Virtual Desktop Infrastructure (VDI) is a computing infrastructure based on a centralized control environment, where everybody is able to access terminals of the source information. VDI helps users to connect to a centrally placed OS and applications terminal via a network from their client terminals. In a traditional sense of personal computing, the computer is an integrated unit having the operating system (OS), the computer applications such as programs, and the hardware itself (a physical part). The traditional desktop experience, therefore, is the experience of having any user to access computing services applying an integrated and self-sufficient computer. It hosts its own OS and runs applications already installed into the hardware. Later, technologies emerged which allowed the user to connect the computer (client terminal or client device) to a network through a network card and physical ports. The latter ones may be installed into the hardware, or through a wireless network interface using modems attached to the computer. In a VDI setting though the hardware piece does not host the OS or the applications, on which it runs. However, it is connected to a central device such as a server, on which the OS and applications are hosted (Wannous, 2010).
This document will explore the use of VDI at universities. It will have various sections including the background of VDI, its application in corporate and large institutions, and VDI application at universities. The reason why the VDI implementation at universities is an interesting topic for me because of a rapidly rising demand for both software upgrades. It makes it very complicated for large institutions to adopt the piecewise computer hardware and software upgrades as well as the rising demand for the high speed data transfer across multiple user interfaces in a contemporary institutional setup. It makes it hard for institutions to effectively run and monitor users as well as meet the demands of thousands of high speed data connections.
The virtual desktop infrastructure as a concept has developed over several decades. It borrows its fundamental concepts from the parallel port networking systems being prevalent since the 1990s. During the period, typical computer networking infrastructures were based on the wired network topologies, such as ring networks, bus networks, star networks, mesh networks, and wireless networks. In addition, the original layered infrastructure with switches, hubs, and routers are still valid, whether the VDI network is wired or wireless. However, the bulk of VDI networks today are wireless, especially those ones confined within institutions. This arrangement allows a modern typical user, who most likely uses the network to access. In addition to a mobile user, most institutions also have established laboratories, libraries, and research centers, which may combine a wired and wireless network topology in order to meet their user demands (Wannous, 2010).
The virtual computing infrastructure has developed mainly in the last 50 years since the popularization of the mainframe infrastructure. Back then, the control for the typically isolated mainframes was done via a virtual network from the workstations detached from main units. Today, however, virtual networks, virtual machines (VMs), and applications are used extensively in test environments as well as research facilities (Malaric, Jurcevic, & Hegedu, 2008). Web based computer networks allow virtualized computing environments to be developed in which multiple user terminals can be assigned to virtual machines. Today, a significant amount of Virtual Networks (VNs) is designed using a dedicated Java Applet designer platform. It combines an integrated Graphic User Interface (GUI) capability to give an end user the multiple controls experience, allowing the realization of a reality feeling during the virtual network use. One of basic incentives in developing a virtual network at an academic institution is to enable a multiple access of computing or learning applications by students using one physical hardware infrastructure (Malaric, Jurcevic, & Hegedu, 2008).
In an ordinary virtual learning environment, the graphical user interfaces are used with computer simulations of an actual learning environment. It is done to give multiple users a simultaneous access to a system, which is programmed to respond exactly. It may be used in a real environment. For instance, students in the aviation sector may take the virtual pilot courses using computer applications modeled into virtual machines. They simulate the real piloting experience. In addition, universities today are designing computer virtual applications to enable students to take courses from home using a virtual private network (VPN). It may be guided by dedicated software applications that mimic the real class experience. Such a development is a key element in providing learning experience in situations where physical learning resources are limited. Otherwise, it may happen in such cases where students are unable to physically attend learning environments. One more example is the case, when an institution is piloting testing projects. The outcome may be hard to determine and may potentially involve harm.
The International Journal of Education and Research (IJER) has applied an illustration of virtual machines’ infrastructure as having a three layered arrangement with a hardware layer forming a basic element. Meanwhile the hardware visualization interlink forms the middle layer. The actual virtual machine interface forms a top infrastructure layer. It combines an operating system and other applications. The diagram below illustrates this concept.
In the conceptualization mentioned above, the virtual computing network shows an integrated technology. According to it, one physical machine (hardware) is programmed to operate two or more operating systems in a virtual interface. Therefore, this example displays an arrangement that allows two users to access two machines (operationally) being on one physical machine. Therefore, if carefully managed, the virtual computing environment can enable the limitless user experience using one physical infrastructure.
