The cabinet is equipped with the following devices:
a) RAP-BG is a distribution cabinet with the possibility of inputting power from two sources (SOURCEA, SOURCEB). It carries out switching of the secondary voltage of 48 V;
b) MiniPack CHP converts primary voltage 220 V into secondary 48 V. CHP power is determined by a set of MiniPack blocks. Two such blocks are installed on the site, the design of the CHP provides for the installation of four;
c) the SmartPack module, which is also part of the CHP, controls and monitors the state of the CHP, as well as the parameters of the input voltage of 220 V. It is connected to the SPD ECMA network via the Ethernet interface;
d) Artemis spectral optical multiplexing equipment. Implements DWDM and CWDM technology. It does not have any electrical components and therefore does not need power. With the help of it, several optical signals with separation by wavelength can be transmitted in one fiber of the FOCL;
e) The SDHBG-20 multiplexer performs multiplexing, demultiplexing operations, and also converts an electrical signal into a light one and vice versa. The BG-20 multiplexer is capable of working with 21 E1 streams, in addition, it has 6 Ethernet ports, which are also used for data transmission. BG-20 and BG-30 provide two power supplies of 48 V each, in addition, BG-30 provides for the connection of any alarm circuits to it, for example, the OPS monitoring station (centralized monitoring panel for fire and security alarms). BG-20 is able not only to work with alarm circuits, transmitting any events to ECMA, but also to control any devices using Alarms OUT. One BG-20 multiplexer provides 4 Alarms INs and 4 Alarms OUTs.
Batteries are also located in the cabinet to ensure uninterrupted power supply.
Figure 3 - CWDM cabinet configuration
3 Characteristics of communication devices of other workshops
Due to optimization, the central and combined RVB were combined into one RVB 335, thus, the equipment of another workshop is distinguished by the presence of a central workshop, ATS Definity and SMK-30 as a multiplexer.
3.1 PBX Definity
ATS is an automatic telephone exchange. The telephone exchange is a complex of technical means, the task of which is to ensure the switching of communication channels of the telephone network, to automatically transmit a call signal from one telephone set to another. This is a type of communication node, the function of which is considered to be the connection and disconnection of telephone channels for a while telephone conversations. The emergence and development of automatic telephone exchanges is directly related to telephony - a field of science and technology that studies the basic principles of telephone communications and develops special equipment.
Definity Key Features
b) high performance;
c) increased reliability achieved by duplicating the main critical components of the system;
d) increased speed and accuracy of switching for data transmission and networking;
e) support for computer-telephone integration (CTI);
f) low monthly maintenance cost;
g) a basic call control system that allows you to control up to 200 agents and 99 groups, providing flexible and cost-effective control;
h) notification of unauthorized access will stop violators in the password and remote access system;
i) CallCoverage function allows you to effectively and flexibly control each phone.
3.2.2 Main functions of the Definity system
a) abbreviated dialing - provides lists of stored numbers that can be accessed when establishing connections for local, long distance and international calls to activate features or to perform end-to-end signaling;
b) division incoming call- allows the telephone operator to notify the call of the called subscriber or confidentially consult with the called subscriber so that the other subscriber on the call does not hear, and also allows the user, after answering the call forwarded to him, to call another subscriber for a private consultation;
c) automatic call - simplifies the work of the telephone operator by simplifying the switching operation to one press of a button;
d) waiting for the release of the subscriber line - ensures that calls to a busy single-line voice terminal are put on hold and a special call waiting tone is transmitted to the called subscriber. If the call is routed by a telephone operator, then he is freed to process other calls;
e) Priority Calls - This feature allows attendant calls to be answered in order of call category. This prioritization allows calls to be handled in an organized manner during congestion periods;
e) call hold - allows terminal users to temporarily disconnect from a call, use the voice terminal for other purposes of the call, and then return to the original call or join the original call from another voice terminal;
g) direct dialing - connects calls coming over the network common use, directly to the dialed extension number without the intervention of a telephone operator. · Different types of ringing signals - helps users of voice terminals and telephony operators to recognize different types of incoming calls (internal, external or intermediate);
h) emergency call - ensures the direction of emergency calls to the telephone operator. Such calls may be automatically routed by the system or may be dialed by users of the system. The priority handling of these calls can be handled by the telephone operator;
i) Subscriber Dropout - Disconnects SLT extensions from service if users do not hang up after receiving dial tone for 30 seconds (default setting) followed by an intercept tone for 30 seconds (default setting). These intervals can be assigned.
3.2 SMK-30 as a multiplexer
Network multiplexer-hub SMK-30 is designed to work as a part of digital network data transmission (DSPD). The multiplexer works with E1/PCM-30 channels (PCC), as well as with 64 kbit/s (BCC), n x 64 kbit/s channels with different subscriber terminations.
