FastTrack Training. "Network Basics". "Understanding the OSI Model". Part one. Eddie Martin December 2012
About a year ago, I noticed an interesting and fascinating series of lectures by Eddie Martin, which, thanks to its history and real-life examples, as well as its tremendous learning experience, is amazingly comprehensible and allows you to gain an understanding of quite complex technologies.
We continue the cycle of 27 articles based on his lectures:
')
01/02: “Understanding the OSI Model” Part 1 / Part 2
03: "Understanding the Cisco Architecture"
04/05: “The Basics of Switching or Switches” Part 1 / Part 2
06: "Switches from Cisco"
07: "Area of ​​use of network switches, the value of Cisco switches"
08/09: "Basics of a Wireless LAN" Part 1 / Part 2
10: "Products in the field of wireless LAN"
11: The Value of Cisco Wireless LANs
12: Routing Basics
13: "The structure of routers, routing platforms from Cisco"
14: The Value of Cisco Routers
15/16: “The Basics of Data Centers” Part 1 / Part 2
17: "Equipment for data centers"
18: "The Value of Cisco in Data Centers"
19/20/21: "The Basics of Telephony" Part 1 / Part 2 / Part 3
22: "Cisco Collaboration Software"
23: The Value of Collaboration Products from Cisco
24: "The Basics of Security"
25: "Cisco Security Software"
26: "The Value of Cisco Security Products"
27: "Understanding Cisco Architectural Games (Review)"
And here is the first one.
When I met Cisco, I was just a customer. Now I have 30 years in the field of network technologies. I began my work by working with the military and the US air force. I actually traveled with President Reagan, so you can imagine how long ago it was. But not about it yet.
I was a client of the company, a buyer of their services and a user of their technologies. In fact, I was their client longer than an employee, because my Cisco career began in 1999. Then began the era of IP telephony.
I was the PBX guy who connected switches and routers and could not only serve as a telecommunications manager, but did a lot more. They needed a professional and they found me in South Carolina. If you work as an account manager or in a team of accountants, then your team will have a whole link in the so-called product sales specialists. They will explain to you how to work with this or that technology. The fact is that when I started, we were selling voice communication services. In my time, accountants could only issue invoices for conversations, now we have greatly complicated this process due to the development of networks. And these networks have never been so complex. What became a problem, a big problem, as clients hoped that the implementation of their tasks would be simple. And it became more difficult not from the point of view of network engineers, but in terms of technology, but what is great is that when we turn on our computers, they work. Customers are waiting for this. They are waiting for a miracle from us. The incredible rapid development of technology, namely their transformation, is something amazing.
That is why one of the tasks that I was assigned was the training of new account managers in my own team, since we hired a lot of people from outside, not from Cisco, and they had no experience in the field of network routing. They did not understand the switches and routers, but they could sell well. I usually say this - give me someone who can sell, I don’t worry about whether he understands technology, I can teach, but I can never learn to sell. I myself am not a seller. So it went in that direction.
The class was built and for the first three to six months I just kept telling them something, we had lunch, dinner and breakfast together. This is how the training went and we realized that this should be done for the entire staff of the company, even the most insignificant, because everyone influences our business and only this way they can fully understand its essence. Today we will focus more on choosing the approach to selling a product. In fairness, I note that service providers often sell these same services better than sellers.
I left Cisco at will in 2004 and opened my own consulting company. You can see here the inscription KEM consulting. Now I am sitting on the other side of the table. I was hired to go to customers and provoke them to talk about technology. You often have to talk with customers about technology, but I’m one of those who they ask, what was that seller talking about? How does this affect my business? Will it help me or not? Or will I just waste my resources? It's funny to be in my current situation, because now I can hear what they were saying about me, in a sense, when I was representing the interests of the vendor.
So, we will begin with a discussion about the OSI model. This model has existed for some time, actually longer than I am in this business. She appeared at the birth of network technologies. Before that, we essentially had a large computer and a private network through which everyone connected to this mainframe, everything was centralized, we used ancient terminals, more precisely, 3270 terminal emulators, because the terminals, as such, were absent. So that was the network, very private and very close. And then, suddenly, people began to build "personal computers" and began to wonder how to establish a connection between them.
