Fields as Parameters

SMPP PDUs and REST API requests both pass data using structured parameters, but they do so differently.

• RESTful APIs use URL queries, HTTP headers, or JSON fields to transmit parameters.
• SMPP PDUs embed data within mandatory fields (always required) and optional fields (TLVs – Tag-Length-Value pairs) for additional functionality.

Here is a simple example of sending an SMS.
REST API Request (JSON)
A simple HTTP POST request to send an SMS via a REST API might look like this:
POST /messages/send HTTP/1.1
Host: sms.api.com
Content-Type: application/json
{
  "destination_number": "+1234567890",
  "message": "Hello",
  "priority": "high",
  "validity_period": "24h",
  "delivery_receipt": "requested"
}

SMPP submit_sm PDU
The same request would be structured as a binary PDU in SMPP:
┌─────────────────────────────────┐
│ Command ID: 0x00000004          │  → submit_sm
│ Sequence Number: 1001           │
├─────────────────────────────────┤
│ destination_addr: "+1234567890" │ (Mandatory)
│ short_message: "Hello"          │ (Mandatory)
│ priority_flag: 1                │ (Optional TLV)
│ validity_period: "24h"          │ (Optional TLV)
│ registered_delivery: 1 (DLR)    │ (Optional)
└─────────────────────────────────┘