Abdalla Siwan

Faculty of Computer Information Technologies and Automation
Department Automation and Telecommunication
TKC-07m

""Research and development of subscriber access networks using xDSL technology""
Scientific adviser: Ph.D Turupalov Viktor Vladimirovich Турупалов Виктор Владимирович
e-mail: siwanabdalla@hotmail.com

Summary

Summary

Contemporary period of development of telecommunications in line with the growing increase in demand for infocomm services. That is on telecommunications services which include automated processing, storage or providing information on request, using computer technology, both on the incoming or outgoing at the end of the connection.

Telecommunication network must pass multi-information (speech, data, video, audio) with the necessary timing of these components in real time [1] and guaranteed quality of service parameters. The simultaneous operation of multiple networks (data, voice, video) does not benefit from an economic point of view.

In this age of network technologies are developing with great speed. Growing computing power, capacity, expanding range of services offered by ISP, all invented new mechanisms networking.

This is aimed at pooling resources and joint work of thousands, millions of users. All urgent need of protection and resource delineation access to them. Unfortunately, often by third parties trying to get (and get) access to confidential information in the intellectual property of companies to network services, or direct their efforts to destroy the efficiency of individual hosts or the entire network.

To secure the resources needed to implement an integrated approach to corporate network security multiservice networks. The proposed solutions before the introduction should be fully (as far as time and facilities) tested in laboratory conditions. This applies not only checks, equipment and software, but also the training of qualified personnel capable of properly with it.

The objective of this work is to analyse the technology offered by Cisco, the realization of complex measures to protect the existing network, creating software tools generate traffic for security checks partial 2 - level.

1. ANALYSIS OF DESIGN

Corporate network - this multiservice data transmission network, operating under a unified administration intended to meet the needs of their own production companies and organizations. Corporate information - this information, unauthorized disclosure or modification which could lead to huge financial losses. Therefore, corporate network - a closed structure with a high degree of protection, access to which is prohibited altogether from the outside or severely restricted, and access to information within it to distinguish between the use of administrative and technical methods.

To ensure the protection of data in corporate networks can be used by various organizational and technical methods (emphasis responsible professionals, the use of access control lists, the use of VPN, etc.). Their combination is called a comprehensive system for protecting information. Corporate network can be presented in the form of "islands of local networks".

Calculation of network traffic projectable

Traffic is calculated separately for each type of service on each network node. Formula (1.1) has the form to calculate:

(1.1)

where k - number of network services;

i-nomer hub;

– expectation of traffic that is generated k-th service on the i-th site

– Data transfer rate (in bits or packets for a moment) - the average bandwidth communication channel, which is sufficient to transfer high-quality traffic k-th services;

– the average duration of treatment for k-th services

Total traffic, which is generated at і-ом node equals:

The load is three directions:

There are 2 methods of calculating and internal pressures Source traffic:

1)      The first method is setting the ratios, which reveal the fate of traffic in each direction:k1 – in the internal network, k2 – to neighbouring nodes, k3 – to other networks. In doing so, there is a correlation:

1)      At each stage of analysis network service, determine what services are internal, which are connected with neighboring nodes, and who - with External networks. One must consider the fate of proprietary information that transmission network (it will be clear after the selection of technology and protocol Transfer).

In the event that there are real-time service with constant loading some bandwidth, then when selecting channels necessarily imperative that the capacity of a channel of communication was no less necessary bandwidth.

В Table 1.1 specifications contained some subscription services

Table 1.1 - Options broadcast traffic Online Services

2 ANALYTICAL REVIEW LOCAL NETWORKS

2.1 Review tehnalogiya networking

хDSL — a family of technologies to significantly expand bandwidth the ability of local telephone subscriber line network by using effective linear codes and adaptive techniques for correcting distortions line the basis of modern achievements of microelectronics and digital processing techniques signal.

XDSL services designed to address certain objectives: they should work on existing telephone lines, they should not hinder the work of various equipment subscriber, such as telephone, fax, etc., speed work should be above the theoretical limit of 56 kilobits per second. and finally, they must ensure continuously connected.

