Introduction
Conditions for the formation of the telecommunications market posed by modern specialists specific tasks aimed at accelerating the implementation of important socio-economic problem - informatization of the country, joining the global information infrastructure. The scope of telecommunications is constantly updated, needs a variety of knowledge.
Known principles of analog networks are poorly suited for creating digital gap through the indicators of modern and advanced facilities and communication systems. In addition, the architecture building analog and digital networks are fundamentally different because of the orientation of the developers on the development of network services based architectures and functional capabilities ІN-NGN.
If we consider the introduction of IP-telephony, it should first be noted that there are two different approaches to the introduction of this technology. One of them is the complete rejection of traditional telephony - in this case as a channel for the connection of subscribers using a local network. The second approach, sometimes referred to as evolutionary, provides near to the conservation of traditional telephone infrastructure and the installation of new equipment, which allows you to extend the functionality of telecommunications systems.
Often designers have to deal with the latest version. The main task in this case is building a network of IP-telephony with indicators of quality and performance indicators that meet the same network that modernized.
One of the main tasks in constructing the network of IP-telephony can also be attributed the choice of necessary network equipment. In this case, the equipment that is used depends essentially indicators of network quality.
Relevance
Modern telecommunications network should not only ensure the establishment of normal connections between subscribers, but also give them access to additional services. Using IP-telephony can be a perfect solution of this problem. Implementation of such a communication system will provide users with the possibility of rapid exchange of information while reducing the cost of telecommunications.
Purpose
The aim of this work is the development of the project IP-telephony network of El Jadida Asti, which uses analytical methods for designing the network and allows to place demands on network performance, network equipment and to simulate the network IP-telephony.
Analysis object
As a design object is selected region El Jadida Asti. The area of approximately 1500 km2, the maximum length from west to east - 60 km from north to south - 30 km. El Jadida - center of the district population of 144,5 thousand. There are two large cities such as Safi and Sidi Bennour, which totaled 285 thousand and 84 thousand inhabitants, respectively.
Service providers will not be available in all communities of the district, only the big cities and smaller towns that are located near cities or are more krapnymi anchor points in comparison with their surrounding villages and small towns. We will be repelled because the nodes kernel District El Jadida Asti will be in the cities of Sidi Smail and Labkhati El Jadida. Basic equipment will be located in those cities, because of these cities in the country's transport network will go through with the highest total throughput and higher bandwidth, the more the channel, and it should be as short as possible.
Construction of the network topology
For the organization of the trunk line will use the line connecting the major nodes of the network: Sidi Smail and Labkhati El Jadida. The basic channels will be the channels linking Sidi Smail and Labkhati El Jadida. Redundant channels will also combine Sidi Smail and Labkhati El Jadida, and received physical parallel to the main road, and represent a logical structure - a ring.
To join the remote settlements with the central areas of the nodes will use a radial-node system combining redundant channels.
In order to reserve idle channels are not going to use them for backhaul, as well as basic. Thus the load generated by individual nodes can be distributed, as the main channel and on reserve.
Functional diagram of the network
Multiplexer DSLAM is a device boundary between the "last mile" network and data.
Subscribes DSLAM to the data network through the switch and router access technology Fast Ethernet (100 Vase-TX).
Then access router Fast Ethernet technology is included in the distribution rate, which in turn through a Gigabit Ethernet (1 Gbps) in the core router, which has access to the Internet. At the level of the transport network technology work Gigabit Ethernet (10 Gbit / s).
At the level of access to the switch is also included technology Vase 100-TX SIP-server, which manages the services of IP-telephony.
On the other hand DSLAM included in the subscriber's cross. Given the fact that the DSLAM has a built-in splitters, to him, except for subscribers, can also be connected interconnectors from PBX enterprise (E1-2048kbit / s). DSLAM separates streams from subscribers to telephone calls that go through the PBX to the PSTN network and data network (data, Internet, IP-telephony).
On the side of the subscriber located subscriber splitter, which divides the frequency signal to the telephone network and the signal that is intended for ADSL-modem directly connected to the workstation end-user.
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