MicroSIP is a free, open-source, and highly portable SIP (Session Initiation Protocol) softphone for the Windows operating system. Built on the robust PJSIP stack, it is renowned for its incredibly small footprint, consuming less than 5 MB of RAM and requiring less than 2.5 MB of storage space. The application facilitates high-quality voice and video calls (using H264 and H263+ codecs) through any VoIP provider or directly via IP address, making it a versatile tool for both enterprise and personal use.
MicroSIP.exe volume 80
win32gui.SendMessage(hwnd, win32con.WM_COPYDATA, 0, ctypes.addressof(cds)) return True
microsip.exe sip:number@domain or microsip.exe number Hang Up All Calls: microsip.exe /hangupall Answer an Incoming Call: microsip.exe /answer Minimize to Tray: microsip.exe /hide Exit Program: microsip.exe /exit 2. Windows Messaging API (For Developers)
It also integrates the for managing SIP account configurations, which includes fields for Server, Proxy, Domain, Username, and Transport Protocol. The PJSIP integration is handled through a set of callbacks defined in mainDlg.cpp , which are triggered for different SIP events.
By modifying this C++ source code, a developer could fundamentally alter the application's behavior. For example, one could add a custom TCP/IP listening socket to the CmainDlg class to receive commands from a remote server, or add a new button to the UI that interacts with a local REST API.
is available under the GNU GPL v2 license for those looking to build custom versions. A Good Story: The Ghost in the SIP Stack
(expanded version for deep reference). Copy, share, and adapt as needed for your internal wiki or developer docs.
Note: Modifying this file programmatically requires a restart or an explicit reload command to force MicroSIP to accept the new configurations.
Once running, MicroSIP acts as a DDE server (service name: MicroSIP ). External applications can send DDE commands to:
Since it's based on PJSIP, advanced developers can inspect the SourceForge repository to see how the messaging hooks are implemented.
using System; using System.Runtime.InteropServices; public class MicroSIPController [DllImport("user32.dll", SetLastError = true)] private static extern IntPtr FindWindow(string lpClassName, string lpWindowName); [DllImport("user32.dll", CharSet = CharSet.Auto)] private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, ref COPYDATASTRUCT lParam); private const uint WM_COPYDATA = 0x004A; public struct COPYDATASTRUCT public IntPtr dwData; public int cbData; public string lpData; public static void SendAction(string actionCommand) // Find the MicroSIP window instance IntPtr hWnd = FindWindow("MicroSIP_WindowClass", null); if (hWnd == IntPtr.Zero) Console.WriteLine("MicroSIP is not running."); return; byte[] snoop = System.Text.Encoding.UTF8.GetBytes(actionCommand); int len = snoop.Length; COPYDATASTRUCT cds; cds.dwData = IntPtr.Zero; cds.cbData = len + 1; // Include null terminator cds.lpData = actionCommand; SendMessage(hWnd, WM_COPYDATA, IntPtr.Zero, ref cds); // Usage: // MicroSIPController.SendAction("action:dial?number=1234"); // MicroSIPController.SendAction("action:hangup"); Use code with caution. 4. Web Integration via URL Protocols
file located in the application's data folder. Key fields include: : SIP proxy address. : SIP extension identifier.
[StructLayout(LayoutKind.Sequential)] public struct COPYDATASTRUCT
using NDde.Client; var client = new DdeClient("MicroSIP", "control"); client.Connect(); client.Execute("[Dial(5551234)]", 60000); client.Disconnect();