CCNA4. Design and support of computer networks

The goal of this course is to help develop the skills required to design small corporate LANs and WANs. The course is a short tutorial on gathering information about customer requirements, choosing equipment and protocols based on those requirements, and creating a network topology to meet customer needs. Issues related to the creation and implementation of the proposed project for the client are also considered. The course aims to develop the practical skills required to work as Presales and Entry-Level Networking Professionals.

Upon completion of this course, you will receive information on the following topics: cisco wireless certified

the goal of proper network design;

Using the Cisco Network Lifecycle Method in Design;

methods of describing existing networks to prepare for their modernization;

the impact of various applications and services on network design;

requirements for the design of the central level, distribution and access levels for the enterprise complex, including wireless access and security;

design requirements for WAN connections at the enterprise edge and VPN support for remote workers;

testing and verification of the design of the network of the enterprise campus and the global network;

preparation and presentation to the client of a commercial proposal for network modernization.

An introduction to the concept of network design. Basics of network design. Design analysis at a central level. Analysis of distribution level issues. Analysis of design issues at the access level. Analysis of server farms and their protection. Analyze wireless network issues. Support for WAN and remote workers.

Determine network requirements. Implementing Cisco Lifecycle Services. Explanation of the sales process. Preparation for design. Determination of technical requirements and limitations. Define the design requirements for manageability.

Description of the existing network. Documenting the properties of an existing network. Upgrading an existing Cisco IOS OS. Modernization of existing equipment. Survey of the wireless area. Documenting the requirements for the network design.

Determine the impact of applications on the network design. Description of network applications. Basic network applications. Implementation of quality of service (QoS service). Analysis of voice and video capabilities. Traffic and application streams recording.

Network project creation. Requirements analysis. Choosing a suitable LAN topology. Designing WAN and remote worker support. Design of wireless networks. Enabling protective equipment.

Using IP addressing in the network design. Creation of an appropriate IP addressing project. Create an IP addressing and naming scheme. Description of IPv4 and IPv6.

Creation of a network prototype for a complex of buildings. Prototyping to validate the project. Prototyping for LAN. Prototyping a server farm.

Tests on a prototype WAN network. Testing a remote connection on a prototype. Testing WAN connectivity on a prototype. Testing support for remote workers on a prototype network.

How does fiber optics compare to electrical cables?

There are some technical areas, such as optical data transmission, where optical fibers compete with electrical cables, and there are other areas where fiber optic cables have significant advantages : How do fiber optics work

Optical cables are much lighter

Fiber capacity for data transmission is an order of magnitude higher

Signal attenuation can be very low

A large number of channels can be re-amplified in a single fiber amplifier

Fiber optic data transmission is difficult to intercept and manipulate, providing greater security

Fiber optic connections are immune to EMP

Fibers do not pose a fire hazard

However, fibers have disadvantages:

Optical connections are sensitive and difficult to handle. Alignment must be accurate and optimum cleanliness is required.

The fiberglass must remain relatively straight to prevent loss or breakage.

Overall, it is clear that the advantages outweigh the disadvantages, making fiber optics a remarkable innovation.

What are fiber optics used for?

We don't understand how ubiquitous fiber optic cables have become. The laser signals transmitted over these cables are hidden under the sidewalk and even under the ocean floor. The technologies that use these cables are as varied as the light signals themselves.

Computer networks

Fiber optic cables mainly carry information over long distances. This creates optimal conditions for data transfer. Fiber optic cables have many advantages over older styles of electronic transmission:

Less signal loss. Information travels 10 times further before it needs amplification

No interference. Fiber optic cables are less susceptible to electromagnetic interference

Higher throughput. Fiber optic cables carry much more data than older cables of the same size

Computers were once connected over long distances using telephone lines or Ethernet cables, but fiber optic cables have replaced these options because network computers with fiber optic cables are affordable, reliable, secure, and offer higher capacity.

Television and radio broadcasting

While early television and radio signals used electromagnetic waves to transmit signals, cable television companies moved forward using coaxial cables, which carried several analog television signals. As the number of cable TV consumers grew and television networks began to offer more channels and programs, cable operators switched from coaxial cables to optical fibers, from analogue to digital broadcasting.

Medical devices

Medical devices that help doctors look into human bodies without cutting them open were the first applications of fiber optics over 50 years ago. Gastroscopes and arthroscopes are commonplace in medicine today, and fiber optics continues to be an important component in new medical scanning and diagnostic devices.

Military use

Fiber optic cables are cheap, lightweight, high performance, thin, attack-resistant, and very secure. Thus, they provide an easy way to link military bases to missile launch sites and tracking radars. They do not emit electromagnetic radiation easily detectable by the enemy, and they are resistant when subjected to electromagnetic interference.

The relatively light weight of fiber optic cables compared to traditional wires is another advantage. Tanks, military aircraft, and helicopters began switching from metal cables to fiber optic cables. The savings in weight and cost are a big advantage, but fiber optics also increase reliability - their very nature makes them immune to electromagnetic pulse or other interference

We are building a Tier 3 data center using Cisco technologies

In order to get the maximum benefit from the investment, we decided to place our data centers in two highly secure colocation centers in Prague instead of building our own premises. It is a Tier 3 device with 99.982% uptime, which represents an interruption of 1.6 hours per year, and with N + 1 redundancy providing protection against power failure for 72 hours. 