Hardware virtualization typically can be split into three concepts, including virtualization within one desktop, server visualization, and virtual desktop infrastructure. It is a primary focus on this paper (Class IT, 2014). Server visualization is based on the presence of the server which is used to perform the virtualization tasks. The desktop virtualization, like shown above, is the virtualization being done on the desktop. Virtual Desktop Infrastructure (VDI), however, is a combination of other two virtualization methods. There servers are used to host various virtual desktops; and every user can access the systems through the network.
Such a hybrid use of virtual computing resources allows optimization of network and hardware resources as well as allowing the faster allocation of dynamic network resources as the server recovery times are greatly reduced (Lunsford 2010). Virtual Desktop Infrastructure, when used by students for their computing needs in a campus, can allow them to access academic facilities using their home computers. Thus, they are able to access the school learning resources via Virtual Private Network (VPN). They are directed at Virtual Desktop Infrastructure through a secure connection at school and, therefore, in order to minimize the risk of network based attacks on their computers such as malwares and viruses. Once they reach the network, they are allocated the dynamic network access address using the network’s addressing system. The server then allocates them a virtual desktop through which they can access various applications. The other key benefit of using VDIs is the ability of the system to apply multiple operating systems and applications within the same hardware or the use of upgrade systems with hardware, with which such upgrades would ordinarily conflict.
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Miseviciene (2013) notes that software upgrade may render usable hardware as not being applied anymore. For instance, the current operating systems are already incompatible with the hardware built a decade ago or less, even though it is working perfectly. Upgrading such hardware to obtain the one which is compatible with the current software developed to meet challenging demands may be difficult and expensive. It is especially in the institutional setting where IT systems cost a big percentage of capital incentives. It may not be allocated substantial budgets after the installation to allow the complete overhaul. Other than programs and operating systems with incompatibility issues, IT administrators today are also faced with solving numerous addressing and communication protocols among various network components. These inconsistencies may threaten the functionality of entire networks or branches thereof potentially crippling investments worth millions of dollars for huge institutions (Office of Information Technology, 2014). Thus, VDI is an important development in systems where addressing conflicts may arise. One such example is the use of Dynamic Link Libraries (DLL). It is a concept normally used by modern computers to allocate resources to users. DLL versions may greatly crash, potentially crippling some high performance networks. Once networks fail due to some upgrade inconsistencies, VDI interfaces may help with the integration of all addresses via a virtual address allocation system. It bypasses the local addressing tables of original or parent systems. It helps to harmonize all communication processes and, thus, realize a fast and seamless interface between otherwise incompatible systems (Miseviciene, 2013). The figure below shows the typical VDI infrastructural design.
The VDI system above has been modeled to provide the rich experience with a web access, but it can be substituted to reflect such a system using a Local Area Network for institutions. The web access may then be through an institutional gateway. The system is called Hyper-V PCs and has multiple physical servers that are formed into a cluster. The cluster may have dozens of PCs connected. Students may access the virtual network through the connection to a webpage configured as a gateway to the computing or access environment. The infrastructure has multiple network elements, including the Hyper-V database, various sequencers, VDI Hosts, VDI connection broker, VDI Web Access terminal or server, an Active Directory (AD), and users. They query the infrastructure via a VDI host accessed through a dedicated webpage. Once the user is successfully identified, he or she is allocated a dynamic address from the Active Directory. They use that address throughout an online or logged-in session.
As soon as the user detaches from the network, the server refreshes and marks that particular address as being not occupied. This refreshment scenario is like the typical refreshment in ordinary physical servers. It is being only much quicker and effective because only one address allocation protocol is in use. Various components are virtual making their response time shorter.
The VDI connection broker is mandated with making distributions of various users to virtual machines. The host number one is responsible for the protection and routing of all IP addresses when users wish to connect to the VN. Meanwhile the Host 2 is responsible for management of programs for users to access via the web access terminal. The two sequencers are responsible for the conversion of applications into virtual outputs or packages that can be run on either Windows 7 or Windows XP depending on the particular sequencer. The Active Directory terminal hosts a complete list of all peripheral and virtual devices connected to the network. It manages their generic and dynamic addresses at any one time the network is in use. The server interface combines the Terminal Server and the Applications server. The latter one is responsible for running the VD applications as well as configuration of a readable package equivalent of applications in the VDI interface. The terminal server does the actual presentation of the application in the Graphical User Interface output.