The multiplexer allows you to organize communication between remote objects via digital channels ("point-to-point" and group) 64 kbps, n x 64 kbps with different terminations; via analog channels PM ("point-to-point" and group) with 2-wire and 4-wire terminations; organize channels for connecting lines (SL) between automatic telephone exchanges; channels for connecting remote analog and digital phones to ATS; organize a network of distributed mini-automatic telephone exchanges.
The multiplexer supports the routing function in accordance with IEEE 802.3 Ethernet, IEEE 802.3u Fast Ethernet standards at 10 and 100 Mbps in duplex and half duplex modes. To connect a subscriber device, standard connecting cables are used: 10BASE-T - UTP cable of category 3, 4 or 5 for a speed of 10 Mbps; 100BASE-T is Category 5 UTP cable for 100 Mbps.
The multiplexer can be used in networks built on the basis of SDH and PDH technologies. The multiplexer is designed for operation in networks for various purposes, including OTN and ObTS networks of Russian railways.
4 Custom Job Cisco ME-3400E-24TS-M Switch and Cisco ME-3800E-24FS-M Router
4.1 Cisco ME-3400E-24TS-M Switch
The Metro Ethernet topology is organized into three layers: the core, the aggregation layer, and the access layer. The core of Metro Ethernet is built around powerful switches and provides traffic at the highest available speeds. Switches are also used at the aggregation level to connect the access level to the kernel, collect and process statistics, and provide services. In some cases, with a small network scale, the core can be combined with the aggregation layer. Most often, data transfer between the core and aggregation layers is performed using Gigabit Ethernet and 10-Gigabit Ethernet technologies.
At the level of aggregation and the core, it is mandatory to redundant critical moments of the network, including topological redundancy and redundancy of switch components. The use of link-layer technology allows you to get a significant reduction in recovery time after a failure. The vast majority of Metro Ethernet networks have a topology recovery time that does not exceed 50 ms.
The network access layer is organized according to the "ring" or "star" scheme. At this level, subscribers are connected to the network: offices, residential buildings, industrial premises. This level implements the whole range of security measures, isolation and identification of subscribers, ensuring the protection of the operator's infrastructure. 
Figure 4 - Metro Ethernet ring structure
Cisco ME 3400 switches are located at the lower level, in their ring there is one Cisco ME 3800 router, which has access to a higher level, that is, the core.
The Cisco ME 3400 Series Ethernet Access Switches are 24-port devices that are designed to fit in back office environments that serve multi-family homes, office buildings, and small areas.
Equipped with 10/100 Mbps ports, the switches serve the exponentially growing end-user traffic that today typically uses dedicated xDSL circuits. The switches are equipped with two fiber-optic ports connected to the carrier's infrastructure using FTTP (fiber to the premises) or FTTN (fiber to the node) technology. Each port on the ME 3400 switch is assigned to only one subscriber; wherein Information Security provided at the port level. This approach eliminates the possibility of intercepting packets that are sent to users connected to different ports.
The Cisco ME 3400 Ethernet Switches can withstand heavy loads during multiple connections and massive use of system resources. The transmission of information, video and voice is performed at acceptable speeds for the user. Unauthorized access and traffic are excluded by connecting special protection systems that can completely isolate the user from possible hacking attempts. Working with such switches is easy, fast and reliable, since the transmission is carried out in a continuous stream.
UNI/ENI/NNI interface types:
UNI (user network interface) ports are used to connect end equipment and block traffic that is unnecessary for the user like BPDU, VTP, CDP and some others, and also allow you to isolate clients located in the same VLAN from interacting with each other (or allow you to select a group of ports that can communicate with each other);
NNI (network node interface) ports are used to connect two switches. Do not impose restrictions on the protocols walking on them;
the ENI (enhanced network interface) port is almost like UNI, but allows you to enable certain protocols that are completely blocked in UNI.
Figure 5 - Cisco ME 3400.
4.2 Cisco ME-3800E-24FS-M Router
Routers (routers) Cisco are designed to implement a policy for access control in a packet data network, combining its elements, redirecting traffic to less busy areas. main function routers is the most efficient determination of the optimal path for transmitting packets between destinations. Route selection is based on certain criteria and is based on information about the network topology and routing algorithms.
The Cisco 3800 is a high-performance series of Integrated Services Routers (ISRs). The Cisco 3800 Series routers combine security, voice, and other intelligent services in a single compact platform, eliminating the need for multiple separate devices. Many service modules, such as modules voice mail, intrusion detection modules, traffic caching, etc., have their own hardware resources that eliminate the impact of services on the performance of the router and at the same time manage using a single management interface.