Tier 3 is the highest level of infrastructure available in the Czech Republic. Customers can choose whether they want to use one or both of our data centers. For example, they can place a production environment in one and a disaster recovery backup in the other, or simply place everything in one location. In any case, they will receive highly available IaaS fully managed by Cloud4com with lightning-fast disaster recovery. 

From the very beginning, we have built our data center infrastructure on Cisco Unified Computing System (UCS) server technology, which is based on the standard Intel x86 architecture and supports both virtual and physical machines. Most importantly, the UCS system has allowed us to use blade servers that we can connect, disconnect and replace during full operation without downtime. 

Launched in 2009 when we launched Cloud4com, the Cisco UCS technology was only two years old, so it was still hot news. Many of our customers demanded its benefits, but without the cost of ownership. But we did not use the price as a differentiator. While renting UCS as part of the IaaS cloud services package cost less, the real advantage of our product was the features of the infrastructure itself, which offered both high availability and a higher level of security ccie data center salary. 

We work with Cisco to build trust

To reassure potential customers, we have emphasized the fact that we own the physical infrastructure and thus guarantee security ourselves. No one outside Cloud4com has access to our customers' cloud applications and data. This reassured especially IT managers who were still afraid of spying from times past. 

However, our partnership with Cisco is not limited to UCS. We recently upgraded the switches by moving from the Cisco Nexus 5000 Series to the 9000 Series, increasing throughput to 400 Gbps tenfold. We also use Cisco ASR 1000 aggregation routers to aggregate and encrypt network traffic, CSR 1000V cloud service routers to connect customers to our cloud, and Cisco ASA adaptive security devices for firewalls and network security applications. 

We operate almost exclusively on Cisco technologies and are one of its largest customers in the country. We used its technology to educate the Czech IT community and taught it to perceive and appreciate the benefits of cloud technologies and IaaS. To build a successful and scalable cloud IaaS solution, for us it meant to automate every process that is possible and to actively monitor the occurrence of events in the system and its use in real time. In this regard, Cisco's strategy has been a key factor in our success. Its approach is to ensure the availability and control of technologies in a software way, through well-defined APIs. This ensures consistency and speed of service delivery and high availability. It also allows us to provide customers with contractual guarantees of parameters while maintaining the economy of operation. 

In the last five years, we can observe an increase in demand for cloud technologies and IaaS among medium-sized companies. IT and CFOs come to taste the idea of ​​infrastructure as a regular monthly expense, similar to electricity or software licenses. 

Although this shift in attitudes partially stimulated the arrival of cloud services by Amazon and Microsoft, we are still considered a leader and pioneer in the field of IaaS in the Czech Republic.

The Role of the Computer Analyst

The role of the computer analyst is to assess the computer and technical needs of the users of a given computer system as well as the evaluation and implementation of these systems. It coordinates, therefore, the implementation of changes related to data in both development and production environments.

The IT analyst works in the service of private or public organization to correct failures in their information systems if they occur and make them more efficient by seeking suitable solutions and ensuring the quality of their applications.

The latter may have to perform functional analyzes, technical analyzes and analyzes of systems that he manages and develops by designing software of all kinds such as office software, programming software, educational software or software. industrial control. As it can tailor software that will meet specific needs.

The IT analyst also designs any other IT tool for developing IT systems. Then, he advises the leaders of the company for which he works or for which he is a missionary, on the optimization and performance of their systems and networks.

This computer enthusiast performs programming when designing software. He advises and communicates strategic orientations relating to information technologies as well as the massive processing of standardized administrative communications.

Main missions: Computer analyst

Designs, develops, evolves IT systems

Carry out studies on digital and data security;

Monitors management processes and designs IT work tools

Proposes business solutions and performs preliminary studies

Performs a functional analysis of technological infrastructures and networks

Coordinate the implementation of data changes in development and production environments

Technical skills

- In-depth knowledge of computer analysis

- Knows how to carry out diagnostics and detect computer faults

- Software design

- Design of IT tools

- Synthesis capacity

- On the lookout for new technologies

- Proficient in English

Personal qualities

- Sense of analysis

- Rigor

- precision

- Adaptability

- Listen

Evaluating and integrating AWS controls

AWS provides a wide range of information about its IT control environment to customers

through technical papers, reports, certifications, and other third-party attestations. This

documentation helps customers to understand the controls in place, relevant to the

AWS services they use, and how those controls have been validated. This information

also helps customers account for and validate that controls in their extended IT

environment are operating effectively solutions architect salary.

Traditionally, internal and/or external auditors validate the design and operational

effectiveness of controls by process walkthroughs and evidence evaluation. This type of 

Amazon Web Services Amazon Web Services: Risk and Compliance direct observation and verification, by the customer or customer’s external auditor, is

generally performed to validate controls in traditional on-premises deployments.

In the case where service providers are used (such as AWS), customers can request

and evaluate third-party attestations and certifications. These attestations and

certifications can help assure the customer of the design and operating effectiveness of

control objective and controls validated by a qualified, independent third party. As a

result, although some controls might be managed by AWS, the control environment can

still be a unified framework where customers can account for and verify that controls are

operating effectively and accelerating the compliance review process.

