Protocol and Standard

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What is Protocol
A protocol is a set of rules that govern data communications.

Protocol defines: 

  • What is communicated 
  • How it is communicated 
  • When it is communicated 
The key elements of a protocol are: 

  • Syntax : structure/format of the data (the order in which they are presented). 
  • Semantics : meaning of each section of bits (does an address identify the route to be taken or the final destination of the message?) 
  • Timing : when data should be sent and how fast they can be sent. Example sender produces data at 100 Mbps but the receiver can process data at only 1 Mbps – thus the transmission will overload the receiver and data largely lost.
Standards 
Standards provides a model for development that makes it possible for a product to work regardless of the individual manufacturer.

Standards by fact
  • NOT been approved by an organized body but have been adopted as standards through widespread use.
  • Example. Hayes modem command set, IBM PC bus
Standards By laws
  • legislated by an officially recognized body-- e.g. by committee 
  • RS232
Why do we have Standards

  • Standards are supported by manufacturers and users to promote interoperability of equipment. 
  •  Open interface descriptions for ease of maintenance and support. 
  • Greater competition of products among manufacturers and resulting lower costs for users. 
  •  Standard tooling lowers manufacturing cost and increases their profit margin. 
  •  Standard interfaces allow fair comparison of performance among competing products.

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