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go-m3ua

Simple M3UA protocol implementation in the Go programming language.

CI status golangci-lint Go Reference GitHub

Quickstart

Installation

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

This project follows the Release Policy of Go.

*Non-Linux machines are 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

ClassMessageSupportedNotes
TransferPayload Data Message (DATA)YesRFC4666#3.3
SSNMDestination Unavailable (DUNA)YesRFC4666#3.4
Destination Available (DAVA)Yes
Destination State Audit (DAUD)Yes
Signalling Congestion (SCON)Yes
Destination User Part Unavailable (DUPU)Yes
Destination Restricted (DRST)Yes
ASPSMASP UpYesRFC4666#3.5
ASP Up Acknowledgement (ASP Up Ack)Yes
ASP DownYes
ASP Down Acknowledgement (ASP Down Ack)Yes
Heartbeat (BEAT)Yes
Heartbeat Acknowledgement (BEAT Ack)Yes
RKMRegistration Request (REG REQ)RFC4666#3.6
Registration Response (REG RSP)
Deregistration Request (DEREG REQ)
Deregistration Response (DEREG RSP)
ASPTMASP ActiveYesRFC4666#3.7
ASP Active Acknowledgement (ASP Active Ack)Yes
ASP InactiveYes
ASP Inactive Acknowledgement (ASP Inactive Ack)Yes
MGMTErrorYesRFC4666#3.8
NotifyYes

Parameters

TypeParametersSupportedNotes
CommonINFO StringYes
Routing ContextYes
Diagnostic InformationYes
Heartbeat DataYes
Traffic Mode TypeYes
Error CodeYes
StatusYes
ASP IdentifierYes
M3UA-specificNetwork AppearanceYes
User/CauseYes
Congestion IndicationsYes
Concerned DestinationYes
Routing KeyYes
Registration ResultYes
Deregistration ResultYes
Local Routing Key IdentifierYes
Destination Point CodeYes
Service IndicatorsYes
Originating Point Code ListYes
Protocol DataYes
Registration StatusYes
Deregistration StatusYes

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)

LICENSE

MIT