The Cisco 3800 Series Integrated Services Routers include the Cisco 3825 and Cisco 3845 routers. Both routers support WAN interface cards (WICs), data-only voice/WAN interface cards (VWICs), single high-speed WAN interface cards (HWICs), and optional integration module (A.I.M.). The differences between these routers are as follows:
The Cisco 3825 routers support 2 network module slots. The bottom network module slot can contain either 1 single network module or 1 extended single network module. The top network module slot can contain either 1 single network module, 1 extended single network module, 1 dual network module, or 1 extended dual network module. The Cisco 3825 routers also support 1 additional SFP slot, 2 built-in Gigabit Ethernet LAN ports, 2 built-in USB ports for future use, 4 single or 2 dual HWICs, 2 AIMs, 4 PVDMs, 24 power ports for IP phones, and hardware encryption, and VPN acceleration. Power to IP phones is supported if the appropriate AC power supply for the chassis is installed.
The Cisco 3845 routers provide 4 network module slots labeled 1, 2, 3, and 4. Each slot supports one of the following modules: Single Network Module, Enhanced Single Network Module, or Enhanced Extended Single Network Module. Slots 1 and 2 are combined to support dual network modules or extended dual network modules. Similarly, slots 3 and 4 are combined to support dual network modules or extended dual network modules. The Cisco 3845 routers also support 1 additional SFP slot, 2 built-in Gigabit Ethernet LAN ports, 2 built-in USB ports for future use, 4 single or 2 dual HWICs, 2 AIMs, 4 PVDMs, 48 power ports for IP phones, and hardware encryption, and VPN acceleration.
The functionality of the Cisco 3800 series routers is confirmed by the fact that the equipment supports IP telephony. Integrated Support voice functions, rather high density of voice ports – distinctive features new line of routers. The devices provide reliable support for a large number of previously released voice modules. It is important to note that digital processors can be installed directly on the router motherboard. Today, the 3800 series routers support about twenty-four digital E1/T1 ports and up to eighty-eight analog FXS ports.
The Cisco 3800 Series Routers are designed around switching. Such routers allow you to change performance. This means that the unique technology used allows you to combine routing flexibility and high switching performance at the same time. The transmission of data and voice streams, the processing of information occur simultaneously at different levels. Thanks to this processing, the throughput of switched speech and data flows increases. However, the benefits of Cisco IOS routing are retained. Routed IP flow and switched flows are supported simultaneously.
Modern Cisco 3800 routers are managed centrally. This management reduces operating costs. At the same time, all fault reports are recorded in one place, which allows you to quickly respond to problems and quickly resolve them.
Flexible compact multi-service platform for wide area networks and metro access networks - BroadGate BG-20Today's cellular and access networks require more and more bandwidth to carry traffic various systems: base stations 2G, 2.5G and 3G, SDH optical rings, chains, point-to-point connections and radio links. At the same time, operators and service providers are striving to provide enterprise customers with broadband services using existing infrastructure and are trying to reduce equipment power consumption, space and overall cost. In addition, by creating their own networks, government, military, energy and telecommunications organizations expect that one network can provide highly efficient access and traffic for all types of services and will significantly reduce initial and operational costs. ECI Telecom's BG-20 Compact Multi-Service Platform (MSPP) addresses these challenges and more.
Multiservice platforms have begun to play a critical role in the transition from traditional networks to next generation networks. The BG-20 platform allows backbone providers to effectively use the installed infrastructure of SDH networks and increase the number of services provided. With scalability, a wide range of networking and security capabilities, this platform can improve the cost-effectiveness of operating metro access networks and private networks that combine transmission and service access functions. In addition, the BG-20 platform allows you to respond in a timely manner to the need for network expansion.
Key Features and Benefits
ECI Telecom's BG-20 platform is an affordable and cost-effective solution that supports Ethernet, SDH, PDH (Plesiochronous Digital Hierarchy) and PCM technologies, providing companies with new business opportunities. The BG-20 provides ample opportunities and provides whole line benefits, including those listed below.
- Highest expandability thanks to sharing BG-20B platforms and BG-20E devices enable build-as-you-grow™ solutions.
- Possibility of gradual expansion depending on current needs. Ease of adding new STM-1 interfaces and the ability to upgrade STM-1 interfaces to STM-4 with minimal traffic impact. Flexible and easily adaptable architecture can significantly reduce capital and operating costs.
- A backbone-class solution for transporting Ethernet traffic over WANs and metro access networks, providing the data service control, security and reliability inherent in SDH networks.
- Grooming at the level of one optical channel, ensuring high utilization of the existing fiber optic channel and high transmission efficiency various types services.
- PCM interfaces and 1/0 digital cross-switching functions facilitate the creation and operation of private networks.
- Support for multi-ADM mode and cross-switching functions make this platform the best choice for deployment in networks with flexible topologies (for example, ring and mesh topologies, as well as star topologies).
- Compactness and reliability, allowing you to install this platform both indoors and outdoors. The wide operating temperature range also allows the platform to be used in a wide range of environmental conditions.