I find it extremely funny, but after I finished working with the military, I began working with American Airlines, which at that time had the largest private data network in the world with a mainframe located in Tulsa, Oklahoma. And it launched the Saber computer reservation system used by four airlines. And once, in the mid-80s, we had a load of 140 thousand people who connected to this IBM mainframe. Then everyone used these freaking Raytheon terminals, summit terminals, someone's stupid term, be they wrong:
And then there are personal computers. The terminal at that time cost 75-85 dollars and it had two variants of colors - green and black or orange and black. And here we are replacing the terminal with a personal computer worth 4 thousand dollars. We connect them to a separate network that we had to create. And then the first thing we do is load a terminal emulator onto it so that it looks like a terminal. But we did it for the sake of productivity. Suddenly, we no longer needed typewriters, since we no longer needed to manually type anything. Printers have become network devices and now there is no need to know the person who could print. All these processes began to occur simultaneously. And at that moment, when the evolution of what we now call the network, there were a lot of competing technologies offered by different companies, with their own vision of how the network should function. Some of them could not function together. Here is a living example. IBM has released the first personal computers and American Airlines has bought a whole bunch of such computers. We installed them and connected them to the network using the Token Ring protocol. God, I loved this system. And here IBM produce new computers, with a more productive 8088 processor, instead of the old 8086, the model was called the RM Nimbus PC-186:
And they change the type of connectors to Ethernet. Now computers can not communicate with each other, they can not even communicate being connected to the same Ethernet network. Token Ring does not work with Ethernet, Ethernet works completely differently. In the end, they had to make it all work together, and at that moment, in a big way, the OSI model appeared.
Today we should not worry about it. Ethernet is used everywhere, and Token Ring lovers like me have been out of work, licked wounds. Like all these people who have contributed to ATM and other similar technologies that are a thing of the past today, since we have only Ethernet left. I usually say this joke later, but I'd better say it now. How do you say Ethernet from a Cisco perspective? Cisco. This is Ethernet. You know that I worked at CISCO, it was we who started offering these technologies to people and we gave the client a choice of options: ATM switches, Token Ring or Ethernet. Clients themselves chose the technology they needed. And what happened in the end? We almost did not sell ATM or Token Ring switches and now we do not sell them at all. We can adapt them if necessary, but we do not sell ourselves. There are no more products for a network core other than Ethernet, because it is one.
But the OSI model for vendors and organizations is, above all, a great way to explain why network technologies exist at all. There are many representatives of the industry among us today and I will ask you a traditional question. Why do people even buy routers and switches? Why do they need all these wireless technologies and stuff? Why do they invest their money in it? They need software applications, right? All these applications are the most important thing in the world for our customers.
I will show you the whole OSI model and all its seven layers. And I will need to tell you why customers need it and why we are sitting here now. We need to show them that they need these technologies to conduct their business. They need these routers and switches for business to flourish. The only reason a customer buys a router and a switch is to access applications.
So, we begin to disassemble the model and meet the seventh level. The application tier is the final set of protocols required to access network resources.
What is a protocol? This is a set of rules that we set. That is, to connect to a printer or server, we need this set of protocols. In fact, customers buy all these routers and switches in order to use applications, to have access to the web, which also works by protocol. This is the only reason they buy them. You say that I am not a genius, and not a local genius, but it took me a long time to reach this conclusion.
