
The best C# VoIP SDK for Android
This is the best tool you can use to develop Voice over IP (VoIP) applications in C#.Net for Android Mobile phones. You can write softphones, call center clients and many other innovative solutions. The SDK offers the VoIP tools needed including a full implementation of the SIP, SDP and RTP protocols and easy access to the audio and video hardware of your phone. You can use Visual Studio with the built in Xamarin libraries and you can enjoy the benefits of Ozeki SDK that was fully implemented in C#. Ozeki VoIP SIP SDK for Android is compatible with Ozeki VoIP SIP SDK for Windows. This means, that your code is portable between the two products. If you have not already done so, download Ozeki VoIP SIP SDK for Android now, and start to build your first mobile VoIP solution.
VoIP calls
Call center clients
SIP messaging
Audio access
Long term support
Ozeki has been providing VoIP products since year 2005. Ozeki VoIP SIP SDK for Android is our latest and most advanced VoIP SDK product. We are dedicated to providing long term support and develpment for this product. Ozeki VoIP SIP SDK for Android will be supported for 10 years until 2033.
Getting started

Download
Download a trial version and test the full functionality for two weeks free of charge.
Screenshots
Check out the graphical user interface. You will see, that it is very easy to use and straightforward.
Quick start guide
The essential steps to send your first SMS. This guide helps you get started and can give you an idea on how things work.
How to buy
Get information about pricing, delivery terms, and support. Get in touch with us if you have any questions.
Purchase the source code
To make development more efficient, and to have full control over your code, purchase the full source code.How to connect your SMS Gateway to the mobile network?
To connect your SMS gateway to the mobile network you have various options. You can connect wirelessly the same way as mobile phones connect. You can connect to the SMSC of a mobile network operator over the Internet using the SMPP, UCP or CIMD2 protocol or you can use an on-line http sms service. In either case it is a good practice to use multiple connections to the mobile network for fault tolerance, load balancing, least cost routing and backup routing purposes. A common practice is to setup an IP sms connection (e.g. SMPP client connection) for everyday high performance messaging. After this connection is working, it is a good idea to setup a wireless link as backup. You can setup a wireless link using an SMS modem pool. These to connections will make sure your system operates even if the primary SMS service fails.
How to connect your SMS gateway to the mobile network wirelessly
To connect your SMS gateway to the mobile network wirelessly, you will send sms using a GSM modem, or you will send sms using a GSM modem pool or you will use an Android Mobile phone.
In either case you need SIM cards purchased from a local mobile network operator, and the phone numbers you can use as SMS Sender ID will be the phone numbers assigned to the SIM cards by the network operator. The advantage to using a wireless connection is that it is easy to setup, and often you can send and receive SMS messages free of charge over wireless links. (In fact many SMS service providers run a business of purchasing SMS modem pools with SIM cards and they sell the SMS messages and phone numbers to their clients over the Internet by providing an HTTP sms service.)
How to connect your SMS gateway to a mobile network operator
To send large volumes of SMS messages, a direct connection to the Short Message Service Center (SMSC) of a mobile network operator, or to a high capacity on-line SMS service is a good option. Mobile network operators and top SMS providers offer SMPP client connection or other heavy-duty SMS protocols, such as the UCP sms protocol, the CIMD2 sms protocol or the OZX sms protocol. In most cases you can connect to these providers through a secure SSL link. You may check out the how to create a secure smpp client connection guide on getting more information about this connection option.
How to connect your SMS gateway to an HTTP SMS service provider
The third option to connect your system to the mobile network is to connect to an HTTP SMS service provider. Although the HTTP protocol is not the most efficient option to send and receive SMS messages, because it puts a large data overhead on each SMS, and it does not support SMS delivery reports and inbound SMS messages properly, it is still used by many businesses. The primary reason for this is that an HTTP SMS connection can be setup very effortlessly.
To connect your system to an HTTP SMS service, you need to sign up to the service on their website, and you need to enter the account details they provide into Ozeki SMS Gateway. A list of supported SMS service providers can be found in our On-line SMS service poviders page. You will find step by step instructions for each provider on how to connect to their service.