BroadGate BG-20 is a flexible multi-service platform that can be used to solve various problems. Wide networking capabilities and security features, excellent expandability, as well as small size and low cost make this platform perfect choice for creating cellular networks and metro access networks. BG-20 improves the efficiency of service access, aggregation and service transmission, making these services an integral part of today's networks.
Areas of use
Application in data networks
In recent years, Ethernet services have been driving the telecommunications industry and driving new approaches to providing and accessing data services. This caused a rapid increase in the requirements for bandwidth and cost reduction. The BG-20's Layer 1 and Layer 2 Ethernet service capabilities provide backbone providers with an easy way to transition from traditional TDM-based services to new, more profitable services. Using the BG-20, backbone providers can provide Ethernet Private Lines (EPL) circuits to customers instead of traditional leased lines based on TDM technology, Ethernet circuits Virtual Private Lines (EVPL) to share bandwidth, and Ethernet Private LAN (EPLAN)/Ethernet Virtual Private LAN (EVPLAN) to connect corporate local networks using the global network. All services can be provided with a Quality of Service (QoS) mechanism and a Service Level Agreement (SLA). Compliance is managed and monitored by ECI Telecom's LightSoft multidimensional network management system.
Aggregation of IP DSLAMs
The BG-20 platform uses packet policies and queues to ensure the required quality of service and manages bandwidth usage at the packet level. Since many customers require a fully guaranteed quality of service, BG-20 allows you to provide various customers different levels QoS, as well as provide different levels of QoS to a single client.
Application in metro access networks
At present, the requirements of individual and business users for the bandwidth of metro access networks are increasing, due to the need to support services working with conventional, voice and video data. Although the BG-20 platform is very compact, it provides access traffic aggregation for STM-1/4 interfaces in point-to-point and multi-ring networks. The BG-20 receives and transmits PDH, SDH and Fast Ethernet traffic at local points of presence.
Application in cellular networks
Due to the continued growth of the market cellular communication operators have to deal with ever-increasing traffic volumes, increasing bandwidth requirements affecting network topology, and the need to migrate to new technologies (from GSM to GPRS and then to 3G). All these changes require the use of a flexible and scalable optical infrastructure in remote access networks.
The BG-20 platform is an excellent choice for building such networks due to the following features:
- Compact and robust, allowing this platform to be installed both indoors and outdoors in harsh environments.
- Consolidation of data traffic and TDM traffic for a common infrastructure.
- Support for ring, mesh, and point-to-point topologies. Ability to upgrade STM-1 interfaces to STM-4 with minimal traffic impact.
- High flexibility and low price, increasing the economic efficiency of the u1089 network.
- Efficient processing of modern data services (migration to WLAN and IP) provided by mobile operators.
- DXC 1/0 crossover and low speed PCM interfaces allow remote control and monitor the operation of various types of cellular base stations and base station controllers, eliminating the need for conversion units and reducing capital and operating costs.
As a rule, energy, military, telecommunications and government agencies tend to create their own communication networks. This is done for security purposes or because the services offered by existing carriers do not meet the requirements of these institutions. In order to reduce operating and infrastructure costs, private network users are trying to create a single network that satisfies all data transmission and service access requirements. Networks support many types of services and interfaces. While most hosts typically only need interfaces to a small number of services, the requirements for network reliability are very high. The BG-20 platform integrates data and TDM traffic into a single infrastructure and handles advanced data service traffic with high efficiency. This is made possible, in part, by the fact that the BG-20 platform combines an integrated DXC 1/0 cross-switch and PCM interfaces for low-speed data transfer, local PBX numbers, and hotline telephones.
The BG-20 platform is designed to meet the growing needs of today's networks, such as lowering the cost of operating city-level systems or cellular systems. The ability of the BG-20 platform to meet the existing needs of the network and ensure its evolution allows the BG-20 to be used as a key element in creating highly competitive solutions and allows operators to cope with unpredictable load growth without restructuring the network.
Fiber-optic communication lines are being laid along the railway using STM-16 transmission systems (2488.32 Mbps). According to the project, network nodes with synchronous input / output multiplexers SMS-150C and BG-30 with cross-connector functions are planned at the station, providing a branch of high-speed streams of 155 Mbit / s, interaction of STM-1 and STM-16 of the lower level and allocate the required number of E1 streams. According to the project, 5 E1 streams and 17 E1 BG-30 streams will be allocated to SMS-150C.
All equipment is covered by the TMN control system. Local network subscriber terminals are included in the switching equipment of the secondary network, which is connected to the primary network through E1 joints.
The main purpose of STM-1 is to provide E1 streams to secondary networks at the road and departmental levels. At the backbone level, a more powerful STM-16 transmission system is used to interconnect road nodes and for redundant STM-1. The allocation of the required number of E1 streams from STM-1 is organized by synchronous input / output multiplexers. The primary communication network, which is the basis of the network, determines its main characteristics: reliability, bandwidth, manageability.
