examples

Diameter Gateway Examples

Collection of examples demonstrating various aspects of the Diameter Gateway client.

Examples by Complexity

1. Simple Pool (simple_pool/)

Complexity: ⭐ Beginner

Minimal example showing:

• Connection pool creation
• State monitoring
• Basic statistics

Best for: Understanding the basics

cd simple_pool
go run main.go

2. S13 Client (s13_client/)

Complexity: ⭐⭐⭐ Production

Complete S13 gateway implementation with:

• Full connection pool setup
• S13 message handling (ECR/ECA)
• Statistics reporting
• Graceful shutdown
• Signal handling

Best for: Production deployment reference

cd s13_client
go build -o s13-gateway main.go
./s13-gateway

3. Basic (basic/)

Complexity: ⭐ Legacy

Legacy examples predating the client package:

• Simple CER/CEA handshake
• Low-level protocol operations

Best for: Understanding protocol fundamentals

cd basic
go run simple_cer_cea.go

Quick Start

Running Without DRA Server

All examples can run without a real DRA server to demonstrate:

• Connection retry behavior
• Reconnection logic
• Error handling
• State management

Running With DRA Server

1. Update the configuration in each example:

   config.Host = "your-dra-host.example.com"
   config.Port = 3868
   config.OriginHost = "your-gateway.example.com"
   config.OriginRealm = "your-realm.com"

2. Run the example:

   go run main.go

Example Progression

Recommended learning path:

simple_pool     →     s13_client     →     Production
(Learn basics)     (Learn features)     (Deploy)

Features Demonstrated

Feature	simple_pool	s13_client	basic
Connection Pool	✓	✓	✗
CER/CEA	✓	✓	✓
DWR/DWA	✓	✓	✗
Auto-reconnect	✓	✓	✗
Load Balancing	✓	✓	✗
S13 Messages	✗	✓	✗
Statistics	✓	✓	✗
Graceful Shutdown	✓	✓	✗
Signal Handling	✗	✓	✗

Common Configuration

All examples use similar configuration:

config := client.DefaultConfig()
config.Host = "127.0.0.1"              // DRA address
config.Port = 3868                     // Diameter port
config.OriginHost = "gateway.example.com"
config.OriginRealm = "example.com"
config.ConnectionCount = 5             // Connection pool size
config.DWRInterval = 30 * time.Second  // Heartbeat interval

Testing Tips

1. Test Connection Handling

# Start example
go run simple_pool/main.go

# While running, stop/start your DRA to see reconnection

2. Test Load Balancing

# Send multiple messages and watch them distribute
# across connections (see s13_client example)

3. Test Graceful Shutdown

# Press Ctrl+C and observe clean shutdown
go run s13_client/main.go
^C

Building Examples

Build All

# From examples directory
go build -o bin/simple-pool simple_pool/main.go
go build -o bin/s13-gateway s13_client/main.go

Build with Optimizations

go build -ldflags="-s -w" -o s13-gateway s13_client/main.go

Troubleshooting

"connection refused"

• DRA server not running
• Wrong host/port
• Firewall blocking

Solution: Examples work without DRA to show retry behavior

"no active connections"

• All connections failed to establish
• DRA rejecting connections
• Network issues

Solution: Check DRA logs and network connectivity

High CPU usage

• Too many reconnection attempts
• Increase ReconnectInterval

Solution: Adjust backoff settings in config

Resources

• Client Package Documentation
• Design Document
• Implementation Summary
• RFC 6733: Diameter Base Protocol
• 3GPP TS 29.272: S13 Interface

Contributing

To add a new example:

1. Create a new directory: examples/my_example/
2. Add main.go and README.md
3. Update this main README
4. Ensure it builds and runs
5. Document what it demonstrates

License

Part of the Diameter Gateway project.