Connecting

Connection URLs

The quickest way to configure a client is a connection URL:

new SmppClient({ url: "smpp://systemId:password@smsc.example.com:2775" });
new SmppClient({ url: "ssmpp://smsc.example.com" }); // TLS, port defaults to 3550
new SmppClient("smpp://localhost"); // a bare string works too

• smpp:// — plain TCP, default port 2775
• ssmpp:// — TLS, default port 3550
• user:pass in the URL become the default systemId/password for binds
• URL-encoded characters are decoded (sec%40ret → sec@ret)

Discrete options override URL parts:

new SmppClient({
  url: "smpp://user:pw@example.com",
  port: 12775,        // wins over the URL
  systemId: "other",  // wins over the URL user
});

TLS

Pass tls: true or full node:tls connect options:

new SmppClient({
  host: "smsc.example.com",
  port: 3550,
  tls: { ca: [fs.readFileSync("smsc-ca.pem")] },
});

Certificates are verified by default — unlike the original node-smpp, which silently disabled verification. For self-signed test peers, opt out explicitly:

tls: { rejectUnauthorized: false }

Connect and teardown

await client.connect();   // resolves when the transport is ready for a bind
// ...
await client.unbind();    // polite unbind handshake
await client.close();     // graceful FIN; resolves once the socket closed
client.destroy();         // immediate teardown

connect() rejects with SmppTimeoutError after connectTimeoutMs (default 30 s) or with the underlying socket error (ECONNREFUSED, ENOTFOUND, …).

close() and destroy() are user-initiated: they never trigger the automatic reconnect. Only unexpected connection loss does — see Reliability.

Connection state

client.connected;    // transport up?
client.sessionState; // "OPEN" | "BOUND_TX" | "BOUND_RX" | "BOUND_TRX" | "UNBOUND" | "CLOSED"

Every request also fails fast with SmppClosedError when the client is not connected (unless a reconnect is in progress — then it waits).