On the basis of the primary digital communication network, a secondary communication network is formed to organize general technological communication, operational technological communication and data transmission.
In accordance with what was written above, in order to organize a primary digital communication network of a road level, it is planned to install the main I/O multiplexer of the BG-30 brand from the BroadGate company in the graduation thesis, and SMS-150C will be used for backup.
I/O multiplexers BG-30 and SMS-150С
The SMS-150C is a third generation Synchronous Digital Hierarchy (SDH) multiplexer designed as part of NEC's SDH series of products. It uses the features of the STM-1 multiplexer to provide greater versatility in network applications. The specific functions of the SMS-150C are determined by the configuration.
SMS-150C type SDH transmission system multiplexer operating on two fibers with a digital stream of 155 Mbit/s. It provides allocation of up to 21 E1 streams.
At the stations, 7 E1 streams of each direction will be allocated.
The E1 streams allocated by the SMS-150C multiplexer are used for the technological communication network (OTS, ObTS and PD):
Features of SDH multiplexer SMS-150C:
Compact size for mounting in a cabinet;
Allocation of up to 21 channels 2Mbps (G.703);
2-fiber SNC-P ring redundancy with path redundancy at VC-12 and VC-3 layers;
Supports terminal multiplexer mode with 1+1 MSP traffic line redundancy;
Allows performance monitoring (G.826);
Possesses function (ALS) of automatic extinguishing of the laser (G.958);
Equipped with external sync signal input;
Allows you to download software remotely;
Equipped with interfaces alarm the state of the premises (NKA) and the control of the state of the premises (NKS);
The SMS-150C multiplexer is located in the Ob-128Ts equipment cabinet, which is located at station S.
BG-30 is a multiplexer of STM-1 - STM-16 levels, both terminal and I/O topologies. The BG-30 provides PCM, TDM, 10/100 BaseT and GbE data interfaces. Ethernet traffic is located in n*VC-12/VC-3 containers using standard VCAT and LCAS. BG-30 Figure 3.3 is a more powerful and scalable platform that allows you to effectively expand existing networks both medium and large enterprises according to the needs. The uniqueness of the BG-30 multiplexer also lies in the fact that it fully allows you to utilize the capacity of the STM-16 channel using EoSDH technology using a 1U form factor.
Figure 3.3 BG-30 Multiplexer
Multiplexer BG-30 consists of:
2U BG-30E - expansion platform
64xVC-4 cross-connect matrix
Client interfaces from STM-16/GbE to 64Kbit/s: STM-1/4/16, E1, E3/DS3, FE, GbE, FXS, FXO, 2W/4W E&M, V.35, V.24
BG-30B Ethernet: L1/L2 with QoS and GFP/LCAS
1U BG-30B - base platform
BG-30 also operates under multidimensional control network system LightSoft controls. Network transceivers are used to transmit and receive a signal between two physically different environments of a communication system. The choice of the transceiver is carried out in accordance with Table 3.2. Transceivers of different types can be installed in one system module.
Table 3.2 - Laser optical transceivers
|
Wavelength, nm |
Output power, dB |
Minimum input power at an error rate of 10 -10 , dB |
Range (including margin for aging and connections), km |
||
And networks"
on production practice
Organization of operational and technological communication based on BG-20 and BG-30
Place of internship:
Student gr. 23a
2016
Production manager
practices
Associate Professor of the Department of TRSiS
Grade: _____________________
_____________________________
201__
2015/2016 academic year
Introduction………………………………………………………………………………..3
1 Main part………………………………………………………………………….4
1.1 Building a primary digital network…………………………………………...4
1.2 Equipment BG-20 and BG-30…………………………………………………….....7
2 Organization of TSO on the Khabary-Srednesibirskaya section…………………...……12
Conclusion………………………………………………………………………………..17 References………………………………… ………………………..eighteen
Introduction
This work is a report on the passage of industrial practice at the enterprise, the purpose of which is to consolidate the knowledge gained in the process of studying the theoretical foundations.
The main direction in the development of operational and technological communication networks (OTC) is the replacement of analog switching equipment with digital and its integration with digital transmission systems.
To organize operational and technological communication channels using digital transmission and switching systems, specialized switching stations are used.
On the example of equipment "BG-20" and "BG-30" the issue of building selective telephone communication between the dispatcher and subscribers located along the railway line is considered.
Setting up a communication channel involves setting the parameters of the ports for enabling subscribers, which differ in location and level of administrative responsibility.
The transition to the BG platform allows you to meet the requirements of railway transport in the field of supply modern means communication, as well as increase the data transfer rate compared to SMS-150. This equipment has ultra-high scalability by connecting expansion modules to standard BG modules, provides Ethernet over WAN/MAN networks. The high stability of traffic due to the redundancy of the main hardware provides an increase in the reliability and uninterrupted operation of all types of communication used in freight and passenger transportation.