The main types of xDSL include ADSL, HDSL, R-ADSL, SDSL and VDSL. All these technologies offer high-speed access to digital subscriber telephone line. Existing xDSL technology designed to achieve certain goals and meet the specific needs of the market. Some are original xDSL technology development, while others are merely theoretical models, while the third had already become widely used standards. An important difference between these technologies modulation techniques are used to encode data.

DSL Technology:

ADSL (Asymmetric Digital Subscriber Line — asymmetric digital subscriber line): version of DSL, which allows the user to transmit data at speeds up to 8 Mbps, and from the user at speeds up to1 Мбит/с.

ADSL2+: version of DSL, which allows the user to transmit data at speeds up to 24 Mbps, and from the user at speeds up to 3.5 Мбит/с.

R-ADSL (Rate-Adaptive Digital Subscriber Line — digital subscriber line connection speeds of adaptation) provides the same speed data transfer that technology and ADSL, but it allows the transfer speed to adapt to the length and used as twisted pair cables. Using technology R-ADSL connection at different telephone lines will have different speed data transmission. The speed of data transmission may be chosen synchronization with the line, while connections or signals from the station.

DDSL (DDS Digital Subscriber Line — digital subscriber line DDS): version of broadband DSL, providing access to Frame Relay technology transfer data at speeds from 9.6 kbit / s to 768 Кбит/с.

ADSL G.lite, or ADSL Lite - version of ADSL, as having an asymmetrical transfer mode with a capacity up to 1536 Mbps from the network to the user, and at speeds up to 384 kbit / s from the user to the network. Well balanced transfer mode at speeds up to 384 kbps in both directions of transmission. He is the ITU-T standard.

CDSL (Consumer Digital Subscriber Line) technology is DSL, developed by Rockwell Semiconductor Systems, which practically is the first version of ADSL G. Lite.

IDSL ( digital subscriber line ISDN) — inexpensive and tested technology, which uses chips digital subscriber line access main BRI ISDN and providing subscriber access with constant speed 144 kbps in both directions.

HDSL (High Speed Digital Subscriber Line — high-speed digital subscriber line): x DSL option with a higher speed of transmission, which allows you to arrange the transfer at speeds bolee1, 5 Mbps (USA standard T1), or more than 2 Mbps (E1 European standard) in both directions, usually for two copper pairs

HDSL2 constitutes an improved version of technology HDSL, having the same function as the usual technology HDSL, while using only one for a couple of telephone cable.

SDSL (Simple Digital Subscriber Line — symmetrical high-speed digital subscriber line, working on one pair); known two modifications of this equipment: MSDSL (multi SDSL) and HDSL2, with built-in mechanism to adapt to the speed of transmission lines physical parameters.

VDSL (Very High Speed Digital Subscriber Line — sverhvysokoskorostnaya digital subscriber line): x technology DSL, which provides data transfer speed to the user to 52 Mbps

ReachDSL is the company's proprietary technology Paradyne, belongs to the group of symmetrical technology and was designed for use on long and substandard subscriber lines. Since it can transmit data at speeds up to 2.2 Mbps in both directions to a distance of not less than 9 km retransmission without equipment. The advantages of new technology is to expand the radius of service compared with ADSL (~ 3,9 km), less exposure to outside influences or fire (~ 15 dB decade), much smaller line losses. In addition, become less visible branches unplugged cable, radio frequency interference. Due to the fact that ReachDSL works in the low range of common energy costs of equipment technology to support ReachDSL significantly lower than with any other technology DSL. In many cases, ReachDSL used as part of the strategy using ADSL for short subscriber lines, and ReachDSL - for complex and long lines.

ADSL2 и ADSL2+ modifications are "classical" technology ADSL. They were developed taking into account the increased requirements of providers and end users. In ADSL2 and ADSL 2 +, with virtually the same transmission range as ADSL, the speed increased to 12 and 25 Mbps respectively. In addition, realized the change of speed adaptive function. Thanks to these changes became possible support many new applications and additional services (video, multimedia, etc.).

2.1.1 Ethernet Technology

Ethernet technology has recently ceased to be the only technology that is used in the construction of local (vnutriobektovyh) networks. The current level of technology encompasses network LAN, WAN and MAN. Modern technology provides Ethernet work at high speeds 1 Gbit / s, 10 Gb / s, using optical fibers, direct access to primary network connection, the interaction of technology with other technologies Ethernet access network (for example, DSL) and the primary network (for example, SDH , WDM). ТIp Ethernet interfaces are standardized standard IEEE 802.3 (including additions) are divided as shown in Figure 2.1.