And in order to explain this, I would like to tell you about the case with my best friend who decided to open his own business. He studied at Virginia Tech as a chemical engineer and went to work at a naval shipyard in Charleston, South Carolina, as an engineer for chemical materials, which is one step lower. He worked on nuclear submarines, conducted a variety of studies, and suddenly, for no reason at all, he decided to completely change the direction of his activity. He decided to go back to where we grew up with him, to the southwest of Virginia. And he wanted to open his home health care company. He liked to live where he grew up. There are forests, mountains, beauty. In general, he opened his business and provided home services for people. There are many mining companies in our region and people often have lung problems for this reason. And he decided to help people undergo home treatment. It is easier for insurance and for hospitals and for the clients themselves. He began selling, for example, air compressors, so that a person could breathe pure oxygen in case of a problem with his lungs. And later he had to build an insurance company. For what he had to use the mail, regular mail, which we called a turtle as a joke. That is, he filled out the form, wrote the doctor's recommendations and sent these forms to the insurance. Then 90 or 95 days later he received his check for payment. And this is only if the insurance has confirmed everything from the first time. 95 days it took him to get his money. Not the best option. And then someone knocked on his door and said - we have the application you need, a server that will solve your problems. You will have a terminal or personal computer that will connect to this server and you will enter data and transfer it using new technologies. This technology in those days was called a modem. You will dial up to the server and transfer data to the insurance company. So, if you invest in this server, in the terminal and the application - this will reduce your wait from 95 to 70 days.
Are you interested, they asked? And how do you think Mack answered? Of course! Of course! He began to buy equipment that, among other things, had to be serviced. But as time went on, he thought that he needed more employees so that they could work and bring even more profit. And for this he needs network equipment, which will make it possible to connect to the server not one, but several computers at once. And so the first network appeared. This is basically. Basically. And then other people came and suggested that we should have another server on the network, since we have a lot of equipment and we do not even know how much and where and when it should be served. We have an inventory database, an application that needs to be connected to the network, which will let you know everything about your equipment. Is it interesting for you? Of course! Save me from having to do all this. We connected it to the network. After that, he had the service of nurses who worked in the homes of clients and he sent them to different parts of the city. He needed to know who and where and when he was and he created an application with a schedule of their work. Now imagine that you meet my friend Mac at the bar, and this is the most likely place where you can meet him outside the house, and ask him a question - what do you consider most important for your business? He will answer that this is what gives him access to the applications. With the development of technology, he had routers and so on, but the main thing is that they give him access to applications. How much money does Cisco switches and routers bring? 52 percent profit. Approximately 35-37 percent of them are switches and the rest are routers. These are the basic products. But they are also needed only to provide access to applications. That is why we need to make sure that we effectively interact with customers and understand what they need, and they need to use applications.
Now the term of the decision on its payments has been reduced from 95 to 45 days. If you have a newer technology, which will reduce the waiting time to 40 days - Mac will be glad. Show it to him. Only geeks like you and I are interested in such technologies, but we have no money. We do not scatter them. I have a wife and two children and I will tell you honestly, I have no money. We need to understand what is important for the client and give it to him, or rather what he sees as valuable for himself, and these are applications. He just doesn’t need cool switches and routers, and we made really awesome products, but he should understand why they can be useful to him, for which applications they can be used. The network exists solely to use applications! Take another example.
Mac has a router, to which more routers are connected in various places, his network is now wide. What if a young employee here and another employee from another network segment decide to install the latest version of a new game, like Doma or something else, on their computers? They will want to play on the network, fight with each other. They will phone and agree to download the game and play during lunch. They will need an intermediary who will transfer this high definition video and the game and the network can become quite busy. We need the network to be smarter, it must prioritize, the so-called QoS. It should set primary tasks above such games. Mack will say that for him working servers are much more important, they are in the first place, and everything else is on the third. Should the network somehow understand its priorities? Yes, but this requires a smart network, and that’s what we do at Cisco.
This we did in the 90s. We have invested millions and even billions of dollars in order to make our decisions smarter and determine what is more important in a particular network. A normal packet or a packet containing a frame, which packet can be delayed and which one is not. What was determined by QoS. We started broadcasting voice over a data network, and then we really began to use priorities, this is how IP telephony appeared. The network must meet our business objectives. And she can, if she is smart enough. Cisco does just that and offers people not only switches and routers, but also applications that can make them smart, otherwise the network will not work and customers will not get what they paid for. In the future, I will tell you about the servers that we use for work. But the main thing is the applications that our users need. It’s interesting for you and me to talk about technologies and protocols, but our clients only think about their business. They wake up in the morning and do not think that they need a new switch or router. They think that the economy is in a bad state and they need a successful business, they want to survive. They want their business to flourish and bring it as much profit as possible. We must relate our efforts to their demands. We must follow our strategy. And this is simple when you are a local manager, but if you are a regional manager and you have 1,200 clients, it becomes difficult to act in accordance with the strategy. But if you try to ask at least a couple of questions to customers, the strategy will be easier to line up. You will be able to think outside the patterns and empower clients. Understand that we need to constantly find out how we can strategically help our clients' businesses. This is what I do as a consultant. Implementation sometimes changes the picture completely. So we discussed the seventh level - the level of applications, which really is the most important level for me.