To illustrate the typical usability of any VDI environment in a class with 76 computers, the combination table below has been plotted. It shows the various data’s transmission rates within a period of three months.
The results show a typical bus speed variation of up to 20Mbps and a maximum network data rate varying between 120Mbps and 410Mbps. The typical students’ download speeds at the beginning of classes can be average 5Mbps, while the maximum individual rates can reach 28 mbps. The various data transfer protocols are interlinked into the same data carrier systems. They ideally compete for bandwidth. However, typical local area networks, the type normally preferred by large institutions, are capable of the very high local data transfer rates. Therefore, the average user is at least likely to experience data transfer rates comparable with other broadband connections, and sometimes even higher. This efficiency is achieved through resource optimization that can be achieved through the VDI systems.
From the foregoing discussion, application of the VDI technology may find a widespread application in modern university settings. Visualizing the typical university setting with about 3500 desktop terminals situated in various locations including libraries, offices, laboratories, and other areas, the software upgrade necessitating the upgrade of all installed hardware may be very cumbersome, time consuming, and expensive. Time within the campus setting may not be available as there are hundreds or thousands of programs and procedures that must run without intervention as well as very key calendar events that should not be postponed. In addition to the existing computer infrastructure which cannot be easily upgraded, the campus administration may require to enable an efficient access to the campus network for all students and staff from various access points while roaming within the institution. This combination of software, hardware and network demands for the institution may be expensive and labor intensive to obtain as well as maintain. For this reason, the VDI infrastructure may be implemented with the following key benefits.
Implementing hardware or software changes to meet a rising demand for faster, more user-friendly and more features packed systems can be expensive. For instance, the campus running 3,000 prices of desktop computers being suddenly declared insufficient in coping with the current user or institutional demands may need to invest millions of dollars in replacing the PCs. It occurs unless to mention a replacement of all associated hardware support devices such as cabling coming with numerous man hours, demolitions, and reconstructions of installation ports and ducts among other inconveniences and costs. Instead, the software upgrade may be done on one terminal, while all other terminals attached to the primary one are connected via a virtual desktop infrastructure (Jaanus, Kukk, & Umbleja, 2010).
As an example, the State University of Michigan began in 2011, a project to implement the VDI interface in its Health Information Technology (HIT) computer systems. They will incorporate the VDI capability to its more than 1,700 desktop computers and eventually to all users within the campuses records (MSU, 2014). The campus installed, in addition to the typical components of the VDI discussed above, the large Storage Area Network (SAN) to host the campus’ huge volumes of files that change hands every day. The administration states that the implementation of the VDI network will reduce the number of servers by 75%. It implies cost saving in terms of energy demands for the servers, space occupied by servers as well as administrative costs for the server environment including the costs. It happens due to the support staff, IT specialists, servicing and maintenance costs, and related costs.
The separation is with respect to a traditional requirement that the tangible CPU has to be coupled with a display unit. The modern technological advancement has made it possible and typical to have lighter and less cumbersome machines performing the same work or even many more activities. It is in comparison with the traditional configuration of the personal computer comprising or a physical CPU, monitor, keyboard, mouse, and printers. The introduction of the VDI enables an end user to access the institution’s computing capabilities through a mere slim display unit with the network access capability. Therefore, students using tablets should be able to access the campus’ resources via a web Uniform Resource Locator (URL). It links them with the campus’ VDI network. Yet, those using physical terminals will also be able to access the network resources through the same access channel. It makes easier and more comfortable to utilize available institutional resources. In addition, it is true to observe that campuses today have a bigger students’ enrollment, especially owing to the global trend of online or long distance e-learning. Future campuses may have a bigger percentage of their students accessing learning resources online, at least, in the process of the course duration. Moreover, an increasing usability of technology for learning and research will make the reliance by large institutions on some traditional computing arrangements as rather difficult and inefficient. Thus, VDI is a handy tool for a mobile user who cannot afford staying on one place. It fits also an institution that wants to optimize learning outcomes regardless of the physical space availability or the physical presence of an end user or learner.