Рисунок 2.1 - Типы интерфейсов Ethernet.

The main building Ethernet network topology shown in Figure 2.2

Figure 2.2 - Varieties topology Ethernet.

Possible other options for building a network topology, such as dual ring or point-to-point.

100BASE-X (IEEE 802.3 раздел 21; 24; IEEE 802.3u)
- The speed of data transmission 100 Мбит/с
- Wednesday proliferation signal - obvity pairs fifth category neekranirovanny, 150 ohms, shielded obvity pairs, optical fiber
- Maximum network motifs 100 metres for a pair obvitogo
- Maximum network motifs with two transponders to 200 m Obvitogo pair
- Maximum motifs network with one transponder for 300 m Optical fiber
- Maximum motifs network of 400 m for Half of the regime of optical fiber and 2000 metres for a full regime of work on Optical fiber.
- Type encoding 4В/5В; NRZI

100BASE-ТX (IEEE 802.3 раздел 21; 25; ИЕЕЕ 802.3u)
- The speed of data transmission 100 Мбит/с
- Wednesday proliferation signal - obvity pairs fifth category (shielded Or not) 100 Ом
-- Maximum motifs segment 100 m
-- The type of encryption 4B5B; NRZI

100BASE-T4 (IEEE 802.3 раздел 21; 23;IEEE 802.3u)
-- Data transfer speed 100 Mbps
-- Wednesday proliferation signal - obvity pairs of third, fourth or fifth category неекрановані100 Om
- Maximum motifs segment 100 м

100BASE-FX (IEEE 802.3 раздел 21; 26; IEEE 802.3u)
-- Data transfer speed 100 Mbps
-- Wednesday proliferation signal - optical fiber
-- The type of encryption 4B5B; NRZI
-- Maximum motifs segment 412 m
-- Maximum network motifs 2 km in a full mode
-- Maximum motifs network for 100 km single fiber in a full treatment
1000BASE-LX (IEEE 802.3 раздел 34; 36; 37; 38 IEEE 802.3z)
- IEEE Tip encoding 8 V10V; NRZI
- The main characteristics of the transmitter (fully defined in the IEEE 802.3 Section 38).
Maximum motifs segment 5000 m on a fiber-optic cable. The range of wavelengths from 1270 to 1355 nm.

 
1000BASE-СX (IEEE 802.3 section 34; 36; 37; 39 IEEE 802.3z)
-- The type of encryption 8 V10V; NRZI
-- Wednesday proliferation signal - shielded pairs tons fifth obvity Category
-- The rate of transmission of signals MBod 1250 ± 125 Bod (full parameters at the exit signal transmitter and receiver are at the entrance to IEEE 802.3 section 39)
- Type encoding 8 V10V; NRZI

 
1000BASE-Т (ИЕЕЕ 802.3 section 34; 36; 37; 39 IEEE 802.3z)
-- The speed of data transfer 1000 Mbps
-- Wednesday proliferation signal - obvity pairs fifth category
-- Bit error ratio (BER bit error rate) is not worse than 10-10
-- The maximum length of 100 m segment
• type of coding RAM5

It is now widely used Ethernet radio technology standardize the standards IEEE 802.11 (ISO / IEC 8802-11), which There are several modifications (IEEE 802.11a; b; d; e; f; h; X) and IEEE 802.15. At the physical level OSI model for radio Ethernet standard IEEE 802.11 defined two broadband method of information transfer.
The method of direct sequence (Direct Sequence Spread Spectrum, DSSS), which used the modulation Phase Shift Keying (PSK), and method frequency jumps (Frequency Hopping Spread Spectrum, FHSS) in which modulation used Frequency Shift Keying (FSK), the methods are incompatible with one another.
At the second level OSI model uses two sub, sub logical link control (Logical Link Control, LLC), that identically described in the standard IEEE 802.3 and sub-management access to the media (Media Access Control, MAC), using Protocol Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA), which, unlike the protocol Carrier Sence Multiple Access with Collision Detection (CSMA / CD), which is implemented in the standard IEEE 802.3, took into account the availability Half priemoperedachy (in this case Station has been unable to identify the conflict at the time of transfer Information), as described in the standard IEEE 802.11.