Third-party attestations and certifications of AWS provide customers with visibility and

independent validation of the control environment. Such attestations and certifications

may help relieve customers of the requirement to perform certain validation work

themselves for their IT environment in the AWS Cloud.

AWS risk and compliance program

AWS has integrated a risk and compliance program throughout the organization. This

program aims to manage risk in all phases of service design and deployment and

continually improve and reassess the organization’s risk-related activities. The

components of the AWS integrated risk and compliance program are discussed in

greater detail in the following sections.

AWS business risk management

AWS has a business risk management (BRM) program that partners with AWS

business units to provide the AWS Board of Directors and AWS senior leadership a

holistic view of key risks across AWS. The BRM program demonstrates independent

risk oversight over AWS functions. Specifically, the BRM program does the following:

• Performs risk assessments and risk monitoring of key AWS functional areas

• Identifies and drives remediation of risks

• Maintains a register of known risks

To drive the remediation of risks, the BRM program reports the results of its efforts, and

escalates where necessary, to directors and vice presidents across the business to inform business decision-making.

How does network analytics benefit from AI/ML techniques?

Network analytics uses a combination of local and cloud-based AI-driven analytics engines to make sense of all collected data. Using AI and ML, network analytics customizes the network baseline for alerts, reducing noise and false positives while enabling IT teams to identify issues, trends, anomalies, and root causes accurately. AI/ML techniques along with crowdsourced data are also used to reduce unknowns and improve the level of certainty in decision making ciso engineer.

Artificial intelligence (AI)

Artificial intelligence simulates intelligent decision making in computers. Many sources confuse artificial intelligence with machine learning (ML); machine learning is a subset of the many types of applications that result from the field of artificial intelligence.

Machine learning (ML)

Use of ML can improve analytics engines. With ML, the parameters in the decision tree can be improved based on experience (cognitive learning), peer comparison (prescriptive learning), or complex mathematical regressions (baselining).

ML offers large increases in the accuracy of insights and remediation, because with it the decision trees are modified to meet the specific conditions of a network's configuration, its installed hardware and software, and its services and applications.

In cases when an analytics engine may not have enough information to unequivocally identify endpoints, it may use ML to group together endpoints with similar characteristics. These clustering algorithms consider the distance between cluster members, density areas of the data space, and other factors when clustering objects, much like a human would. In many cases, the algorithms cluster more consistently and across many more dimensions than would be feasible for a human. Such clusters may be used by administrators to remove ambiguity and profile endpoints accurately.

ML is a subset of AI, since it gives analytics engines the ability to automatically learn and improve from experience without being explicitly programmed.

Machine reasoning (MR)

When analytics engines are programmed to reason through logical steps, MR is achieved. This capability can enable an analytics engine to navigate through a number of complex decisions to solve a problem or a complex query.

With MR, analytics can compare multiple possible outcomes and solve for an optimal result, using the same process that a human would. This is an important complement to ML.

CCNA Routing and Switching. Basics of Switching and Routing

Annotation

The course is intended for students wishing to build a career in the field of information technology, and can also be useful for professionals with work experience and who want to structure their knowledge. The course prepares for passing the CCNA industrial certification in the direction of "Routing and switching".

The methodological support of the course includes built-in interactive and Flash-scripts, videos, test questions that help to consolidate the passed material. The course provides for the use by students of software packages such as Packet Tracer (new version 7.2.1 with IPv6 support), which allow to consolidate theoretical knowledge using practical scenarios, solving configuration problems and finding problems, errors in the settings of the existing network.

The learning space in the new learning environment - Cisco Netacad, is built on the principle of a social network. Many possible forms of communication: forums, chats, allow students to very flexibly exchange information, initiate discussions, both with the instructor and among themselves, creating an environment for effective learning and collective mutual assistance.

Knowledge and skills obtained as a result of training

Upon completion of the proposed program, students should know and be able to: ccnp switching

Select suitable devices (hub, switch or router) according to the requirements of your tasks;

Connect routers and switches according to the requirements of the network infrastructure;

Use Cisco software to identify interfaces, protocols, addresses and obtain status information about a network containing several connected Cisco devices;

Configure switches and routers to support specified services and protocols used on the network;

Configure switches for efficient operation of the Spanning Tree Protocol (STP);

Configure static IP routing tables;

Configure access control lists according to the specified requirements for controlling access to devices and the requirements of network traffic in general;

Configure rules for translation of network addresses using Network Address Translation (NAT) technology;

Check the compliance of routers and switches and their network services with the specified requirements;

Use tools to identify the sources of network faults and resolve them.

Courses in the development of which the acquired knowledge will help

CCNA Routing and Switching. Building scalable networks

Two Major Functions of VLANs

Each virtual switch, or VLAN, is simply a number assigned to each switch port. For example, the two switch ports in the red mini-switch might be assigned to VLAN #10. The two ports in the orange mini-switch might be assigned to VLAN #20. And lastly the two switch ports in the blue mini-switch might be assigned to VLAN #30.

If a port is not explicitly assigned a VLAN number, it resides in the default VLAN, which has a VLAN number of 1.

