1.BYTE ORDER:
--------------

                      16 BIT
////////////////////////////////////////////////////////
//  MSB                //      LSB                    //
//  HIGH-ORDER BYTE    //      LOW-ORDER BYTE         //
//                     //                             //
////////////////////////////////////////////////////////
        ------------------------->BIG ENDIAN BYTE ORDER
       <------------------------- LITTLE ENDIAN BYTE ORDER


NETWORK BYTE ORDER(INTERNET PROTOCOLS):
  BIG ENDIAN BYTE ORDER
  MSB

HOST BYTE ORDER(SYSTEM BYTE ORDER):
  (IN  i80x86)
  LITTLE ENDIAN BYTE ORDER
  LSB



2. CONVERT VALUES BETWEEN HOST AND NETWORK BYTE ORDER
------------------------------------------------------

uint32_t htonl(uint32_t hostlong);
htons  host to network(short interger)
ntohl  host to network(interger)
ntohs  host to network(short interger)

3. CONVERT INTERNET HOST ADDRESS FROM NUMBERS AND DOTS INTO BINARY DATA IN NETWORK BYTE ORDER
in_addr_t inet_addr(const char *cp);


4. SOCKET
-------------------------
int socket (int NAMESPACE, int STYLE, int PROTOCOL)

4.1 Namespace and address format

	namespace(protocol family)		: start with 'PF_'
	address format for the namespace	: start with 'AF_'

 	Ejemplos:

  	AF_INET    ---  PF_INET
 	AF_INET6   ---  PF_INET6
  	AF_LOCAL   ---  PF_LOCAL

4.2 comunication Styles:
	int SOCK_STREAM (Pipes and FIFOs)
        int SOCK_DGRAM  (Datagrams)

4.3 Protocol
    For each combination of style and namespace there is a "default
    protocol", which you can request by specifying 0 as the protocol
    number.

4.4  Internet Socket Address Formats 

     AF_INET, AF_INET6
     struct sockaddr_in : represent socket addresses in the Internet namespace
         sa_family_t    sin_family   : address family - AF_INET
         struct in_addr sin_addr     : The Internet address of the host machine
         unsigned short int sin_port : The port number

4.5  Host Address Data Type
   
   struct in_addr	: Used in certain contexts to contain an IPv4 Internet host address 
         s_addr		: the host address number as an 'uint32_t'.



5. CONNECT TO  SOCKET
  A connection is asymmetric, the "client" acts to request a connection, 
  while the "server" makes a socket and waits for the connection request
  4.6.1 Making a Connection
    the client makes a connection
    
    int connect (int SOCKET, struct sockaddr *ADDR, socklen_t LENGTH)
    
    SOCKET: File descriptor SOCKET (cliente)
    ADDR,LENGTH: Server
    "connect" waits until the server responds to the request.