1 Main body
1.1 Building a primary digital network
The development of local networks is carried out on the basis of a synchronous digital hierarchy. The main difference between SDH and PDH networks is the use of a master oscillator, in other words, a synchronization source. Extracting it from the schematic will turn the SDH network into a PDH network. The main disadvantage of PDH is the inability to extract a lower layer stream from a higher layer stream without completely demultiplexing the stream, which is often uneconomical. The main feature of this hierarchy is the transparency of the multiplexing process. This makes it possible to directly allocate the main digital channel (BCC) 64 kbps directly from the streams of any SDH hierarchy. This makes it possible to reduce the number of expensive equipment and increase the flexibility of the system.
General features of building a synchronous hierarchy:
a) support as access channel signals only tribs (trib, tributary - component signal or load, load flow) PDH and SDH;
b) tribes must be packed in standard header-labeled containers, the dimensions of which are determined by the level of the tribe in the PDH hierarchy;
c) the position of the virtual container can be determined using pointers to eliminate the contradiction between the fact of synchronous processing and the possible change in the position of the container within the payload field;
d) several containers of the same level can be chained together and considered as one continuous container used to accommodate a non-standard payload;
e) provision is made for the formation of a separate header field with a size of 9∙9=81 bytes.
In this section Kamen - Khabary - Central Siberian SDH hierarchy includes the STM-4 layer (622, 080 Mbps), a synchronous transport module. The collection of E1 input streams (30 channels at 64 kbps) through access channels into an aggregate block suitable for transportation in the SDH network is called multiplexing and is performed by terminal multiplexers - TM of the access network. At this stage, containers and virtual containers are formed from E1 tribes with sequential multiplexing and adding routing headers with service information. Gradually, during the assembly steps, the length of the container increases, and in 8 steps a synchronous transport module STM-4 is formed.
The organization of the communication center at the Kamen-Khabary-Srednesibirskaya section is shown in Figure 1.
The SDH multiplexer has two groups of interfaces: user (tributary) and aggregate. The first group allows you to create custom structures (output of E1 or BCC streams), and the aggregate (optical) one - to create linear inter-node connections. These connections form several basic topologies.
To create fiber-optic communication networks, a ring topology is used here as a redundancy, the scheme of which is shown in Figure 2.
Figure 2 - "Ring"
The main functional module of SDH networks is a multiplexer. SDH multiplexers perform both the functions of the multiplexer itself and the functions of devices terminal access, allowing low-speed PDH hierarchies to be connected directly to their input ports. It should be noted that the E1 stream in the connected device (NEAX-7400 or SSPS-128) is completely demultiplexed and the use of PDH here will not cause unnecessary costs. They are universal and flexible devices that allow solving almost all of the tasks listed above, i.e., in addition to the multiplexing task, to perform the tasks of switching, concentration and regeneration. In this section, an optical transport platform based on dense wavelength division multiplexing technologies - DWDM (Dense Wavelength Division Multiplexing) is used.
This is implemented on the basis of Artemis equipment. The communication network is organized on the basis of modern BroadGate (BG) equipment manufactured by ECI Telecom, which combines Ethernet and SDH services.
1.2 BG-20 and BG-30 equipment
DWDM technology implies the spectral division of the fiber bandwidth into several optical channels. Thus, several independent channels (each at its own wavelength) are transmitted in parallel in one pair of fibers, which makes it possible to increase the throughput of the transmission system.
The BG platform offers a wide range of special features and benefits:
a) ultra-high scalability by connecting extension modules to standard BG modules, which ensures the build-as-you-grow® principle (build as you grow);
b) carrier-class ethernet over WAN/MAN networks with security, data service control and reliability of SDH technology;
c) High traffic stability due to the redundancy of the main hardware and tributary protection;
d) the ability to add interfaces to the network element without shutting it down by installing the appropriate boards: from E1 for several ports to STM-4/STM-16/STM-64 boards;
e) optimization of network traffic at the level of one optical channel
to improve the efficiency of the use of existing fiber and the transmission of different types of services;
e) PCM service interfaces and 1/0 digital cross-switching functions, facilitating the construction and maintenance of various private networks;
g) multi-ADM and cross-connect functions, ideal for use in flexible network topologies such as ring, network and star;
h) compact and fault-tolerant, this platform is perfect for indoor and outdoor distribution cabinets. Thanks to its extended operating temperature range, it is also suitable for use in harsh environments.
By providing data services, the BG platform provides the following benefits:
a) capital cost savings (less equipment used) and optimization of bandwidth usage;
b) reduced operating costs due to the cost-effective integration of Ethernet and SDH into one platform with unified system management;
c) various Ethernet services implemented using one
physical port;
d) statistical multiplexing and interfacing of networks and equipment of Internet providers.