Traffic arriving on a switch port assigned to VLAN #10 will only ever be forwarded out another switch port that belongs to VLAN #10 – a switch will never allow traffic to cross a VLAN boundary. Again, each VLAN operates as if it were a completely separate physical switch.

In the first illustration, traffic from the red switch cannot magically appear on the orange switch without first passing through a router. Similarly, in the second illustration, traffic in VLAN #10 cannot magically appear on VLAN #20 without also passing through a router.

Each of the VLANs also maintain their own, independent, MAC address table. If Host A sends a frame with a destination MAC address of Host B, that frame would still be flooded solely within the switch ports in VLAN #10.

Ultimately, assigning different ports to different VLANs allows you to re-use a single physical switch for multiple purposes. This is the first major function of a VLAN.

But that isn’t all VLANs allow you to do. The second major function is VLANs allow you to extend the smaller Virtual switches across multiple Physical switches.

Extending Virtual Switches across multiple Physical Switches

To illustrate this point, we will expand the topology above with an additional physical switch and two additional hosts: cisco voip certification

Notice how a VLAN# 10 and VLAN# 30 have been extended onto a second switch. This enables Host A and Host C to exist in the same VLAN, despite being connected to different physical switches located in potentially different areas.

The primary benefit of extending a VLAN to different physical switches is that the Layer 2 topology no longer has to be tied to the Physical Topology. A single VLAN can span across multiple rooms, floors, or office buildings.

Each connected switch port in the topology above is a member of only a single VLAN. This is referred to as an Access port. An Access port is a switch port that is a member of only one VLAN.

When configuring a port as an Access port, the administrator also designates the VLAN number that port is a member of. Whenever the switch receives any traffic on an Access port, it accepts the traffic onto the configured VLAN.

In order to extend a VLAN to the second switch, a connection is made between one Access port on both switches for each VLAN. While functional, this strategy does not scale. Imagine if our topology was using ten VLANs, on a 24 port switch nearly half of the ports would be taken up by the inter-switch links.

Instead, there is a mechanism which allows a single switch port to carry traffic from multiple VLANs. This is referred to as a Trunk port. A Trunk port is a switch port that carries traffic for multiple VLANs.

vlans-trunks-and-accessWe can use Trunk ports to reduce the amount of switch ports required for the topology above. This enables us to leave more ports available to add hosts to the network in the future.

This physical topology operates (logically) identically to the illustration above it, but requires far fewer switch ports.

We were able to use a total of four Trunk ports (across both switches) to replace eight different Access ports in the prior illustration.

Typically, switch ports connected to end-host devices are configured as Access ports (e.g., workstations, printers, servers). Conversely, switch ports connected to other network devices are configured as Trunk ports (e.g., other switches, routers). We will uncover the reason for this later in this article.

What are the different types of service companies?

Thanks to the evolution of society, lifestyles and work and technologies, many types of services are now sought after in the market. As a result, there are as many service companies as there are services. However, in France, service companies are distinguished according to 3 main categories: Engineering Freelance

companies providing services to individuals;

service companies with mixed activities.

Business services companies

The services provided to companies are provided for by the French Nomenclature d'Activity 2nd revision of the national institute for statistics and economic studies or Insee. The specific activities of business services companies are provided for by sections M and N of the nomenclature, namely:

activities related to legal affairs, accounting, management, architecture, engineering, technical control and technical analyzes;

scientific research and scientific development activities;

advertising and market research activities;

veterinary activities;

design, translation and interpretation, photography activities;

activities relating to rental and leasing;

activities related to employment;

activities specific to travel agencies;

activities relating to building and landscaping;

support services and administrative activities.

Companies providing services to individuals

The services provided to individuals are provided for by the French Nomenclature of Activities 2nd revision of the National Institute of Statistics and Economic Studies. To this end, the specific activities of companies providing services to individuals or companies providing services to individuals are provided for by sections R and S of the nomenclature, namely:

activities related to entertainment and recreational activities;

activities related to art;

activities linked to the repair of personal movable or immovable property, for example IT service companies.

Service companies with mixed activities

Mixed activities can be defined by the accumulation of two distinct or linked activities. In the case of two activities linked together by their nature, the second activity is an extension of the first. By way of illustration, it is possible to take the example of a mechanic who sells car parts and who installs them on the vehicle to be repaired.

In the case of two completely distinct activities, it is necessary for the service company to detail the nature of its activities in the corporate object.

What status to create yours?

The service company is a company like any other from the point of view of corporate legal status . In this sense, there is no specific legal status for service companies. Indeed, they can take over the usual legal statutes such as SARL or SAS . The only criterion that differentiates them is at the level of the activities carried out. However, to establish yourself as a service provider, it is preferable to adopt an individual and one-person form, that is to say:

set up as a sole proprietorship;

set up as a sole proprietorship with limited liability or EIRL ;

set up as a single-member simplified joint stock company or SASU .

The status of sole proprietorship

The legal status of sole proprietorship implies that there is no distinction between the personal assets and the professional assets of the service provider.

At the level of the social system, the service provider established as a sole proprietorship benefits from membership in the self-employed workers' scheme.

Finally, with regard to the tax system, the service provider established as a sole proprietorship benefits from income tax.

Responsibilities of data engineers

The clients who rely on data engineers are as diverse as the skills and outputs of the data engineer teams themselves. No matter what field you work in, your clients will always determine what problems you solve for them and how you solve them.