Installation options
You may install your SMS gateway in your own server room to a physical or on a virtual server. A physical PC gives the best performance, a virtual pc can be great for system management and easy backups. All major virtualization platforms are supported (Linux Kvm, Oracle, VmWare, Microsoft Hyper-V, etc). As the host OS, you can install the SMS gateway on Windows or you may setup the SMS gateway on Linux.
Install your SMS gateway into the Cloud if you don't wish to operate a system on premises. Ozeki SMS Gateway supports installation into Amazon AWS, installation into Microsoft Azure, Google Cloud, Rackspace, Sigmanet, MHosting and many other cloud providers. This option requires a VPS service, that offers Windows or Linux servers.
For smaller operations, you may even install Ozeki SMS Gateway on an Android mobile phone, which gives you instant connection to the mobile network.
If you are into IoT sensors and hardware, you may choose to install Ozeki SMS Gateway on a Raspberry Pi. This gives you direct access to sensors and actuators attached to your embedded system. IoT Ozeki installations often communicate with a centeral Ozeki Gateway installed into the cloud.
How to provide SMS service with your SMS gateway
Once your SMS gateway is connected to your mobile networks you can create user accounts to provide SMS service to your business applications, to your office users or to your customers over the Internet. If you wish you can even become an SMS service provider.
Your SMS business applications will connect to your SMS gateway through one of the SMS APIs provided by the SMS gateway. They can send SMS through HTTP requests, through a database or by simply creating a text file in certain directory.
Office users will use the HTTP user interface of the SMS gateway from a webbrowser, or they will use an E-mail to SMS configuration or send sms from Excel.
If you want to offer SMS service to your cusotmers or to remote offices you can configure the built in SMPP server of Ozeki SMS Gatewy. Yes, Ozeki SMS Gateway can offer the same SMS service, that is offered by Mobile Network Operators. It has built in very powerful SMPP server.
Setup a high performance SMPP server
Ozeki 10 SMS gateway is the best software if you wish to provide SMS services for your customers, office users or business applications. If you are interested in setting up a robust system, you will be thriled once you experience the outstanding performance of the built in SMPP server. But don't take our word for it. Setup a test system free of charge in your own network, and push one million messages through it in real time! You will experience first hand the performance, and you will know that this is the best SMS gateway software out there. You will see, that the system is capable of delivering up to 1000 SMS messages per second and can do this over a sustained period of time.
If you wish to provide SMS service to your customers, office users or business applications, you will also like our client software offerings. Client software such as the Ozeki SMS Client, the Excel client or the Ozeki C# SMS api dll can be distributed without any limitations free of charge to your users. Your software developers will like the powerful HTTP SMS API. System administrators will be satisfied with the SMS routing capabilites and the high performance SQL reporting. We are proud of our SQL reporting implementation because we know that it will not lose any messages, even if your reporting database server goes offline temporarily. If the database is inaccessible, the messages will be temporarily saved into a text file, and will be pushed to the database once it comes back again.
Your users deserve outstanding relibility and performance, and Ozeki 10 SMS Gateway is here to deliver just that. Check out the information below to find out more.
Use advanced SMS routing
Ozeki SMS gateway has a world class SMS routing engine. This routing engine allows you to forward SMS mesages from one user or mobile network connection to another based on conditions you define. There are a large number of conditions, such as phone number prefix, message text matching, service period or time of day. In addition to routing by pattern matching, the SMS routing engine also allows you to modify the SMS text messages on the fly. You can replace the phone numbers, change the message text, append a note to the end of the messages. Find out more about SMS routing in the SMS routing basics guide.
Email to SMS for Exchange and Outlook
Office users in 2023 use Microsoft Office 365 whether they work from home, from a remote location or from your Office desktops. This means that they are hooked up to Microsoft Exchange that runs in the Azure cloud or in their on premises data center. Ozeki 10 SMS gateway can be easily configure to provide Email to SMS for Exchange.
Many Office users use Outlook, Windows mail, and some use Thunderbird as their primary email client. Ozeki SMS Gateway can be used to create email to sms and sms to email forwarding for these clients. You can find a standalone gide that explains how you can send sms from Windows Mail and how you can send sms from Mozilla Thunderbird.