Go down to the level below. This is the presentation layer, which serves as a kind of adapter. He makes a picture from the JPG image so that we can send it. The application sees the image as an object and turns it into a JPG file. We are adapting this facility. The text gets its format, its picture, it makes it possible to turn all zeros and ones into the objects we need. Adapt them to your needs. But this is not all, we have added here some functions and settings. I will explain this with the example of an Internet browser. How many browsers do we know? Chrome, Internet Explorer, Firefox and many others. They all use the same protocol. Which one HTTP For example, I want to send a PowerPoint presentation to your computer. Let's call this file sales.ppt. But how will the network understand what format this document is? When the creators of PowerPoint thought about this task, the task of transferring files, they knew they would run into it.
And they came up with a file transfer protocol called File Transfer Protocol or FTP protocol. If I want to send an email from one mail server to another, then I use a simple protocol for mail or SMTP (Simple Mail Transfer Protocol).If I need network management, then I use the Simple Network Management Protocol (SNMP). And all these are standard applications that you can use for your own purposes.
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At the beginning of my career, I myself did not understand how to talk with clients and how to conduct presentations in general, but I was told that this was a necessary skill. I was afraid that I would begin to tell abstruse things and people would just fall asleep from boredom. I suggest you use my abstract examples in working with clients. No need to go into technical details, the main thing is to talk about the principle of operation.
Go ahead…
FastTrack Training. "Network Basics". "Understanding the OSI Model". Part two. Eddie Martin December 2012
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We continue the cycle of 27 articles based on his lectures:
')
01/02: “Understanding the OSI Model” Part 1 / Part 2
03: "Understanding the Cisco Architecture"
04/05: “The Basics of Switching or Switches” Part 1 / Part 2
06: "Switches from Cisco"
07: "Area of ​​use of network switches, the value of Cisco switches"
08/09: "Basics of a Wireless LAN" Part 1 / Part 2
10: "Products in the field of wireless LAN"
11: The Value of Cisco Wireless LANs
12: Routing Basics
13: "The structure of routers, routing platforms from Cisco"
14: The Value of Cisco Routers
15/16: “The Basics of Data Centers” Part 1 / Part 2
17: "Equipment for data centers"
18: "The Value of Cisco in Data Centers"
19/20/21: "The Basics of Telephony" Part 1 / Part 2 / Part 3
22: "Cisco Collaboration Software"
23: The Value of Collaboration Products from Cisco
24: "The Basics of Security"
25: "Cisco Security Software"
26: "The Value of Cisco Security Products"
27: "Understanding Cisco Architectural Games (Review)"
And here is the first one.
FastTrack Training. "Network Basics". "Understanding the OSI Model". Part one. Eddie Martin December 2012
When I met Cisco, I was just a customer. Now I have 30 years in the field of network technologies. I began my work by working with the military and the US air force. I actually traveled with President Reagan, so you can imagine how long ago it was. But not about it yet.
I was a client of the company, a buyer of their services and a user of their technologies. In fact, I was their client longer than an employee, because my Cisco career began in 1999. Then began the era of IP telephony.
