Development of SMS Reselling Platform (SMPP Based) -- 2

Project Overview

We are looking for an experienced developer/team to design and develop a **high-performance SMS Reselling Platform** based on **SMPP protocol**, capable of handling large-scale SMS traffic with high reliability, scalability, and security.

The platform will be built using **.NET (Core/Latest Version)** for RESTful API services, **RabbitMQ** for message queuing, and **Microsoft SQL Server (MSSQL)** as the primary database.

This system will allow us to operate as an SMS aggregator/reseller, connect with multiple upstream SMS providers via SMPP, and provide API access to downstream clients.


## Core Objectives

* Develop a scalable SMS gateway platform
* Integrate SMPP client connections with upstream providers
* Provide REST API for customers to send SMS
* Implement asynchronous message processing using RabbitMQ
* Real-time DLR (Delivery Report) handling
* Billing, routing, and reporting system
* High throughput and fault-tolerant architecture

## Technical Stack (Mandatory)

* **Backend:** .NET 8 / .NET Core (RESTful API)
* **Database:** Microsoft SQL Server (MSSQL)
* **Queue System:** RabbitMQ
* **Protocol:** SMPP (v3.4 or above)
* **Hosting:** Windows/Linux Server (Docker support preferred)

## Key Features Required

### 1. SMPP Integration

* Multiple SMPP bind (Transceiver/Transmitter/Receiver)
* Auto reconnect mechanism
* Enquire link handling
* Throughput control (TPS management)
* Delivery report (DLR) processing
* TON/NPI configuration
* Long SMS (UDH) support
* Unicode SMS support

### 2. RESTful API for Clients

* Authentication (API key / JWT based)
* Send single & bulk SMS
* Scheduled SMS
* Message status query
* DLR webhook callback
* Balance check API

### 3. Message Queue Architecture

* All outbound messages must be queued via RabbitMQ
* Retry mechanism for failed messages
* Dead-letter queue support
* Load balancing support

### 4. Billing & Credit Management

* Prepaid credit system
* Rate management per route
* Automatic credit deduction
* Multi-route pricing
* Credit alerts

### 5. Routing Engine

* Route prioritization
* Failover routing
* Sender ID masking support
* Country/operator-based routing

### 6. Admin Panel (Web-Based)

* Dashboard (Traffic, TPS, Revenue)
* Client management
* SMPP account management
* Route management
* Real-time logs
* Reporting (Daily/Monthly)
* Export to Excel/CSV

### 7. Reporting & Analytics

* Message logs (searchable & filterable)
* Delivery rate statistics
* Revenue reports
* Client usage summary

### 8. Performance Requirements

* Handle minimum 50–200 TPS (scalable architecture preferred)
* Optimized database design
* Non-blocking async processing
* Proper logging & monitoring

## Security Requirements
*SPAM FILTERING
* Role-based access control
* API rate limiting
* IP whitelisting
* Encrypted configuration storage
* Secure SMPP credential management

## Deliverables

* Complete source code
* Database schema & scripts
* API documentation (Swagger)
* SMPP integration documentation
* Deployment guide
* 30 days post-deployment support
* Optional: Dockerized deployment

## Preferred Developer Qualifications

* Strong experience with SMPP protocol
* Experience building SMS gateway or telecom platforms
* Strong knowledge of .NET asynchronous programming
* Experience with RabbitMQ message architecture
* MSSQL performance tuning experience
* Knowledge of telecom billing logic

## Project Timeline

Estimated duration: **2-3 weeks**

Proposal Requirements
Please include in your proposal:

* Previous SMS/SMPP related project experience
* Architecture approach
* Expected TPS capability
* Estimated timeline
* Support & maintenance terms