Email to SMS for Linux based e-mail servers
In addition to Office 365 / Exchange support Ozeki SMS gateway offers standard email to sms and sms to email forwarding for other popular Email systems, such as Postfix, Sendmail, etc.... These standard e-mail systems use the SMTP, POP3 and IMAP protocols. Ozeki offers a secure impelmentation for all of these protocols. You can read more about these options by following the links bellow.
Easy to use GUI
The Ozeki SMS gateway user interface is very easy to use. It can be accessed from a webbrowser. (The web browser is served by the built in webserver of the SMS Gateway software). When you open the home page of the SMS gateway, you will see 4 panels as shown on the figure below. The left panel contains the installed mobile network connections. The middle two panels contain routing rules. The right panel contains the list of users and applications.
The first task you will do after installing Ozeki 10 SMS gateway, is setting up a connection to the mobile network. Next you will likely create user accounts or you will create an API access for software developers. Finally you will setup reporting to keep track of costs and to control the user activity in your service. The following pages provide useful information to complete these tasks:
Connect your system to the mobile networkHow to connect to SMPP SMS services
How to connect to UCP/EMI SMS services
How to connect to CIMD2 SMS services
How to connect to HTTP SMS services
How to use a mobile phone attached to the PC to connect to the mobile network
How to connect your system to multiple mobile networks
Provide SMS service
How to setup SMPP user accounts, so your users can connect to your system
Setup the HTTP API for developers who wish to send/receive SMS from apps
Learn about least cost routing based on phone number prefix
Find out how you can assign custom Sender IDs to your customers
Billing and reporting
Learn how to use the reporting database to support billing
How to find a single message and how to view it's history
Send SMS from applications
The best way to build a business is to rely on software instead of human work. Your automated software solutions will work precisely and reliable 24/7. Check out the following options offered for software developers by Ozeki 10 SMS Gateway. Developers can use these APIs to integrate SMS functionality into your applications, to make day-to-day operations more efficient.
SMS APIs for developers
Send SMS using HTTP
PHP SMS API
C# SMS API
VB.NET SMS API
Send SMS from a database
Many companies use relational database systems to store their data and their systems communicate with the databases using SQL. Ozeki 10 SMS gateway offers an easy way to create SMS functionality if you use a database. All you have to do is setup two database tables: one for sending SMS and another for receiving SMS, and let Ozeki pick up the SMS messages to send using an SQL SELECT statement, and insert the incoming SMS messages using an SQL INSERT statement. More information about such a setup can be found in our SQL to SMS setup guide. Database server specific configurations are listed below.
SQL to SMS configurations:
Send SMS from Microsoft SQL Server
Send SMS from Microsoft Access
Send SMS from Oracle
Send SMS from MySQL
Send SMS from PostgreSQL
Send SMS from SAP SQL Anywhere
Send SMS from Excel
Office users wish to use simple tools they are already familiar with and
tools that already contain the data they work with. Such tools are Microsoft
Excel, Access and E-mail. The following links help you provide tools for
your Office users to make it easy for them to send and receive SMS messages
from the office PC's. You can send SMS from Microsoft Excel,
Microsoft Access, you can create
Txt files with a list of phone numbers and messages text or
you can use an Email to SMS configuration.
More information

Feature list
Check out the amazing feature of this super samera recorder software. Learn about recoring and viewing option and computer vision features.
System requirements
Find out the software and hardware requirements. In short you need a windows PC with an up to date processor and sufficient RAM.
PDF order form
You can download and fill out this form and send it to us in e-mail to info@ozeki.hu to start your purchase.
PDF Guide
You can download the Ozeki 10 SMS Gateway Product Guide (151 MB) and read about the SMS communication software.Installation guide
How to install
Check out this step by step installation guide. It will show you how you can install this Ozeki product using the Ozeki app store.
Create admin password
This guide provides you information about how you can create a password for your admin account.
Product activation
In this guide, you can learn about how you can activate your Ozeki 10 product with the purchased serial number.Developers guide
SMS from/to Database
Learn about, how you can connect Ozeki SMS Gateway to a selected database server. Select from many of the supported database servers.
HTTP SMS API
The HTTP API provides flexibility and simplicity to help developers in productivity and be able to add SMS functionality to any project.