Here, through the prism of data needs, we list several typical customer groups: what is IT?

Data Science and AI Teams;

Business intelligence or analytics teams;

Product teams.

Before any of these commands can work effectively, the data must meet certain requirements and provide:

Confident transition to broader analytics systems;

Be available to all participants in the processing and research processes.

These requirements are detailed in Monica Rogarty's excellent article “The AI ​​Hierarchy of Needs". As a data scientist, you are responsible for meeting your customers' needs for quality data. However, you will use different approaches to meet the individual requirements of your data mining workflow.

Data stream

To do anything with data on the system, you must first ensure that it can enter and pass through the system securely. Input data can be almost any data type that you can imagine, for example:

Data engineers are often responsible for using this data, designing a system that can take this data as input from one or more sources, transform it, and then store it for their clients. These systems are often referred to as ETL pipelines એ which stands for extract , transform, and load .

Responsibility for the data flow is mainly in the extraction phase . But the data engineer’s responsibility is not limited to loading them into the pipeline. They must ensure that the pipeline is robust enough to withstand unexpected or corrupted data, disconnection of sources on fatal errors. Uptime is very important, especially when you are using real-time data or data that is time dependent.

Your responsibility to maintain the flow of data is constant and independent of who your client is. However, some clients can be more demanding than others, especially when the client is an application that relies solely on real-time data.

Software Web Developer, Senior Software Developer

A web software developer or senior web software developer is someone who has professional programming experience. They can be distinguished through his ability

write complex code

understand databases, application services, and application lifecycle development

mastery in building entire applications.

Most of a software development career will include several years of work as a senior web developer.

People who don't like the idea of ​​management and who prefer to write code can spend many years or even their entire career as a senior web developer.

Computer science vs software engineering

Lead Software Engineer

For someone looking to take on additional responsibilities and a more challenging role, a Lead Software Engineer or Architect might be the right fit.

Lead Software Engineers supervise other engineers and programmers, and this role is seen as a mid-level management position. However, top software engineers still write code, but also collaborate with others to prioritize workflow and implement final decisions. They have years of experience in specific programming.

Technical architect

Technical architects still write code from time to time, however, they are primarily responsible for developing complex systems that other web developers will execute. The role of an architect is very technical.

Development Team Leader, Software Development Manager

As a development team leader or software development manager, your responsibility is to manage development teams, large-scale projects, and hire and fire developers.

Middle managers monitor the performance and workflow in the department and report to the senior manager. The senior manager, in turn, coordinates the project manager's needs with the development team, which requires remarkable people skills and the ability to effectively resolve conflicts.

Director, Vice President, Chief Technology Officer

Senior management, such as director, vice president, and CTO, reports to the CEO or board of directors of the company. They direct the work of other managers and are often responsible for setting strategic and corporate direction.

If people management isn't what you're interested in, a career as a software engineer still provides such a good level of income that you can still be a team player and have a decent career.

Software engineer

According to the US Bureau of Labor Statistics, the outlook for engineers and software developers is 24% growth, much faster than the national average for jobs. Due to the high technical qualifications and the small number of qualified engineers, the stakes are high for a software career.

Network administrator

A network administrator is a person responsible for managing the computer network. It manages, among other things, workstations, user accounts, Internet connectivity including routers, modems, firewalls and virtual private networks (VPN).

Main tasks

The common tasks of the network administrator are the management of the network cabling (physical connection between several machines), the management of the routing (logical connection between the inside and the outside of the network or between several subnets), the management of security (antiviral protection, firewall, intrusion prevention, etc.) and management of user access rights (network access, etc.).

Training

Ideally, a network administrator will have a college diploma (DEC) or a bachelor's degree (BAC) in computer science. It is also recommended to update your knowledge by following specific training.

Skills

The network administrator must have: highest paying jobs

good general computer skills: Internet connectivity, communication protocols, operating systems, office software, computer hardware;

good knowledge of computer security (antivirus, firewall, intrusion tests, etc.);

A good sense of resourcefulness and organization;

A mad passion for solving technical problems and implementing procedures to improve the efficiency of networks.

Salary

If you were hesitant until now about becoming a network administrator, stop! You can butter your bread and potatoes in the oven everyday.

Statistics Canada indicates that the average hourly wage is between $ 17.33 and $ 47.26, for an average of $ 31.00.

Regarding Emploi Québec, it is more or less the same thing. The minimum wage is $ 17.20 an hour and the maximum is $ 46.15.

And employment prospects are "good" according to Statistics Canada and Emploi Quebec.

Elements of the WLAN architecture

The list of core elements includes basic service kits, portals, and a distribution system. The structure and content of the functions performed by the listed elements is as follows.

1. Basic Service Sets (BSS) are wireless LAN components that allow their nodes to communicate with each other and with other LAN nodes by transmitting signals using electromagnetic waves. The structural constituent parts of the BSS are stations (Station - STA) and access points (Access Point - AP).

BSSs are a collection of network nodes and wireless network adapters. A host is any device that is a source of packet messages (computer, digital telephone, etc.). WNIC provides reception and transmission of radio signals (PHY-layer), as well as the functions of a MAC-layer controller. In general, the term “station” in relation to a collection of a node and a WNIC corresponds to the analogous concept stipulated by the Radio Regulations - it is a collection of receivers and transmitters, including additional devices necessary to perform the functions of a radiocommunication service.

