Cisco CCNA 200-301 – Cloud Computing

1. Introduction

Section, you’ll learn about cloud computing. This is another one of the new topics for this version of the CCNA exam. And Cisco are not going to test you on any kind of configuration or hands on details. Rather, we’re going to test you on the theory of cloud computing. Things that you’re most likely to be asked about on the exam are the different service models and the different deployment models. But I don’t want to just tell you what they are without giving you some context first. So I’ll start off by explaining what cloud computing is.

Before I can do that, I’ll tell you what the traditional models are that cloud computing can work along with, and then I will explain what cloud computing is. We’ll get into the different characteristics. I’ll also talk about virtualization as well, because it’s really important to understand that, to understand what’s happening in a cloud environment. And then we’ll get into the different deployment models, the different service models, et cetera. I’ll wrap everything up by summarizing the advantages of cloud computing. So that’s end of this section, you’ll have a really good understanding of what cloud computing is.

2. Traditional IT Deployment Models

Before you can understand what cloud solutions are, you need to know what we are comparing it to. So in this lecture, I’ll cover the traditional It deployment models of on premises solutions and colocation or colo services. First up, on premises solutions. So this is is your standard traditional set up where you own your own building as a company and all of the equipment is hosted in your building and you’ve paid for all the equipment and you own it all. So with a traditional on premises solution, all equipment is located in your building. All equipment is owned by you. And by you I mean the company. There are clear lines of demarcation. Everything in your building is your responsibility. The connections between your offices are your service providers responsibility. All of your equipment is capex. With Capex and Opex, capex is capital expenditure. And that’s anything that you pay a one off upfront fee for. Opex is operational expenditure and this is anything that you’re paying a recurring monthly fee for. So when you’re running on the traditional on premises solution, you buy your equipment upfront.

So that is a capex cost. New equipment will typically take over a week to deploy. You have to go through the approval process. Then you have to order the equipment. You have to wait for it to arrive on your site from whoever you bought it from. You then need to get it to the server room. You need to unbox it, you need to get it wrapped up, you then need to get it cabled. You need to install the operating system and any patches and you need to install the applications on there as well. The networking team need to configure the networking configuration. The server team need to do the installation and install the software on there. And if you’re using external storage, the storage team will need to configure that. So it’s an involved process and typically it’s going to take at least a week to deploy a new server or other equipment like your routers, your switches, firewalls, et cetera.

Another thing is you need to consider redundancy for any mission critical equipment. You’re not going to want to have any single points of failure, so you’re going to double up on those, which is again going to add to the complexity and also the cost. So that’s on premises didn’t need to talk about that so much because it’s very intuitive and pretty obvious what’s happening there. The next one that you might not be so aware of is Colo or colocation facilities. This is a data center location where the owner of the facility rents out space to external customers. The facility owner provides power, cooling and physical security for their customers, server storage and networking equipment. As a customer, obviously your staff, your users are not going to be sitting in a data center to do their work. They’ll still be sitting in your normal office. The normal office has got network connectivity to the data center and that is where your centralized servers are located. Independent Como providers such as Equinix is probably the best known one. They offer customers multiple network connectivity options through a choice of network service providers. So if you were in the US, for example, maybe at and T and Verizon and a few other ones are connected in there and when you put your equipment in the colo facility, you can take your choice of network providers.

The network service providers will also typically peer with each other in colo facilities. That’s how internet connectivity is built. So, the characteristics of a colo solution the colo provider owns the data center facility and is responsible for providing highly available power, cooling and physical security according to the terms of a service level agreement with you, the customer. You own your own server storage and networking equipment which is located inside the colo facility. So they’re providing the building infrastructure, but the actual It equipment is provided and owned by you. The connections between your offices and the colo are your network service providers responsibility. So with this, it shares a lot of the characteristics of an on premises solution. Your equipment within the colo facility is owned by you and again it’s paid for as an upfront capex cost.

