## 7 IoT-Defined Application Protocols
### Advance Messaging Queuing Protocol (AMQP)  
AMQP has the tendency to support heterogeneous networks of nonwearable sensors, so its potential customers are industry machines and businesses. It supports messagingpublish/post in different technologies. Its reliability is enhanced by keeping the messaging to a fixed data and format, which is also the requirement of industry. The security, as well as performance, increases when messaging and requests are kept to a fixed format. The receiver knows the pattern of the message and can extract the data field from a fixed message structure. It is highly scalable for its heterogeneous networking and publish/subscribed approach [51]. The communication reliability has a level equal to TCP/IP. This means that the protocol for delivery of data for at least once, exactly once, and at most once guarantees the communication reliability. The protocol spans multiple operating systems simultaneously, and thus, the complexity in developing different industrial-level applications is reduced. AMQP is the backbone of modern data and acquisition systems and supports industrial IoT that includes the autonomous unmanned operation of machines and the self-healing capabilities of systems. Other proprietary messaging protocols are limited to single-user decision making for information exchange. Thus, integration for business partners is limited. Nodes must limit their functionality if they want heterogeneous platforms-based networking. AMQP can integrate hundreds of systems with quick solutions such as moving a ledger to the cloud or to some other network node, sharing daily meeting schedules, and making an appointment next week without disturbing the routine work. IoT becomes more flexible while using AMQP, and the addition of new clients is on the fingertips [51]. AMQP-based architecture possesses additional features that are not supported by HTTP client/server communication for the request/publish mechanism, whereas HTTP has certain features that are eliminated in AMQP for reliability, performance, security, and scalability. Some of these features are tabulated as under (Table 7). According to Gartner [6], an AMQP core can bundle up properties of protocols such as TCP/IP, SMTP, and HTTP and, thus, can form a standard IoT-based communication protocol for achieving software as a service (SaaS) and platform as a service (PaaS). This might reduce costs, as well as setup time, for deploying certain web-based business mod \begin{table}
\begin{tabular}{c c} \hline \hline
**Protocol Feature** & **AMPQ Status** \\ \hline Caching Read & Eliminated \\ \hline Put & Eliminated \\ \hline Delete & Eliminated \\ \hline Content Filtering & Added \\ \hline Header (Typed) & Added \\ \hline Transactions & Added \\ \hline Simple Authentication (SASL) & Added \\ \hline Symmetric Protocol & Added \\ \hline Socket Multiplexing & Added \\ \hline Out-of-order Notification & Added \\ \hline Server-initiated Transfer & Added \\ \hline Store and Forward & Added \\ \hline Publish and Subscribe & Added \\ \hline Defined Error Recovery & Added \\ \hline Well-defined Address & Added \\ \hline Content-based Routing & Added \\ \hline Credit-based Flow Control & Added \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Features that optimize AMQP for scalability, security, and homogeneous networking solutions. els. AMQP has all the ammunition to increase opportunities in technology, business, government, and industry. Comparison with MQTT  
IBM's MQTT is a single-core protocol, and this cannot compete with AMQP, which is the result of a collaboration of much user-driven firmware (UDF) [52]. 1. MQTT lacks durability and crashes without possessing archives for retrieval and recovery. 2. User must communicate simultaneously because no queueing mechanism is defined by the protocol in MQTT. 3. Windows Communication Foundation (WCF) and Java Message Service (JMS) are not configurable in MQTT, but AMQP supports Linux, Windows, and Solaris platforms for server configuration, Verbose, and messaging. 4.