An access point (AP) is an entity with STA properties that performs two functions: coordinating the access of BSSs to the common wireless environment and access of BSSs to the distribution system.

The need to coordinate the work of BSS stations is due to their use of a common frequency-territorial resource. The area within which communication between BSSs is provided is called the Basic Service Area (BSA). The weight of BSSs shares one common frequency band for radio signal exchange, and collisions between radio signals of different stations result in harmful mutual interference, which precludes the possibility of simultaneous communication of several stations. Communication between BSS stations is carried out in half-duplex mode with signal relay (similar to radio relay communication) of different STA access points. The set of functions performed by the STA and AP to ensure the transmission of messages within the BSS is called the Station Service (SS).

Access points are the infrastructure elements of the BSS; they are used in all premises (basic service areas) that are designed for continuous WLAN operation (in particular hot spots). As infrastructure elements, APs provide an interface between the BSS and the LAN distribution system. In case the BSS is autonomous, the access point can provide direct access to the backbone network (Internet). For this purpose, industrial designs of AP are equipped with a router.

2. A Distribution System (DS) is a network element that transfers messages between different BSSs, as well as between the BSS and the wired LANs in the network. The medium that allows messaging between network segments (wired and wireless) is called Distribution System Medium (DSM). The set of functions performed by DS is referred to as the distribution system service. (Distribution System Service - DSS). Station Services (SS) and DSS together provide the ability to transfer messages between STAs belonging to different LAN segments. An essential feature of message transmission via DS is that the transmission protocols are MAC-layer protocols, so that stations of different BSSs and wire segments communicate with each other without going beyond this layer.

The digital network distribution system environment that is located inside buildings is generally wired. The distribution environment for LANs that span segments that are dispersed across an open facility (such as a campus or office) can be wireless. The IEEE 802.11 standard does not impose restrictions on how DSM is implemented, nor on the list of functions of the ISO / OSI protocol stack that an environment can perform. In particular, these functions can go beyond the 2nd (link) layer and cover the 3rd (network) layer. The latter corresponds to the interconnection of LAN with wide area networks (WAN), in particular, the Internet (in this case, a router). The creation of an interface between DS and WAN corresponds to one of the most common uses of Wi-Fi - WLAN - the creation of hotspots. Under the IEEE 802.11 protocol, the relationship between WLAN and WAN is not regulated.

3. Portals are network elements through which wired network segments are connected to the Distribution System (DS), operating in accordance with the requirements of wired LAN standards (for example, 802.3 - Ethernet). Through portals, messages are transmitted between wireless and wired network segments according to MAC-level protocols. Connecting wired segment nodes to DS using portals is called network integration . Due to the transfer of messages according to the protocols of the same layer (MAC-layer), the nodes of all network segments, wired and wireless, are logically equal.

The collection of all BSS networks and integrated wired segments (local area networks) is referred to as the Extended Service Set (ESS). The area occupied by ESS elements is referred to as the Extended Service Area (ESA). The maximum number of ESS nodes is not regulated by the IEEE 802.11 standard. ESS infrastructure: its distribution system, access points, portals, interface with the WAN - is created by the operator (provider) of the ESS. The network provides, firstly, the interconnection between all nodes included in the wired and wireless segments, and, secondly, the connection with the nodes of the global network (if such communication is provided).

The unambiguity of identification of network nodes during the transmission of messages between them is ensured by the adopted system of code designation of network elements. There are 3 types of element identifiers: wlan definition

- ESS identifier (Service Set Identifier - SSID), which is an ESS name, consisting of 32 alphanumeric characters;

- BSS identifier (Basic Service Set Identifier - BSSID), which matches the MAC address of the access point of the corresponding BSS;

- STA identifier , which coincides with the MAC address of the station under consideration.

The MAC addresses are assigned to the AP and STA in accordance with generally accepted rules: the first three bytes of the address are used to designate the NIC manufacturer, and the remaining three are used to designate the NIC number. Network identifiers (SSIDs) are defined by their operators and are usually a textual "network name". All ESS stations must have the right to use its telecommunication resources. SSIDs are used for the initial (initial) verification of the subscribers' eligibility to work in the ESS.

What is fiber optic

Glass fiber is a construction material with many properties. We use them to transport data as quickly as possible. With this new technology, internet speed has reached a whole new level. Up to 300 Mbit / s are currently possible for downloading and uploading. In the case of fiber optic networks, data rates from gigabits to terabits per second can theoretically be achieved - regardless of the distance. Other current broadband technologies such as cellular communications / LTE or television cable are nowhere near the performance of a fiber optic infrastructure.

Define fiber: Optical fiber - fiber optic

In the case of fiber optic connections, data is not transmitted by means of electricity , but by light pulses. Fiber optic cables (LWL) are cables made up of fiber optics and partially assembled with connectors for the transmission of light . The light is guided in fibers made of plastic (polymer optical fibers = POF) - glass fibers. Usually several optical fibers are bundled in the cables.

What is a fiber optic connection?

