negotiation:

Payload Type	Codec	Clock Rate
0	PCMU (G.711 μ-law)	8000
8	PCMA (G.711 A-law)	8000
18	G.729	8000
96	MELPe 2400	8000
97	TSVCIS (STANAG 4591)	8000
111	Opus	48000

DDS Integration¶

The VoIP Server publishes registration and call state to the DDS domain:

Topics Published¶

P_VoIP_Registration - User registration events
P_VoIP_CallState - Active call information
P_VoIP_Statistics - Server statistics

Topics Subscribed¶

C_VoIP_Config - Dynamic configuration updates

Example Usage¶

Starting the Server¶

# Basic startup
./build/bin/gva-voip-server --domain=0

# Production mode with CDR logging
./build/bin/gva-voip-server \
    --domain=0 \
    --dscp-ef \
    --cdr-file=/var/log/gva/voip-cdr.log \
    --headless

Testing Registration¶

# Start server
./build/bin/gva-voip-server --domain=0 &

# Register clients
./build/bin/gva-voip-client --user=alice --server=127.0.0.1 &
./build/bin/gva-voip-client --user=bob --server=127.0.0.1 &

# Alice can now call bob@127.0.0.1

Troubleshooting¶

Common Issues¶

Port already in use:

Error: Failed to bind to port 5060

Another SIP server or instance is running. Either stop it or use a different port:

./build/bin/gva-voip-server --port=5061

Registration timeout: Ensure firewall allows UDP traffic on ports 5060 and 10000-10100.

No audio: Check that RTP ports are not blocked and clients can reach each other directly.