Maintenance and security are the next major reasons why VDI will benefit the university learning and administrative incentives. Physical computing infrastructure is liable to a frequent failure, necessitating periodic maintenance activities. The later ones consume time, money, and lead to some downtimes in a service delivery. Thus, the fewer there are physical devices being essential for the network operations the more efficient the whole system becomes. In essence, VDI systems are mainly just software applications, requiring the minimal physical hardware for support and implementation. Thus, the use of VDI can greatly implement cost leadership into institutions where annual budgets are regulated and tuned for the maximum efficiency. Security is another key reason for the implementation of VDI networks. Here, it mainly implies security against a file loss or manipulation. It is due to the fact that most files are located in the VDI’s storage servers being housed within a storage centre. They are subject to a minimal and authorized access. Thus, important file backups can be carried with an optimal supervision, as contrasted with some cases where the individual staff at departments is mandated with the file management and maintenance. In addition, network attacks typical in Internet connected user terminals can be centrally done by the administration. Thus, it is going to prevent an occasional security compromise owing to user oversight, recklessness, or incompetence.
There is, however, a downside to the implementation of VDI systems. Firstly, it requires a very strong storage, bandwidth, and servers. These three elements are extremely essential for the VDI concept to do so much as just work. These elements are very expensive, though not as cost worthy as a collective infrastructure for physical clusters of hardware being replaced. However, it is certainly an expensive initial investment. It is true that VDI systems may reduce the rate of hardware and software related failures. Anyway, it certainly does not completely eliminate the likelihood of system hitches. It reduces a number of items in the network that need a frequent maintenance and, therefore, maintenance costs. However, the failure of a component in the VDI system is likely to be more catastrophic for the entire network than a failure of the component in an ordinary network infrastructure. Considering the VDI network illustrated above, it is easy to see that all the components within it are unique and essential. None of the components performs the work of another, or has its role duplicated with any other component. If an Active Directory fails, for instance, it can be safely expected that the entire network may fail due to addressing protocol irregularities. If a web access server fails, none of users accessing the VDI system virtually would be able to secure a login into the system. It is due to the fact that the login is done via a webpage locally hosted in the network’s server. In contrast, typical networks using the physical hardware normally have fragmented network components, including access points established via multiple routers. Thus, the failure of one domain name server or any access point is easier to deal with by using other network nodes with similar functionalities. Within a VDI environment, the replication of network components may not only be very expensive, but may also introduce complexities in the virtual environment. It may render the network inefficient. The repair and maintenance of components in the VDI system may be more costly per incident than random repair costs in the ordinary network infrastructure per an incident. It is because VDI components almost always require the dedicated and skilled professionals, while the ordinary network maintenance could be conducted by the staff with basic network maintenance skills.
Another important consideration is that VDI is typically arranged like a ring network where the failure of just one network node stops the entire network. Such a moment may mean unfathomable losses for the institutions running vital programs. For instance, if connected to vital live environments including sensitive processes, the health center VD infrastructure at the State University of Michigan may take irreparable losses. It happens in case if one key component in the network fails.
The other challenge in the implementation of VDI occurs concerning licensing. The VDI environment is based on a complex interplay of hardware and software systems being from different manufacturers. They are subject to usage licensing that may become violated in events of the virtual environment implementation. Thus, the VDI administration will be required by the application for new license types. It is a process that may potentially slow down the implementation and increase costs.
The Virtual Desktop Infrastructure as an alternative to ordinary networks at universities is a good technological concept. Nowadays, it is gaining a high popularity. The concept is likely to get a widespread application due to the emerging network and traffic challenges at medium and large institutions where software and hardware upgrades could be very expensive. In addition, the limited physical space for hardware installations are forcing institutions to drop the conventional, bulky, and space consuming hardware in favor of virtual computing installations. The latter ones not only reduce the space needed for such installations, but can also use machines installed elsewhere remotely. Lastly, the VDI environments help institutions provide a seamless and high speed work as well as study environments for the staff and students. It will enable universities to achieve a better staff’s and students’ productivity as well as allow users to access resources from different environments. Thus, it will save their time and money.
VDI infrastructures are likely to experience multiple licensing requirements before a start-up. This factor may delay the usability. In addition, a component failure in a VDI setting is likely to lead to more severe work interruptions as well as trigger more losses. However, both factors are likely to be easier solved as the VDI technology implementation advances. In any case, the benefits of this technology outweigh the losses. The VDI is, therefore, the technology, the time of which to be enabled has come.