System.IO.BinaryReader.ReadInt16 C# (CSharp) Method

        public virtual short ReadInt16()
        {
            FillBuffer(2);
            return (short)(_buffer[0] | _buffer[1] << 8);
        }

        public IPHeader(ArraySegment<byte> buffer)
        {

            using (var memoryStream = new MemoryStream(buffer.Array, buffer.Offset, buffer.Count))
            {
                using (var binaryReader = new BinaryReader(memoryStream))
                {
                    var versionAndHeaderLength = binaryReader.ReadByte();
                    var differentiatedServices = binaryReader.ReadByte();

                    DifferentiatedServices = (byte)(differentiatedServices >> 2);
                    CongestionNotification = (byte)(differentiatedServices & 0x03);

                    TotalLength = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());
                    Debug.Assert(TotalLength >= 20, "Invalid IP packet Total Lenght");
                    Identification = (ushort) IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());

                    _flagsAndOffset = (ushort)IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());

                    Ttl = binaryReader.ReadByte();

                    _protocol = binaryReader.ReadByte();

                    Checksum = IPAddress.NetworkToHostOrder(binaryReader.ReadInt16());

                    SourceAddress = new IPAddress(binaryReader.ReadUInt32());
                    DestinationAddress = new IPAddress(binaryReader.ReadUInt32());

                    HeaderLength = (versionAndHeaderLength & 0x0f) * 4;
                }
            }

            Raw = buffer;
            Data = new ArraySegment<byte>(buffer.Array, buffer.Offset + HeaderLength, MessageLength);
        }