I was the PBX guy who connected switches and routers and could not only serve as a telecommunications manager, but did a lot more. They needed a professional and they found me in South Carolina. If you work as an account manager or in a team of accountants, then your team will have a whole link in the so-called product sales specialists. They will explain to you how to work with this or that technology. The fact is that when I started, we were selling voice communication services. In my time, accountants could only issue invoices for conversations, now we have greatly complicated this process due to the development of networks. And these networks have never been so complex. What became a problem, a big problem, as clients hoped that the implementation of their tasks would be simple. And it became more difficult not from the point of view of network engineers, but in terms of technology, but what is great is that when we turn on our computers, they work. Customers are waiting for this. They are waiting for a miracle from us. The incredible rapid development of technology, namely their transformation, is something amazing.
That is why one of the tasks that I was assigned was the training of new account managers in my own team, since we hired a lot of people from outside, not from Cisco, and they had no experience in the field of network routing. They did not understand the switches and routers, but they could sell well. I usually say this - give me someone who can sell, I don’t worry about whether he understands technology, I can teach, but I can never learn to sell. I myself am not a seller. So it went in that direction.
The class was built and for the first three to six months I just kept telling them something, we had lunch, dinner and breakfast together. This is how the training went and we realized that this should be done for the entire staff of the company, even the most insignificant, because everyone influences our business and only this way they can fully understand its essence. Today we will focus more on choosing the approach to selling a product. In fairness, I note that service providers often sell these same services better than sellers.
I left Cisco at will in 2004 and opened my own consulting company. You can see here the inscription KEM consulting. Now I am sitting on the other side of the table. I was hired to go to customers and provoke them to talk about technology. You often have to talk with customers about technology, but I’m one of those who they ask, what was that seller talking about? How does this affect my business? Will it help me or not? Or will I just waste my resources? It's funny to be in my current situation, because now I can hear what they were saying about me, in a sense, when I was representing the interests of the vendor.
So, we will begin with a discussion about the OSI model. This model has existed for some time, actually longer than I am in this business. She appeared at the birth of network technologies. Before that, we essentially had a large computer and a private network through which everyone connected to this mainframe, everything was centralized, we used ancient terminals, more precisely, 3270 terminal emulators, because the terminals, as such, were absent. So that was the network, very private and very close. And then, suddenly, people began to build "personal computers" and began to wonder how to establish a connection between them.
I find it extremely funny, but after I finished working with the military, I began working with American Airlines, which at that time had the largest private data network in the world with a mainframe located in Tulsa, Oklahoma. And it launched the Saber computer reservation system used by four airlines. And once, in the mid-80s, we had a load of 140 thousand people who connected to this IBM mainframe. Then everyone used these freaking Raytheon terminals, summit terminals, someone's stupid term, be they wrong:
And then there are personal computers. The terminal at that time cost 75-85 dollars and it had two variants of colors - green and black or orange and black. And here we are replacing the terminal with a personal computer worth 4 thousand dollars. We connect them to a separate network that we had to create. And then the first thing we do is load a terminal emulator onto it so that it looks like a terminal. But we did it for the sake of productivity. Suddenly, we no longer needed typewriters, since we no longer needed to manually type anything. Printers have become network devices and now there is no need to know the person who could print. All these processes began to occur simultaneously. And at that moment, when the evolution of what we now call the network, there were a lot of competing technologies offered by different companies, with their own vision of how the network should function. Some of them could not function together. Here is a living example. IBM has released the first personal computers and American Airlines has bought a whole bunch of such computers. We installed them and connected them to the network using the Token Ring protocol. God, I loved this system. And here IBM produce new computers, with a more productive 8088 processor, instead of the old 8086, the model was called the RM Nimbus PC-186:
And they change the type of connectors to Ethernet. Now computers can not communicate with each other, they can not even communicate being connected to the same Ethernet network. Token Ring does not work with Ethernet, Ethernet works completely differently. In the end, they had to make it all work together, and at that moment, in a big way, the OSI model appeared.
Today we should not worry about it. Ethernet is used everywhere, and Token Ring lovers like me have been out of work, licked wounds. Like all these people who have contributed to ATM and other similar technologies that are a thing of the past today, since we have only Ethernet left. I usually say this joke later, but I'd better say it now. How do you say Ethernet from a Cisco perspective? Cisco. This is Ethernet. You know that I worked at CISCO, it was we who started offering these technologies to people and we gave the client a choice of options: ATM switches, Token Ring or Ethernet. Clients themselves chose the technology they needed. And what happened in the end? We almost did not sell ATM or Token Ring switches and now we do not sell them at all. We can adapt them if necessary, but we do not sell ourselves. There are no more products for a network core other than Ethernet, because it is one.
