BPSock (Basic Protocol Socket)

1. Facilitate the use of communication over socket connections.
2. Send queries and receive one or multiple responses.
3. Cancel queries in process.
4. Using a single socket connection to have several simultaneous communication channels.
5. Receive information without the need for an associated query, that is, once the connection is established, either end can send data to the other end even if the other end has not made a request.

Basic Protocol

2 option for communication:

          Asynchronous
CLIENT                  SERVER
Send ------------------> HookHandler
HookHandler <----------- Send

             Request
CLIENT                  SERVER
req -------------------> reqPoint
option: cancel --------> reqPoint
reqHandler <------------ reqPoint

Asynchronous: Both parties are always ready to receive data at any time, and both parties are can to send information at any time.

Request: The client sends data that is a request, the server responds to the requested data. Requests can be canceled as long as a response has not been received.

The connection has channel and the tags.The tags are used to identify the data that is being sent or received. we have 2 type de tag.

• Tag16: The maximum size of the tags is 16 bytes, use for Send and Hook
• Tag8: The maximum size of the tags is 8 bytes, use for (req) request and reqPoint

TAG cannot start with numbers.

The TAGs are identifiers the Hooks and reqPoints in the destinations, the Hooks and the reqPoints are handlers of received data.

To transmit several channels simultaneously, small chunks of data units are processed that are identified with a channel id. Each unit has a different id but the chunks that belong to a unit have the same id.

Each channel has at least two chunks, one for data and another to mark the end of the channel. The END DATA is a chunk with 0 data.

TAG:  tag1
 |
  \____> Channel id 1 (500bit)
   |      |
   |       \___> chunk id 1 Data 500bit
   |       |
   |       |____> chunk id 1 end 
   |
   |
    \__> Channel id 2 (700bit)
        |      
         \___> chunk id 2 Data 500bit
         |
         |____> chunk id 2 Data 200bit
         |
         |____> chunk id 2 end 

Data Maximum Transmission Unit (DMTU) is the maximum size of the data units.can be sent in. Always lee than 16,777,215.

The communications

the communications use: 2 bytes for the channel id, 16 bytes for the tag and 3 bytes (16,777,215) for the data size.

example:

id,    TAG                    ,  SIZE , DATA

_ _, _ _ _ _ _ _ _ _ _ _ _ _ _ , _ _ _ , AF02E...

01 00000000000000000000000074616731 000E10 AF02E...

Request Communication uses tag ephemera that are generated from a TAG8, the tag ephemera begin with a numerical character and serve to identify type, which can be:

1 is request
2 is response
3 is cancel

tag ephemera in the handlers does not include the first bit that sets the type, so it has a length of 15 bits. and to remove the prefix, only 7 bits must be removed.