SMPP connection guide

Getting access

1. In the portal, go to Settings and request SMPP access.
2. Once enabled, your system_id appears there. The bind password is your mbs_ API token: the same one you create under API Tokens in the portal sidebar (it needs the message-send scope).
3. Whitelist of your source IPs may be requested for production binds.

Connection parameters

Message encoding

• data_coding=0: GSM-7 default alphabet (160 chars/segment).
• data_coding=8: UCS-2 for Unicode (70 chars/segment).
• Long messages: use UDH concatenation (esm_class=0x40) or message_payload; both are supported.

Delivery receipts

Set registered_delivery=1 on submit_sm; DLRs arrive as deliver_sm with the standard receipt text format:

id:7c31a2f4 sub:001 dlvrd:001 submit date:2607111015 done date:2607111016 stat:DELIVRD err:000 text:…

Bind and send: code examples

A transceiver bind that submits one message and listens for delivery receipts, in the most common SMPP client stacks. Swap in the host, port and credentials from your portal Settings page.

// go get github.com/linxGnu/gosmpp
package main

import (
	"fmt"
	"log"
	"os"
	"time"

	"github.com/linxGnu/gosmpp"
	"github.com/linxGnu/gosmpp/data"
	"github.com/linxGnu/gosmpp/pdu"
)

func main() {
	auth := gosmpp.Auth{
		SMSC:       "smpp.mobilesasa.com:2775",
		SystemID:   "your_system_id",
		Password:   os.Getenv("MOBILESASA_TOKEN"), // your mbs_ API token
		SystemType: "",
	}

	trans, err := gosmpp.NewSession(
		gosmpp.TRXConnector(gosmpp.NonTLSDialer, auth),
		gosmpp.Settings{
			EnquireLink: 30 * time.Second, // keepalive
			OnPDU: func(p pdu.PDU, _ bool) {
				if dsm, ok := p.(*pdu.DeliverSM); ok {
					msg, _ := dsm.Message.GetMessage()
					fmt.Println("DLR:", msg) // id:… stat:DELIVRD …
				}
			},
			OnRebindingError: func(err error) { log.Println("rebind:", err) },
		},
		5*time.Second,
	)
	if err != nil {
		log.Fatal(err)
	}
	defer trans.Close()

	sm := pdu.NewSubmitSM().(*pdu.SubmitSM)
	sm.SourceAddr = pdu.NewAddressWithAddr("DUKAPAY")
	sm.SourceAddr.SetTon(5) // alphanumeric
	sm.SourceAddr.SetNpi(0)
	sm.DestAddr = pdu.NewAddressWithAddr("254712345678")
	sm.DestAddr.SetTon(1) // international
	sm.DestAddr.SetNpi(1)
	sm.Message, _ = pdu.NewShortMessageWithEncoding(
		"Your OTP is 482913", data.GSM7BIT)
	sm.RegisteredDelivery = 1 // request DLRs

	if err := trans.Transceiver().Submit(sm); err != nil {
		log.Fatal(err)
	}

	select {} // keep the bind alive
}

Response codes

Every submit_sm_resp carries a standard SMPP v3.4command_status. Zero means accepted and themessage_id is the tracking id you will see in delivery receipts. These are the ones we send and what each means here:

Keeping the bind healthy

• Send enquire_link every 30 seconds; treat two missed responses as a dead bind and reconnect with backoff.
• Respect the throughput agreed for your account; submit windows above it are throttled with ESME_RTHROTTLED: back off, don't hammer.
• Reconnect storms hurt everyone: cap reconnection attempts at one per 5 seconds with jitter.