But the OSI model for vendors and organizations is, above all, a great way to explain why network technologies exist at all. There are many representatives of the industry among us today and I will ask you a traditional question. Why do people even buy routers and switches? Why do they need all these wireless technologies and stuff? Why do they invest their money in it? They need software applications, right? All these applications are the most important thing in the world for our customers.
I will show you the whole OSI model and all its seven layers. And I will need to tell you why customers need it and why we are sitting here now. We need to show them that they need these technologies to conduct their business. They need these routers and switches for business to flourish. The only reason a customer buys a router and a switch is to access applications.
So, we begin to disassemble the model and meet the seventh level. The application tier is the final set of protocols required to access network resources.
What is a protocol? This is a set of rules that we set. That is, to connect to a printer or server, we need this set of protocols. In fact, customers buy all these routers and switches in order to use applications, to have access to the web, which also works by protocol. This is the only reason they buy them. You say that I am not a genius, and not a local genius, but it took me a long time to reach this conclusion.
And in order to explain this, I would like to tell you about the case with my best friend who decided to open his own business. He studied at Virginia Tech as a chemical engineer and went to work at a naval shipyard in Charleston, South Carolina, as an engineer for chemical materials, which is one step lower. He worked on nuclear submarines, conducted a variety of studies, and suddenly, for no reason at all, he decided to completely change the direction of his activity. He decided to go back to where we grew up with him, to the southwest of Virginia. And he wanted to open his home health care company. He liked to live where he grew up. There are forests, mountains, beauty. In general, he opened his business and provided home services for people. There are many mining companies in our region and people often have lung problems for this reason. And he decided to help people undergo home treatment. It is easier for insurance and for hospitals and for the clients themselves. He began selling, for example, air compressors, so that a person could breathe pure oxygen in case of a problem with his lungs. And later he had to build an insurance company. For what he had to use the mail, regular mail, which we called a turtle as a joke. That is, he filled out the form, wrote the doctor's recommendations and sent these forms to the insurance. Then 90 or 95 days later he received his check for payment. And this is only if the insurance has confirmed everything from the first time. 95 days it took him to get his money. Not the best option. And then someone knocked on his door and said - we have the application you need, a server that will solve your problems. You will have a terminal or personal computer that will connect to this server and you will enter data and transfer it using new technologies. This technology in those days was called a modem. You will dial up to the server and transfer data to the insurance company. So, if you invest in this server, in the terminal and the application - this will reduce your wait from 95 to 70 days.
Are you interested, they asked? And how do you think Mack answered? Of course! Of course! He began to buy equipment that, among other things, had to be serviced. But as time went on, he thought that he needed more employees so that they could work and bring even more profit. And for this he needs network equipment, which will make it possible to connect to the server not one, but several computers at once. And so the first network appeared. This is basically. Basically. And then other people came and suggested that we should have another server on the network, since we have a lot of equipment and we do not even know how much and where and when it should be served. We have an inventory database, an application that needs to be connected to the network, which will let you know everything about your equipment. Is it interesting for you? Of course! Save me from having to do all this. We connected it to the network. After that, he had the service of nurses who worked in the homes of clients and he sent them to different parts of the city. He needed to know who and where and when he was and he created an application with a schedule of their work. Now imagine that you meet my friend Mac at the bar, and this is the most likely place where you can meet him outside the house, and ask him a question - what do you consider most important for your business? He will answer that this is what gives him access to the applications. With the development of technology, he had routers and so on, but the main thing is that they give him access to applications. How much money does Cisco switches and routers bring? 52 percent profit. Approximately 35-37 percent of them are switches and the rest are routers. These are the basic products. But they are also needed only to provide access to applications. That is why we need to make sure that we effectively interact with customers and understand what they need, and they need to use applications.
