AMQP Protocol in IoT

Introduction :

• AMQP full form of Advanced Message Queuing Protocol.
• Open standard for passing business messages between applications or organizations.
• Connects between systems and business processes.
• It is a binary application layer protocol.
• Basic unit of data is a frame.
• ISO standard : ISO/IEC 19464

AMQP Features

Message Delivery Guarantees

At-most-once

•   each message is delivered once or never

At-least-once

• each message is certain to be delivered, but may do so multiple times

Exactly-once

• message will always certainly arrive and do so only one

AMQP Frame Types

Nine AMQP frame types are defined that are used to initiate, control and tear down the transfer of messages between two peers:

• Open (connection open)
• Begin (session open)
• Attach (initiate new link)
• Transfer (for sending actual messages)
• Flow (controls message flow rate)
• Disposition (Informs the changes in state of transfer)
• Detach (terminate the link)
• End (session close)
• Close (connection close)

Components

AMQP Exchanges

Features

• Targeted QoS (Selectively offering QoS to links)
• Persistence (Message delivery guarantees)
• Delivery of messages to multiple consumers
• Possibility of ensuring multiple consumption
• Possibility of preventing multiple consumption
• High speed protocol

Applications

• Monitoring and global update sharing
• Connecting different systems and process to talk to each other.
• Allowing servers to respond immediate request quickly and delegate time consuming tasks for later processing.
• Distributing a message to multiple recipients for consumption.
• Enabling offline clients to fetch data at a later time.
• Introducing fully asynchronous functionality for systems.
• Increasing reliability and uptime of application deployments.