PHP SMS API
By following this guide, you will be able to learn about how you can use Ozeki PHP SMS API into your messaging solution.
C# SMS API
Use C#.Net to send and receive SMS from Visual Studio. Check out the C# SMS api reference manual, or read one of the following articles:How to send sms from C#
How to receive sms in C#

VB.NET SMS API
This guide helps you to learn how to manage SMS messages using Visual Basic.NET applications.Connections

SMPP Connection
Learn about, how to setup an SMPP SMS client connection. SMPP stands is a very popular choice among SMS service providers.
UCP/EMI Connection
The Universal Conputer Protocol and its extension, External Machine Interface is a greate choice to connect to short message service centers for mobile phones.
CIMD2 Client Connection
Learn about how you can set up a CIMD2 SMS client connection in Ozeki SMS Gateway. The CIMD2 interface transfers messages between applications and the SMS Provider.HTTP Client Connection
Learn about how you set up a HTTP SMS client connection in Ozeki SMS Gateway. By using this solution, you will be able to communicate with web applications.Android SMPP
This guide gives you information about how you can set up an Android SMS client connection in Ozeki SMS Gateway.SMS Modem
The following guide is about to demonstrate how you can connect your GSM modem to your PC and configure it with Ozeki SMS Gateway.SMS Modem Pool
SMS modem pools contain many GSM modems. They give you several phone numbers and high capacity.
SMS Service Providers
Ozeki offers native connection to many on-line SMS service providers. Check out the list of supported On-line SMS services.Applications
Standard User
With Ozeki SMS Gateway Standard user you can log in to the grafical user interface and you are able to send SMS. And you can investigate the details of the delivery of the message.Autoreply SMS
Ozeki SMS Gateway has 3 type of Autoreply Users which are used for automatically replying SMS messages or forwarding them to any recipient.Email to SMS
Ozeki SMS Gateway enables you to setup email to SMS forwarding. You can connect email clients, such as Windows Mail or Mozilla Thunderbird directly, or you can use IMAP, POP3 or SMTP with your email servers.SMS from/to File
Ozeki SMS Gateway's File User is capable to send and receive SMS messages in different file formats. Your application can place these files in proper directories to send SMS messages.SMS from/to FTP
Ozeki SMS Gateway's FTP to SMS User can synchronize directories with SMS Gateway through standard FTP, FTPS or SFTP protocols.Application starter
Ozeki SMS Gateway's Application Starter User can run any process or application in case an SMS message arrives. You simply need to provide the file path.Programing languages

C#
This tutorial helps you get started with C#. It explains what you need to write your first C# program.
F#
This tutorial helps you get started with F#. It explains what you need to write your first F# program.
VB
This tutorial helps you get started with Visual Basic. It explains what you need to write your first Visual Basic program.
Java
This tutorial helps you get started with Java. It explains what you need to write your first Java program.
JavaScript
This tutorial helps you get started with JavaScript. It explains what you need to write your first JavaScript program.
Node.js
This tutorial helps you get started with Node.js. It explains what you need to write your first Node.js program.
Kotlin
This tutorial helps you get started with Kotlin, and Android development. It explains what you need to write your first Kotlin program.
C/Cpp
This tutorial helps you get started with C/C++. It explains what you need to write your first C/C++ program.
Delphi
This tutorial helps you get started with Delphi. It explains what you need to write your first Delphi program.
PHP
This tutorial helps you get started with PHP. It explains what you need to write your first PHP program.
Objective C
This tutorial helps you get started with Objective-C. It explains what you need to write your first Objective-C program.
Perl
This tutorial helps you get started with Perl. It explains what you need to write your first Perl program.
Python
This tutorial helps you get started with Python. It explains what you need to write your first Python program.
Python flask
This is a helpful guide how you get started with Python flask. It explains what you need to write your first Python flask program.
Ruby
This tutorial helps you get started with Ruby. It explains what you need to write your first Ruby program.
Tcl/Tk
This tutorial helps you get started with Tcl/Tk. It explains what you need to write your first Tcl/Tk program.
Go
This tutorial helps you get started with Go. It explains what you need to write your first Go program.
R
This tutorial helps you get started with R. It explains what you need to write your first R program.