Now the term of the decision on its payments has been reduced from 95 to 45 days. If you have a newer technology, which will reduce the waiting time to 40 days - Mac will be glad. Show it to him. Only geeks like you and I are interested in such technologies, but we have no money. We do not scatter them. I have a wife and two children and I will tell you honestly, I have no money. We need to understand what is important for the client and give it to him, or rather what he sees as valuable for himself, and these are applications. He just doesn’t need cool switches and routers, and we made really awesome products, but he should understand why they can be useful to him, for which applications they can be used. The network exists solely to use applications! Take another example.
Mac has a router, to which more routers are connected in various places, his network is now wide. What if a young employee here and another employee from another network segment decide to install the latest version of a new game, like Doma or something else, on their computers? They will want to play on the network, fight with each other. They will phone and agree to download the game and play during lunch. They will need an intermediary who will transfer this high definition video and the game and the network can become quite busy. We need the network to be smarter, it must prioritize, the so-called QoS. It should set primary tasks above such games. Mack will say that for him working servers are much more important, they are in the first place, and everything else is on the third. Should the network somehow understand its priorities? Yes, but this requires a smart network, and that’s what we do at Cisco.
This we did in the 90s. We have invested millions and even billions of dollars in order to make our decisions smarter and determine what is more important in a particular network. A normal packet or a packet containing a frame, which packet can be delayed and which one is not. What was determined by QoS. We started broadcasting voice over a data network, and then we really began to use priorities, this is how IP telephony appeared. The network must meet our business objectives. And she can, if she is smart enough. Cisco does just that and offers people not only switches and routers, but also applications that can make them smart, otherwise the network will not work and customers will not get what they paid for. In the future, I will tell you about the servers that we use for work. But the main thing is the applications that our users need. It’s interesting for you and me to talk about technologies and protocols, but our clients only think about their business. They wake up in the morning and do not think that they need a new switch or router. They think that the economy is in a bad state and they need a successful business, they want to survive. They want their business to flourish and bring it as much profit as possible. We must relate our efforts to their demands. We must follow our strategy. And this is simple when you are a local manager, but if you are a regional manager and you have 1,200 clients, it becomes difficult to act in accordance with the strategy. But if you try to ask at least a couple of questions to customers, the strategy will be easier to line up. You will be able to think outside the patterns and empower clients. Understand that we need to constantly find out how we can strategically help our clients' businesses. This is what I do as a consultant. Implementation sometimes changes the picture completely. So we discussed the seventh level - the level of applications, which really is the most important level for me.
Go down to the level below. This is the presentation layer, which serves as a kind of adapter. He makes a picture from the JPG image so that we can send it. The application sees the image as an object and turns it into a JPG file. We are adapting this facility. The text gets its format, its picture, it makes it possible to turn all zeros and ones into the objects we need. Adapt them to your needs. But this is not all, we have added here some functions and settings. I will explain this with the example of an Internet browser. How many browsers do we know? Chrome, Internet Explorer, Firefox and many others. They all use the same protocol. Which one HTTP For example, I want to send a PowerPoint presentation to your computer. Let's call this file sales.ppt. But how will the network understand what format this document is? When the creators of PowerPoint thought about this task, the task of transferring files, they knew they would run into it.
And they came up with a file transfer protocol called File Transfer Protocol or FTP protocol. If I want to send an email from one mail server to another, then I use a simple protocol for mail or SMTP (Simple Mail Transfer Protocol).If I need network management, then I use the Simple Network Management Protocol (SNMP). And all these are standard applications that you can use for your own purposes.
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At the beginning of my career, I myself did not understand how to talk with clients and how to conduct presentations in general, but I was told that this was a necessary skill. I was afraid that I would begin to tell abstruse things and people would just fall asleep from boredom. I suggest you use my abstract examples in working with clients. No need to go into technical details, the main thing is to talk about the principle of operation.
Go ahead…
FastTrack Training. "Network Basics". "Understanding the OSI Model". Part two. Eddie Martin December 2012
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