Fiber optic cables are blown into empty tubes that go into the building. These are also known as feeders, drops or microtubes . Empty tubes always go from the house connection to a fiber distributor and from there to a local control center, the so-called Point of Presence (= PoP). From there it goes over the backbone (= main connection of the provider) to the next large Internet hub.

Need for a fiber optic connection for a house

advantages

Fiber optic connections are not only faster , they are also demonstrably less prone to failure .

Unlike in the past, the copper cable is no longer needed on the “last mile” and is being replaced by glass fibers. Then one speaks of the fiber optic FTTB (Fiber to the Building) technology - every house receives a direct fiber optic line.

From a physical point of view, optical waveguides are dielectric waveguides. They are made up of concentric layers: in the center is the light-guiding core, it is surrounded by a cladding with a slightly lower refractive index and by additional protective layers made of plastic. Depending on the application, the core has a diameter of a few micrometers to over a millimeter.

So far, fiber optic cables have been used as a transmission medium, especially in communications engineering, for wired communication systems. Since glass fibers achieve the highest ranges and transmission rates, they have already replaced electrical transmission on copper cables in many areas.

The possibility of replacing spare parts without the use of industrial technology

It is allowed to clarify the content of the sections, introduce new sections or combine some of them.

It is recommended to provide the following provisions in the TK: what does sow mean

- forecast of the development of requirements for this product for the expected period of its release;

- recommended stages of product modernization, taking into account the forecast of requirements development;

- compliance with the requirements of the countries of intended export, taking into account the forecast of the development of these requirements;

- maintainability characteristics;

- the possibility of replacing spare parts without the use of industrial technology;

- the availability and safety of effective use of products by people with disabilities and elderly citizens (for the relevant products provided for by the legislation of the Russian Federation).

The terms of reference are drawn up in accordance with the general requirements for text design documents according to GOST 2.105-95 (ESKD. General requirements for text documents) on A4 sheets, as a rule, without a frame and a main inscription. The sheet (page) numbers are placed at the top of the sheet above the text.

The values ​​of indicators, norms and requirements are indicated, as a rule, with maximum deviations or maximum and minimum values. If these indicators, norms, requirements are unambiguously regulated by the NTD, the TK should include a link to these documents or their sections, as well as additional requirements that take into account the features of the system being created. If the specific values ​​of indicators, norms and requirements cannot be established in the process of developing TK, a record should be made on the procedure for establishing and agreeing these indicators, norms and requirements: “The final requirement (value) is specified in the process ... and is agreed by the protocol with on the stage".

At any stage of product development, with the consent of the customer and the developer, changes and additions can be made to the TK or a document replacing it that do not violate the conditions for fulfilling the mandatory requirements. Coordination and approval of additions to the TK is carried out in the manner established for the TK itself. Changes to the TK are not allowed to be approved after the product has been submitted for acceptance tests. Registration, accounting and storage of technical specifications and additions to it are carried out in accordance with the requirements of GOST 2.501-88 (ESKD. Rules for accounting and storage).

Another document containing the necessary and sufficient requirements for product development and mutually recognized by the customer and the developer can be used as a TK. In the case of proactive product development, TK (or a document replacing it) is based on the results of product market research, as well as patent research in accordance with GOST R 15.011-96 (SRPP. Patent research. Content and procedure)

It is not allowed to include requirements in the TK that contradict the laws of the Russian Federation and mandatory requirements.

Drawing up a technical assignment (TOR) is a complex and responsible task: many data are not yet known, but how the task will be drawn up can facilitate or complicate subsequent design. It is not for nothing that it is believed that a competent technical specification is half the success in solving a problem, and the time spent on preparing a technical specification is one of the best investments that can be made during the design period.

Information security system implementation

The problem of information security is especially relevant for the modern world. Leakage of confidential information, unauthorized interruption of the production cycle can cause enormous harm to the enterprise. To protect information, ensure the continuity of business processes, a well-built mechanism is required.

The implementation of an information security (IS) system should be given close attention. It is necessary for young companies starting to develop their business and enterprises that have been working on the market for a long time. Often, experienced enterprises need to upgrade the existing information security system, which has lost its relevance.

Features of the information security system

Only a set of measures aimed at protecting information will help make the mechanism effective. The system must be available: firewall network security

Strictly in a certain form, place, time;

To a specific narrow circle of people.

In its modern form, it includes:

Hardware (computers, laptops, communication lines, peripherals);

Software;

Stored data;

Users, service personnel.

Effective implementation of an information security system is possible only if laws, instructions, rules are observed, the professionalism of the security service, the responsibility of company managers and personnel.

There are the following levels of information protection:

Software-technical, includes security mechanisms: shielding, access control, user identification and authentication, logging and auditing, cryptography;

Procedural, includes security measures implemented by people: personnel management, physical protection, responding to violations, maintaining efficiency. Enterprises must approve, practice in practice the necessary actions of personnel;

Administrative, includes measures taken by the company's management to implement security policy: administration decisions aimed at protecting information and resources.

Legislative, includes measures of the legislative level, creating a negative attitude towards violations in this area.

How to build an effective information security system

To implement an effective system, you must:

The choice of technical subsystems is based on risk analysis, including possible damage;

Create an effective management mechanism;

Apply proven principles.