DWDM equipment st. Stone - on - Ob is shown in Figure 3.
https://pandia.ru/text/80/320/images/image005_51.jpg" width="440 height=219" height="219">
Figure 4 - Application of BG
BG-20 includes two subsystems: BG-20B and BG-20E. The BG-20B platform is a basic module that can be used alone, the BG-20E system is an expansion module that can be added to the BG-20B platform to provide more services and interfaces.
BG-20C_DC uses power - 48 V direct current, has two connectors for connecting to an external power line and supports a dual power line for redundancy. Appearance front panel is shown in Figure 5.
Figure 5 – BG-20C Platform Front Panel with DC Power
The BG-20B platform has one slot used for power module configuration. The MXC-20 board combines a cross-connect matrix, a synchronization unit, 2 STM-1/4 interfaces and 21 E1 interfaces. The appearance of the front panel is shown in Figure 6.
Figure 6 - Front panel of the BG-20B platform
The BG-20E shelf is an extension or slave of the BG-20 platform and must always be connected to the BG-20B shelf. The appearance of the front panel is shown in Figure 7.
Figure 7 - Front panel of the BG-20E platform
The BG-30 supports interoperability with the XDM and BG-20 platforms in all aspects, including SDH, PDH, data links, DCC, control and other network layer functions. The appearance of the front panel is shown in Figure 8.
Figure 8 - BG-30B front panel
The shelf consists of the following parts:
a) two connectors for power supplies;
b) one slot for MCP30 main control processor;
c) two connectors for XIO30 boards;
e) three slots for traffic cards (Tslots).
The BG-30E contains three expansion card slots supporting various types of PDH, SDH, data link or PCM expansion card interface. The appearance of the front panel is shown in Figure 9.
DIV_ADBLOCK82">
Figure 10 - Redundancy using dual fiber
2 Organization of operational and technological communications on the section Kamen - Khabary - Central Siberian
The creation of a digital OTN network should be carried out simultaneously with the digitalization of the primary OTN network. The OTN network must be built on a primary digital stream of 2.048 Mbps, which is formed on separate fibers of a fiber-optic line using the hardware included in the switch, or is separated from the digital primary network.
Half of the channels of one stream of 2.048 Mbps are intended for organizing OTS group channels, the rest of the BCC 64 kbps of this stream and three other primary digital channels(PCC) can be used to pull dispatch circles to the control center, organize a downstream data transmission network (PD). The structure of the BCC channels of the first digital stream of 2.048 Mbps should provide a group channel mode for organizing all types of dispatch communications.
Peripheral equipment initially remains analog. For the reservation of the main types of OTN and the organization of long-distance communication (PGS), inter-office communication (ISC), a cable with copper conductors is used.
A certain disadvantage of the described OTN system is the organization of group channels assigned to each type of dispatch communication, and the low use of the bandwidth of the fiber-optic communication line creates the prerequisites for building an integrated network for all types of communication.
The hierarchical construction of the OTN system provides for a three-level structure of communications, and implies the inclusion in its composition of a part of already existing and newly built information transmission systems. The existing scheme for constructing an OTN system based on BG-20 and BG-30 is shown in Figure 11.
Figure 11 - Scheme of building an OTS system based on BG-20 and BG-30
Level 1. It is proposed to use the SDH network under construction as backbone switching channels. In the support centers, SDH BG-20 and BG-30 switches are installed, interconnected by trunk fiber-optic communication lines. These switches provide access to a high-speed network over 2048 kbps flows to the following system layers, which are shown in Figure 12.
Figure 12 - Scheme of connecting the levels of the OTS system
Level 2. The main task of this level is to ensure the creation of a group channel and the connection to it of a number of subscribers of various types. This ensures that the interfaces are compatible with existing analog equipment. At this level, SSPS-128 converters connected by ISDN PRI channels and NEAX 7400 ICS M100MX stations connected by SS#7 channels are used. At the same time, SSPS-128 and NEC M100MX are connected at one station. Structural scheme shown in Figure 13.
Figure 13 - Connection diagram of the logical structure of the OTN network
Level 3. It is the level of switching equipment where NEAX 7400 digital stations are used. Its task is to ensure the operation of consoles and other OTN subscribers, as well as their interaction with level 2. For this, a separate E1 stream is used, which connects NEAX 7400 and SSPS-128. In case of a physical break, a backup line is provided through one of the racks of neighboring stations. This capability is determined by the exchange hardware. (This has been implemented on the Khabary-Sredne-Sibirskaya section.)
The individual rings are interconnected as shown in Figure 12 using a bridge converter.
The bridge converter performs the following functions:
a) supports the upper layer transit flow;
b) connects the group channel to the lower level controller through one E1 stream, while 30 group channels can be switched from the upper level to the lower one.
