new ArgumentNullException();
    }
    if (raw.Length<20)
    {
     throw new ArgumentException();
    }

    this.m_Raw = raw;
    this.m_Time = time;
    this.m_HeaderLength = (raw[0] & 0xF) * 4;
    if ((raw[0] & 0xF) < 5) {throw new ArgumentException();}
    this.m_Precedence = (Precedence)((raw & 0xE0) >> 5);
    this.m_Delay = (Delay)((raw & 0x10) >> 4);
    this.m_Throughput = (Throughput)((raw & 0x8) >> 3);
    this.m_Reliability = (Reliability)((raw & 0x4) >> 2);
    this.m_TotalLength = raw * 256 + raw;
    if ( ! (this.m_TotalLength == raw.Length)) { throw new ArgumentException();} // invalid size of packet;
    this.m_Identification = raw * 256 + raw;
    this.m_TimeToLive = raw;

    m_Protocol = (Protocol)raw;

    m_Checksum = new byte;
    m_Checksum[0] = raw;
    m_Checksum = raw;

    try
    {
     m_SourceAddress = GetIPAddress(raw, 12);
     m_DestinationAddress = GetIPAddress(raw, 16);
    }
    catch (Exception e)
    {
     throw;
    }

    if (m_Protocol == Protocol.Tcp || m_Protocol == Protocol.Udp)
    {
     m_SourcePort = raw[m_HeaderLength] * 256 + raw[m_HeaderLength + 1];
     m_DestinationPort = raw[m_HeaderLength + 2] * 256 + raw[m_HeaderLength + 3];
    }
    else
    {
                
     m_SourcePort = -1;
     m_DestinationPort = -1;
    }
   }

   public string GetIPAddress(byte bArray, int nStart)
   {
    byte tmp = new byte;

    if (bArray.Length > nStart + 2)
    {
     tmp[0] = bArray[nStart];
     tmp = bArray[nStart + 1];
     tmp = bArray[nStart + 2];
     tmp = bArray[nStart + 3];
    }

    return tmp[0] + "." + tmp + "." + tmp + "." + tmp;
   }

   public int TotalLength
   {
    get { return m_TotalLength; }
   }

   public DateTime Time
   {
    get { return this.m_Time;


}
   }

   public Protocol Protocol
   {
    get { return this.m_Protocol; }
   }

   public string SourceAddress
   {
    get { return this.m_SourceAd