Here, I'm explaining how to integrate SMS api with your application. You can download complete code 
  from here Smart1SMSdemo1.zip (4.07 kb)

I will use below namespace. This is C#.net code snippet.
 

using System.Net;

using System.IO;

Note*: URL / API used here are imaginary. If you are using proxy server to access internet, you need to create an instance of Webproxy
          and notify your request object about this proxy instance.

string api = "http://demo.bsmart.in/SmartSendSMS.jsp?usr=@usr&pass=@pass&sid=@sid&msisdn=@msisdn&msg=@msg";

// setting up require paramaters

// you can store this sensitive data (credentials) in to database or web.config and fetch

string user = "Your_User_Name";

string password="Your_Password";

string sid = "Your_Sender_ID";

string msisdn =    "91980098900"          //  txtMobile.Text.Trim();

// encode the message to pass over http

string message = HttpUtility.UrlEncode("This is my test message");

//Buliding API with message and credentials

api = api.Replace("@usr",user).Replace("@pass",password).Replace("@sid",sid).Replace("@msisdn",msisdn).Replace("@msg",message);

// WebProxy proxy = new WebProxy("192.168.1.100",3321);

//uncomment below code if it requires credentials to access your network and update required

//NetworkCredential credentials = new NetworkCredential("UserNAme","Password")

//proxy.Credentials = credentials;

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(api);

// request.Proxy = proxy;

HttpWebResponse response = (HttpWebResponse)request.GetResponse();

StreamReader reader = new StreamReader(response.GetResponseStream());

// Display transaction ID which will be used later for tracking sms status.

Label1.Text = reader.ReadToEnd();

reader.Close();


 

Once you get the Transaction ID in a response, you need to store it at your end for future communication.
This transaction ID will be unique in our DB and yours. You can use this transaction ID to track status of SMS.
Attached code snippet explains how to get status of SMS.

To get your API visit www.bsmart.in and send a request for API credentials.

Thanks, Satalaj.