The protocol CSMA / CA station that accepts the package, sends in response signal correctly confirmation of the package.
The station that wishes to transfer channel package testing for the presence, in the case, when the channel is free station expects prodozh randomly certain period of time and then begin sending the package information if the channel is still available.
If the package is adopted, rightly, that his station has taken, sends a special package, which signals the station that transmitted information about Achievement transfer. And station completes the process of transferring information.
In the absence of confirming the transfer station package concludes the existence of conflicts and package information will be transmitted through again some random certain period of time.
For lack of definition in the channel used algorithm несівної Carta evaluation channel (Channel Clearance Algorithm, CCA). The essence, which is to measure the energy signal to the antenna and determining the power of the signal. If the power of the signal below the threshold level, defined as a free channel, if the above, Channel is considered employed.
Besides the possible problem of "closed point" when the station can "Hear" an access point, but did not hear "each other in consequence of obstacles or the large distances between stations.

Standards radio Ethernet.

IEEE 802.11a от 16-09-1999 ISO/IEC 8802-11 ( European analogue Is the standard HIPERLAN-2)
The speed of data transmission 54 Мбит/с
Working range of frequencies 5 ГГц
Data transfer rate 54 Mbps
Working range of 5 GHz frequencies
IEEE 802.11b (Wi-Fi (Wireless Fidelity)) от 16-09-1999
Data transfer rate 11 Mbps
The working range of 2.4 GHz frequencies
IEEE 802.11 with
Standard regulate the activities of the wireless bridges.
IEEE 802.11d
Standard governs the universal requirements to the physical level equipment IEEE 802.11 (procedure of forming channels, random sequence of frequencies and others).
The standard specifies requirements for physical channels (power radiation, the range of frequencies) devices and wireless networks.
IEEE 802.11e
IEEE 802.11e standard specifications are intended to expand operability of equipment and IEEE 802.11 standards and with the IEEE 802.11b establishment of a multiservice wireless networks.
IEEE 802.11f
Standard protocol defines the exchange of information between service points Access.
IEEE 802.11h
The standard is intended to harmonize the work of networking standard IEE 802.11, while in Europe, where in the range of 5 GHz employs some satellite System.
Data transfer rate 100 Mbps
IEEE 802.11g dated 12-06-2003
Data transfer rate up to 54 Mbps
Working range of frequencies 2,4 ГГц

2.2The model solution for technology xDSL

Figure 14. A variety of technologies subscriber access.

To build a level of access to networks of suppliers of services based on technologies and equipment xDSL (Digital Subscriber Line) Cisco Systems equipment uses Cisco NetSpeed.

xDSL technology positioned for applications data, voice and video, as well as for combining institutional telephone exchanges via telephone copper wire xDSL technology positioned for applications data, voice and videos, as well as for integrating agency for telephone exchanges copper telephone wire.

In the next few years xDSL technology could potentially be used to start the ATM delivery to accommodation and on the existing infrastructure of copper cable. The development of standards for this depends on the committees ANSI, ETSI, ADSL Forum, ATM Forum, Digital Audio-Visual Council (DAVIC). As indicated in the documents consortium ADSL Forum, ADSL technology was originally designed for the permanent transfer of traffic, rather than data packets. Nevertheless, the organization has included among its objectives to ensure full compatibility with ADSL technology protocols packet data, because it is ideal for access to networks with packet switching

The history of technology development xDSL

The first xDSL technology has been specified in the 1987 Bell Communications Research (Bellcore) - a consortium of regional operators companies Bell (RBOC). At the time, xDSL was developed to provide services video on demand and interactive television applications using twisted pair. However, in connection with the collapse of the alliance companies Bell and cable companies, technology proved to be surrendered.

