C# Definitions:

struct RASDIALPARAMS {
   public int  dwSize;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst=256 + 1)]
   public string szEntryName;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst=128 + 1)]
   public string szPhoneNumber;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst=128 + 1)]
   public string szCallbackNumber;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst=256 + 1)]
   public string szUserName;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst=256 + 1)]
   public string szPassword;
   [MarshalAs(UnmanagedType.ByValTStr, SizeConst=15 + 1)]
   public string szDomain;
   public uint    dwSubEntry;
   public IntPtr dwCallbackId;
}

[StructLayout(LayoutKind.Sequential,CharSet = CharSet.Auto)]
internal class RASDIALPARAMS
{
   public int dwSize = Marshal.SizeOf(typeof(RASDIALPARAMS));
   [MarshalAs(UnmanagedType.ByValTStr,SizeConst =
       (int) RasFieldSizeConstants.RAS_MaxEntryName+1)]
   public string szEntryName = null;
   [MarshalAs(UnmanagedType.ByValTStr,SizeConst =
       (int) RasFieldSizeConstants.RAS_MaxPhoneNumber+1)]
   public string szPhoneNumber = null;
   [MarshalAs(UnmanagedType.ByValTStr,SizeConst =
       (int) RasFieldSizeConstants.RAS_MaxCallbackNumber+1)]
   public string szCallbackNumber = null;
   [MarshalAs(UnmanagedType.ByValTStr,SizeConst =
       (int) RasFieldSizeConstants.UNLEN+1)]
   public string szUserName = null;
   [MarshalAs(UnmanagedType.ByValTStr,SizeConst =
       (int) RasFieldSizeConstants.PWLEN+1)]
   public string szPassword = null;
   [MarshalAs(UnmanagedType.ByValTStr,SizeConst =
       (int) RasFieldSizeConstants.DNLEN+1)]
   public string szDomain = null;
   public int dwSubEntry = 0;
   public int dwCallbackId = 0;
}

VB Definition:

Structure RASDIALPARAMS
   Public TODO
End Structure

User-Defined Field Types:

None.

Notes:

None.