The monthly colo hosting fees are a monthly recurring fee so that’s an opex cost. New equipment will typically take over a week to deploy because again it’s your own equipment and you’re configuring it all yourself. You have to order it, do all the configuration. Just like with on premises, it’s going to take over a week. Equipment requires technology refreshes. This was the same with on premises as well, meaning that hardware is going to get out of date and then you’re going to want to replace it with new technology, which again is going to be another capex cost. You need to consider redundancy for the hardware that you own, the same as in an on premise solution. You’re not going to want to have any single points of failure. Okay, so that was on prem premises and colo. And a colo facility is not a cloud solution. You’ll see why and you’ll see what a cloud solution is as we go through the rest of this section.

3. Defining Cloud Computing

In the last lecture, you learned about the traditional deployment models of on premises and colo or colocation facilities. In this lecture, I’ll explain what cloud computing is and compare it with the traditional deployment models. So there’s a lot of confusion about exactly what cloud computing is. Beginners tend to describe it as It services which are located somewhere else. Somewhere else is just some vague notion that it’s not inside the company building. But colo facilities are off premises, and they are not cloud and private cloud deployments are often on premises. So that definition really doesn’t work. We need a better one. And there is a de facto definition of what cloud computing is. It comes from the NISS, which is the National Institute of Standards and Technology. So they came up with this definition in 2011. Cloud computing is a model for enabling ubiquitous, convenient on demand network access to a shared pool of configurable computing resources. For example, network servers, storage applications, and services that can be rapidly provisioned and released with minimal management effort or service provider interaction. Okay, I didn’t say it was a very clear cut definition, but that is the standard definition of what cloud computing is. Luckily, in the same document that the NIST released this definition, they also specified the characteristics of cloud computing. And they really nailed down what cloud computing is.

But just like the definition is along, there’s more than one characteristic that really defines cloud computing. The first one is on demand self service. Again from the NIST. A consumer can unilaterally provision computing capabilities such as server time and network storage as needed, automatically, without requiring human interaction with each service provider. So this is very different than what you see with an on premises or a colo solution. With those traditional solutions, whenever a department wants a new server, they raise a ticket, a request with the It department, and then we go through that long process that I described in the last lecture about ordering the server, getting it racked up, getting it cabled.

The network, the server and the storage team then have to configure everything before the server goes live with cloud computing versus on demand self service, where it does not require individuals in the It teams to put this thing together. Normally it will use a really convenient GUI front end, a web based tool that users, whether it’s another company or maybe an internal department, if you’re doing private cloud, can provision their own services, such as servers. And in the next lecture, I’ll give you an example of that working. The next characteristic is rapid elasticity. Capabilities can be elastically, provisioned and released, in some cases automatically to scale rapidly outward and inward, commensurate with demand to the consumer. The capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time.

So what elasticity is you can think of it like an elastic band where you can pull it apart and then it will stretch back again as well. With elasticity, you can provision the amount of resources that you require very quickly. You can very quickly scale out when you need more and you can very quickly scale back in when you need less. And you only pay for what you’re using at the time. Next one is broad network access. So the first two characteristics really their characteristics of cloud, and it’s very hard to do that with an on premises or a colo solution. The broad network access, really this applies to on premises and colo as well, normally.

But for a service to be classified as a cloud service, it also has to meet this characteristic with the characteristics. It’s not a case of a cloud service just has to meet one of those. A cloud service has to meet all of these characteristics. So broad network access the capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous, thicker, thin client platforms like mobile phones, tablets, laptops and workstations. With a cloud service, it should be able to be accessed from anywhere from the company’s offices or from anywhere out on the Internet as well, and from a variety of different clients. Next one is resource pooling. The provider’s computing resources are pooled to serve multiple consumers using a multitenant model with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. So with cloud services, every customer or every internal department does not have their own separate dedicated hardware. The hardware is shared and this brings the cost down. Because there’s shared hardware, you don’t have to buy separate hardware for everybody that is using it.

Usually it will be virtualized. And in a later lecture in this section, I’ll show you how the virtualization works. Next one is measured service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service, for example, storage, processing bandwidth, and active user accounts. With a cloud service, it’s always going to be an operational expenditure, it’s going to be a recurring monthly fee.

And the cloud provider needs some way of measuring how much of it you’re using as a customer so that they can bill you accordingly. Okay, that was it. That was all of the characteristics that made up a cloud service. In the next lecture, I’ll show you an example of actually provisioning some services in the cloud and you’ll see these characteristics in action. See you there.

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