Interest in xDSL resumed after it became clear that the use of fiber-optic lines as the route from the end-user devices until the first active service provider too expensive and time-consuming. Another impetus was the opportunity to compete in markets related services telephone companies, cable companies, radio / television stations, service providers access to the Internet and constant connectivity, as well as manufacturers of telecommunications equipment. Telephone companies see the opportunity to meet xDSL sharply increased interest in the Internet and demands of consumers to high-speed access to data. In December 1996 the consortium decided to develop jointly with other common methods of standardization bodies through the transfer of popular packet-oriented protocols on lines ADSL. Begin agreed with ATM, namely, the adaptation of ADSL-flow devices 53 - byte ATM-cells coming from the statistical multiplexer.

Different types of xDSL and how they work

Initial letter "x" в xDSL refers to abbreviations different types of digital subscriber line technology, including ADSL, R-ADSL, HDSL, SDSL and VDSL. To fully understand the significance of these technologies and determining the area of application of each of them need to know what they are different.

The key point is the relationship between distance to which the signal is transmitted and the speed of transmission, as well as differences in symmetry traffic upstream (to the service provider) and downstream (user). Table 1 shows a comparison of different types of xDSL technology with competing technologies, including 56 Kbps analog dial-up, cable modems and digital network integration services (ISDN). Asymmetric Digital Subscriber Line (ADSL) ADSL technology - it's a new platform for delivering broadband services to accommodation and small offices. ADSL can support a wide set of applications that require high bandwidth, such as high-speed access to Internet, teleconferencing, virtual private networks and multimedia flows. Existing technologies delivery data on switched lines such services so far, or not Support is maintained, or has insufficient Effectively. Currently, many service providers announced their plans to move the outcome of ADSL. A key factor for successful development and introduction of ADSL is its two-sided ability to interact. Thanks to this quality it is possible to use different equipment producers and be sure they are compatible. Significant progress made in installing the ability to interact on a physical Level ADSL. Number of models ADSL increases with the development and adapting to the peculiarities of test versions of the market and technical conditions. Such a solution satisfies the requirements of the following key services: .

4.TECHNICAL PRAKTIROVANIE

4.1.1 The switch access:

After considering different types of switches, appreciating some of their parameters, I chose the company switchboard 3com - SuperStack3 4250T 3C17302 E-net Switch 48port. He is portrayed in the picture4.1.

Figure 4.1 - Switch SuperStack3 4250T.

This switch works for SNMP interface is web-based interface, command line interface, supports virtual local Networks VLAN - 802.1Q. has 48 universal port Ethernet 10/100 Mbps and two ports 10/100/1000 Mbps. That is an opportunity to connect to 49 computer subscribers, the last port connects to switch distribution, which Is higher hierarchy. This is fomit switchboard, it can be combined with the type of switches SuperStack 3 Switch 4228G, SuperStack 3 Switch 4250T and SuperStack 3 Switch 4226T. He has built power supply, but also has the ability to connect backup power supply 3Com SuperStack Advanced Redundant Power System.

5 ASSESSMENT OF KACHESTVENNYH SPROEKTIROVANNOY NETWORK

5.1 Construction of the network model

Modeling object of the network used in the form of mathematical package modeling - Net Creaker, which contains the basic elements of leading firms manufacturers of telecommunications equipment, allows himself build equipment that is missing in libraries programme.

of this package is estimated Network. It shows the average, the current strain on network devices, and In the whole network. You can also see the number of packages taken and lost to Each of the devices. Rate competing in the network.

Each of these additions, together with the devices are near average rates burden on them.

5.2 Setting model

Establishing a network model species occurs tarfikov and adjusting lines connecting devices. Communication between computers knots was felt kind of Traffic - Small Office. For communication between computers and server transfer Data used type of traffic - FTP client. For this to the server was installed software.

communication between subscribers videoconferencing was set type of traffic - Data call, and for telephone subscribers - Voice Call.

As a result of the simulation revealed that the network is Employments. Some elements are present in the functional scheme absent in this package modeling, so they had to build vslanoruch thanks to special features - Device Factory.

Were raised kinds of traffic between the devices and calculated the average load indicators on the device. They do not exceed Indicators normal functioning. At switches - is to about 10 Mbps, the router - up to 8 Mbps. It should, but bear in mind that this model as a whole was created to assess efficiency network as a whole and does not take into account the total number of all functional elements of the scheme .

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