 Hello everyone. Today we will be discussing about implementation of MQDT and CYB protocols. Here is the learning outcome. By the end of this session, students will be able to create MQDT broker and client to publish and subscribe to topics and receive messages. Here is the outline of this session. I will be first of all taking you through an introduction of Cloud MQDT broker. What exactly is Cloud MQDT broker and by relating it with one of the previous examples what we have seen in our earlier video and then I will show you how to initialize a broker and it's a client package by using Google's Chrome package called MQDT Lens. So it's a good moment here for the students to pause and think about how and think on how a client communicates with another client in the IoT scenario whenever we are employing MQDT protocol. So the solution is as we have already seen in the earlier video here we have a broker, a central broker which is surrounded by three clients as we have seen. If client A wants to sense a sort of temperature then it will be sensing it and it will directly send the message to broker. So here we generally refer this particular process as client A has sensed the temperature and it has published the data to broker. So now depending upon which other clients like client B and client C have actually subscribed to the temperature topic will only be receiving the data. On the other hand some other clients like client D who are non-subscribers I mean who didn't subscribe to the topic called temperature won't be sending any messages from the broker. So let's have a detailed look at how to initialize broker and what are the roles of broker. So basically the role of broker is to manage the protocol as well as the incoming and outgoing messages. Generally we call this message sending activity as a publish and whenever a particular client is getting some sort of message you know whenever it subscribes to a specific topic is known as subscribing. So in this case so let's have a detailed look about Cloud MQT. Cloud MQT is basically a hosted message broker for Internet of Things and as you are able to see we have a producer, broker and consumer. Like in the previous slide client A was actually a message producer which was then published to the broker and broker has taken care to properly publish the data further to those clients who have the role of subscribers and whenever we say that a particular client has subscribed to a certain broker it happens through an ID called topic. So this is a mechanism of identifying which people or which clients in the network are actually interested to get the message that is being published. Now let's have a detailed look at how to initialize MQT broker by using by browsing to the website called Cloud MQT. So here I am opening a website called cloudmqt.com. Here as you can see first of all you are supposed to log in so let me quickly log in and I have already mentioned I have already input my credentials so that I have already logged into this session. Now once you enter to this particular portal all you are supposed to do is click on list all instances if you are already created one or if you are trying to visit this for the first time then simply you are supposed to click on create new instance. I have already created it once so let me show you quickly how to create all these things. So you are supposed to cross these four steps before you begin initializing a sort of MQT broker. So as we are already logged in I have already put my credentials and I am able to log in to this Cloud MQT server and if you are trying to log in to this website for the first time you are supposed to click on create new instance and make sure that you have given a suitable name to this like I have given the name called IOT and then select the term I mean the plan as cute cat free because this is the only plan that is available which is offered free of cost on this website called Cloud MQT. So I will be going back and I will simply click on the instance that I have already created for this session. If I click on this name of the instance once it loads you would be able to see a couple of details which we will be using. So this is the current plan that we are using which is offered free of cost by this Cloud MQT based server. Now there are some important details that we are about to watch here that is the server address is what we generally refer it as address and the username and password is what we need to log in to this particular broker and then have an access to send messages I mean publish and get the things done. So the four important information so the four important things that we are supposed to focus generally is the server name there is this entire tailor.cloudmqt.com of course the username and password are the credentials which we would try to mention in our clients and of course the port number is one more important thing which will make sure that no two instances are getting clashed together. So along with this we so with this I will open a small chrome Google Chrome extension with a name called MQT lens you can easily go to Google Chrome web browser and install this. Once you install and open this the reason why we are using this is it can be easily used for publishing and subscribing to certain topics which are already live. So let me quickly show you how to put the details. So I'll first of all copy the address from cloud MQT server and give this a proper name like test then I'll paste that address over here now I'll copy the port address now I'll copy the port address and I need to enter username and password so simply copy paste these things and you may put it here. So what we are trying to do is currently we are trying to configure a MQT client. So this client would be connected to this MQT cloud and cloud impurity broker that is hosted online and we are trying to use this cute cat plan of its variants. Now once you do this simply click on create connection you should be able to see a green content like this otherwise if you don't put proper details then probably it will be showing with the help of some red color. Now let me first of all initialize a client here with a specific topic let it be temperature. So I have a client who is trying to subscribe so as you can easily see I have a topic called temperature and I have subscribed to it. Now this particular entity I mean the lower entity below this published heading is nothing but what the broker generally does. So if I post some data like temperature maybe 30 degrees and if I click on publish then this particular subscriber will be receiving that particular information. So this is how the data is transferred from the broker if it is published with a given topic name otherwise it can't. So on the other hand if I type temperature one to which nobody has subscribed I'll be clicking on subscribe now sorry I'll be clicking on publish now and let us see. So that message is sent to nobody. So this is how things often work in the back end with the help of a cloud impurity we'll be getting into the details like what are the various quality of services offered by MQTT. Here are the references used for this session. Thank you.