m3ua

go-m3ua

Simple M3UA protocol implementation in pure Golang.

Quickstart

Installation

Just run go mod tidy in your project's directory to collect the required packages automatically.

go mod tidy

This project follows the Release Policy of Go.

*Non-Linux machine is NOT supported, as this package relies much on github.com/ishidawataru/sctp.

Trying Examples

Working examples are available in examples directory. Just executing the following commands, you can see the client and server setting up M3UA connection.

# Run Server first
cd examples/server
go run m3ua-server.go

// Run Client then
cd examples/client
go run m3ua-client.go

There is also an example for Point Code format conversion, which works like this;

$ ./pc-conv -raw 1234 -variant 3-8-3
2023/04/05 06:07:08 PC successfully converted.
        Raw: 1234, Formatted: 0-154-2, Variant: 3-8-3
$ 
$ ./pc-conv -str 1-234-5 -variant 4-3-7
2023/04/05 06:07:08 PC successfully converted.
        Raw: 29957, Formatted: 1-234-5, Variant: 4-3-7

For Developers

The API design is kept as similar as possible to other protocols in standard net package. To establish M3UA connection as client/server, you can use Dial() and Listen()/Accept() without caring about the underlying SCTP association, as go-m3ua handles it together with M3UA ASPSM & ASPTM procedures.

Here is an example to develop your own M3UA client using go-m3ua.

First, you need to create *Config used to setup/maintain M3UA connection.

config := m3ua.NewClientConfig(
    &m3ua.HeartbeatInfo{
        Enabled:  true,
        Interval: time.Duration(3 * time.Second),
        Timer:    time.Duration(10 * time.Second),
    },
    0x11111111, // OriginatingPointCode
    0x22222222, // DestinationPointCode
    1,          // AspIdentifier
    params.TrafficModeLoadshare, // TrafficModeType
    0,                     // NetworkAppearance
    0,                     // CorrelationID
    []uint32{1, 2},        // RoutingContexts
    params.ServiceIndSCCP, // ServiceIndicator
    0, // NetworkIndicator
    0, // MessagePriority
    1, // SignalingLinkSelection
)
// set nil on unnecessary paramters.
config.CorrelationID = nil

Then, prepare network addresses and context and try to connect with Dial().

// setup SCTP peer on the specified IPs and Port.
raddr, err := sctp.ResolveSCTPAddr("sctp", SERVER_IPS)
if err != nil {
    log.Fatal(err)
}

ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()

conn, err := m3ua.Dial(ctx, "m3ua", nil, raddr, config)
if err != nil {
    log.Fatalf("Failed to dial M3UA: %s", err)
}
defer conn.Close()

Now you can Read() / Write() data from/to the remote endpoint.

if _, err := conn.Write(d); err != nil {
    log.Fatalf("Failed to write M3UA data: %s", err)
}
log.Printf("Successfully sent M3UA data: %x", d)

buf := make([]byte, 1500)
n, err := conn.Read(buf)
if err != nil {
    log.Fatal(err)
}

log.Printf("Successfully read M3UA data: %x", buf[:n])

See example/server directory for server example.

Supported Features

Messages

Parameters

Disclaimer

This is still experimental project. In some part, the behavior is not fully compliant with RFC, and some of the features are not even implemented yet.

Also note that some exported APIs may be changed without any notice before first release (v1.0.0).

Author

Yoshiyuki Kurauchi (Website / Twitter)

LICENSE

MIT