/**

 * \brief network packets

 */

	/**

	 * Create an empty packet.

	 */

	/**

	 * Create a packet with a zero-filled payload.

	 * The memory necessary for the payload is not allocated:

	 * it will be allocated at any later point if you attempt

	 * to fragment this packet or to access the zero-filled

	 * bytes.

	 * 

	 * \param size the size of the zero-filled payload

	 */

	/**

	 * Create a new packet which contains a fragment of the original

	 * packet.

	 *

	 * \param start offset from start of packet to start of fragment to create

	 * \param length length of fragment to create

	 * \returns a fragment of the original packet

	 */

	/**

	 * \returns the size in bytes of the packet (including the zero-filled

	 *          initial payload)

	 */

	/**

	 * Add chunk to this packet. This method invokes the

	 * ns3::Chunk::addTo method to request the chunk to serialize

	 * itself in the packet buffer.

	 *

	 * \param chunk a pointer to the chunk to add to this packet.

	 */

	/**

	 * Deserialize chunk from this packet. This method invokes the

	 * ns3::Chunk::peekFrom method to request the chunk to deserialize

	 * itself from the packet buffer. This method does not remove

	 * the chunk from the buffer.

	 *

	 * \param chunk a pointer to the chunk to deserialize from the buffer

	 */

	/**

	 * Remove a deserialized chunk from the internal buffer.

	 * This method invokes ns3::Chunk::removeFrom to complete

	 * the work initiated by Packet::peek and ns3::Chunk::peekFrom.

	 *

	 * \param chunk a pointer to the chunk to remove from the internal buffer.

	 */

	/**

	 * Attach a tag to this packet. The tag is fully copied

	 * in a packet-specific internal buffer. This operation 

	 * is expected to be really fast.

	 *

	 * \param tag a pointer to the tag to attach to this packet.

	 */

	/**

	 * Remove a tag from this packet. The data stored internally

	 * for this tag is copied in the input tag if an instance

	 * of this tag type is present in the internal buffer. If this

	 * tag type is not present, the input tag is not modified. 

	 *

	 * This operation can be potentially slow and might trigger

	 * unexpectedly large memory allocations. It is thus

	 * usually a better idea to create a copy of this packet,

	 * and invoke removeAllTags on the copy to remove all 

	 * tags rather than remove the tags one by one from a packet.

	 *

	 * \param tag a pointer to the tag to remove from this packet

	 * \returns true if an instance of this tag type is stored

	 *          in this packet, false otherwise.

	 */

	/**

	 * Copy a tag stored internally to the input tag. If no instance

	 * of this tag is present internally, the input tag is not modified.

	 *

	 * \param tag a pointer to the tag to read from this packet

	 * \returns true if an instance of this tag type is stored

	 *          in this packet, false otherwise.

	 */

	/**

	 * Remove all the tags stored in this packet. This operation is

	 * much much faster than invoking removeTag n times.

	 */

	/**

	 * Concatenate the input packet at the end of the current

	 * packet.

	 *

	 * \param packet packet to concatenate

	 */

	/**

	 * Concatenate the fragment of the input packet identified

	 * by the offset and size parameters at the end of the current

	 * packet.

	 *

	 * \param packet to concatenate

	 * \param offset offset of fragment to copy from the start of the input packet

	 * \param size size of fragment of input packet to copy.

	 */

	/** 

	 * Remove size bytes from the end of the current packet

	 * It is safe to remove more bytes that what is present in

	 * the packet.

	 *

	 * \param size number of bytes from remove

	 */

	/** 

	 * Remove size bytes from the start of the current packet.

	 * It is safe to remove more bytes that what is present in

	 * the packet.

	 *

	 * \param size number of bytes from remove

	 */