When building a new or modernizing an existing system, it is necessary:

Conduct full diagnostics to assess vulnerability, identify threats. It includes:

Diagnostics;

Description of business processes, IT resources, services;

Analyzes, tests to identify threats, vulnerabilities (GAP analysis, penetration tests);

Analysis of the identified risks.

Design the system:

Develop a concept including policies, procedures, attacker modeling;

Develop models (design, architecture);

Draw up documentation, technical design, economic renewal;

Conduct testing (assembly of the stand).

Implement:

Purchase, install, configure technical components, train users to work;

To put into operation.

Accompany and serve.

Such an important process should be handled by professionals with relevant work experience.

CompTIA A+: Learning to Think Like an IT Pro

“I can’t get on the network,” is another common – and frustrating – issue for end users. Both the cause and the resolution can be one of many – hardware, software, network connections, security issues. Two users could report the same problem and require very different resolutions it certification jobs.

While diagnosing and addressing a network connectivity issue certainly requires understanding hard tech facts, like the difference between TCP and UDP ports and their purposes, there's not a single schematic that tells the whole story to an IT pro doing the work.

Manufacturers build things differently, different device models vary in how they're built and computers can have innate design flaws that cause problems. Approaching network connectivity problems can take a combination of next-gen knowledge and old-fashioned elbow grease to fix. Figuring everything out can take some intuition and some artistry on the part of a help desk pro.  

CompTIA A+ Exam Objective Core 1 (220-1001) 2.0 Networking   

Get Ready to Get CompTIA A+

You have many training options to help you prepare for your CompTIA A+ exam, including self-study materials, virtual labs, videos, online classes and in-person career prep classes. In 2020, CompTIA Tech Career Academy is bringing its IT-Ready Technical Support program to classrooms, so that students get the training they need to earn CompTIA A+ and launch their IT careers on the help desk.

Learn More about the CompTIA Tech Career Academy.

Creative Researching and Knowing Where to Look

No help desk pro has every fact about every computer committed to memory – and not every problem that arises is something you can learn studying for an exam. For instance, if a particular operating system recently received a patch that began to cause conflicts with a software package, that’s a development that no one can really anticipate.

Part of the creative problem solving the help desk does involves identifying what might be going wrong and knowing where to look to find a fix. Knowing which online user community to visit or what YouTube tutorial might hold an answer to an emerging problem is key to implementing the right solution. Help desk technicians need to be resourceful in finding the answers they don’t know off the top of their heads.

CompTIA A+ Exam Objective Core 2 (220-1002) 3.0 Software Troubleshooting and 4.0 Operational Procedure   

CompTIA A+: Learning to Think Like an IT Pro

Whether an IT pro is thinking through the questions an end user is asking, diagnosing an issue or researching a glitch on the fly, these tasks all demand creative thinking as much as they require someone who understands the nuts and bolts of IT.

Tech knowledge is crucial, but it’s knowing what to do with that knowledge that makes IT pros successful. Help desk work can be challenging, but it takes a lot of thinking, and that can mean a lot of fun – and a lot of satisfaction with a job well done.

COMPTIA NETWORK +

New Horizons Hannover offers you a CompTIA-authorized curriculum designed to achieve the recognized CompTIA certificates. The CompTIA training and certification at New Horizons Hannover is the ideal basis for starting or promoting a career in the IT field.

With the sustainable CompTIA training courses and seminars from New Horizons Hanover, you will receive the important basic knowledge for your company.

The Computing Technology Industry Association (CompTIA) is the mouthpiece of the IT industry. The members of the globally active association include IT companies and other industry members from a total of 102 nations. CompTIA's goal is to promote global growth in the IT industry.

One of the most important tasks of CompTIA is the globally standardized training and further education of IT specialists. For this purpose, CompTIA has developed manufacturer-neutral certifications for basic IT knowledge in specialist areas such as PC support, IT security or network administration. The specialty of the certifications: CompTIA is supported by member companies and professionals in the preparation of the content. This ensures that the certifications always comply with the latest industry requirements and standards.

This course is suitable for beginners in the computer support field with a basic knowledge of computer hardware, software and operating systems who want to prepare for the CompTIA Network + exam. The course is also suitable for anyone who wants to improve their knowledge and understanding of network concepts and the skills required to prepare for a career in network support or administration.

The CompTIA Network + certification includes the following topics: average salary for it technician

Basics of network theory, concepts and networking methods

Network data delivery basics

Networking of media, cabling and hardware

Network protocols and OSI

Networking Operating Systems

TCP / IP basics

Network security, including prevention and troubleshooting

Service Technician

Vacancy description 

Responsibilities: a plus certification jobs

Solving of most complex errors in an ACP system.

Execution of preventive maintenance (both electrical and mechanical).

Reporting of executed maintenance activities

Execution of inspections

Analysis of system errors

Replacements of machine spare parts

Reporting of problems and maintenance activities that need attention

Requirements:

Experience of supporting automated systems with a good level of electro-mechanical skills.

Electrical fault-finding and fault-rectification skills, including the replacement and configuration of field devices (inverters, sensors, scanners etc).

Mechanical fault-finding and fault-rectification skills (gearboxes, bearings, sprockets, drives etc).

Read electrical schematics, wiring diagrams.

Skilled in the use of standard electrical test instruments.