Options for using the SSPS-128 converter:
a) group channel controller;
b) a control device that interacts with the digital transmission system;
c) switching and channel-forming equipment with dedicated PCC, BCC, data transmission channels;
e) ensures the exit of subscribers of the switching station to the group channel;
f) includes connection equipment;
g) four wire channels PM;
h) two-wire terminations for organizing analog branches from a digital network via physical lines;
i) two-wire terminations for the organization of communication via physical lines of a stage communication;
j) two-wire endings for connecting MZHS lines;
k) radio stations;
l) registrars of negotiations.
The converter is a metal case shown in Figure 14.
Figure 14 - Converter SSPS-128
The switching station, shown in Figure 15, is supplied as a housing with a PZ-PW121 power supply installed and system board bwb. The housing provides nests (slots) for installing electronic boards. The system board contains connectors for connecting electronic boards, LTC0-3 connectors for connecting installation cables (output to the cross-connect), and connectors for connecting power supply cables. The set of these boards determines the functionality of the station. For example, Art. Dam allows you to connect PTN subscribers and city subscribers to one NEAX-7400 station by installing an additional streaming board, through which it connects to the Definity ATS junction station at st. Stone-on-Obi. Thus, 4 E1 streams are connected to the NEAX-7400 station.
Figure 15 - Switching station NEAX-7400
The group channel of digital technological communication is organized using digital systems transmission and switching.
As a transmission system, a synchronous multiplexer of the STM-4 level is used, operating over a fiber-optic communication line.
Switching stations for administrative and executive purposes implement the technology for connecting subscribers to a group channel. In the group channel, the dispatcher control principle is adopted, which consists in the presence of a dispatcher station and intermediate subscriber points subordinate to it. The dispatcher has priority in the process of negotiating with subscribers, which is the possibility of interrupting the speaker. Waypoints are called by the selective calling method.
The presence of transmission and switching functions in the group channel served as the basis for the ring technology of its construction. There are rings of the upper and lower levels.
The basic principles of the group channel:
a) a guarantee that the subscriber will receive messages from the dispatcher;
b) minimizing the passage of noise, interference and echo into the group channel;
c) compatibility with all types of analog equipment (including PU4D and US 2/4);
d) widespread use of digital devices;
e) the possibility of using conventional analog telephones;
f) the possibility of full duplex operation for digital devices and consoles (in some cases, analog devices);
g) switching of hop communication lines (SCL) directly to the group channel;
h) the possibility of using amplifiers for receiving and transmitting;
i) widespread use of voice control devices (VUG).
Conclusion
At the enterprise of the Kamensky RCS during the internship, the necessary skills and experience of practical work were mastered and acquired.
The practice began with familiarization with the internal labor regulations, with an introductory briefing, study of instructions on fire safety and labor protection. Further acquaintance with the equipment of the RCS enterprise was carried out - 4 tbsp. Stone - on - the Ob. The work was carried out under the supervision of the head.
To compile the report, we used information obtained during the internship, as well as information obtained from technical documentation, and information taken from electronic resources.
In the first section, the principles of building a primary digital network and the structure and general information about the equipment BG - 20 and BG - 30.
In the second section, an analysis was made of the organization of operational and technological communications in the Kamen - Khabary - Sredne-Sibirskaya section.
Bibliographic list
1. Passport of the communication center Art. Stone-on-Obi
2. Official site of Telecom Networks. Electronic resource http://www. telecomnetworks. en/vendors/eci/broadgate/bg20/
3. DWDM systems: features and applications. Electronic resource http://www. ccc. en/magazine/depot/03_04/read. html?0302.htm.
4. Gorelov, GV Telecommunication technologies in railway transport. Textbook for universities. D. Transport / G. V. Gorelov, V. A. Kudryashov, V. V. Shmytinsky et al. M.: UMK MPS Rossii, 1999. 576 p.
5. BroadGate® product family. General description.
The BG-20 is a unique, fully integrated SDH multiplexer designed for access networks and corporate networks, which supports services of the first and second levels.
The BG-20 is a STM-1 to STM-4 layer multiplexer for both terminal and I/O topologies. The BG-20 provides PCM, TDM, 10/100 BaseT and GbE data interfaces.
Ethernet traffic is located in n*VC-12/VC-3 containers using standard VCAT and LCAS. The BG-20 is a scalable platform that allows you to effectively expand existing networks to meet the needs of both medium and large enterprises.
The BG-20 provides the ability to take advantage of scalable SDH, WDM and data (Ethernet, IP, ATM, SAN) solutions from metro access networks and client terminations to the transport layer. High interface density. All interfaces are front-facing up to 6 x STM-1 or 3 x STM-4, replacement of STM-1 interfaces with STM-4 does not affect flow continuity.
BG-20 consists of:
- 1U BG-20B - base platform
- 2U BG-20E - expansion platform
- 16VC-4 x 16VC-4 @ VC-4/3/12 cross-connect matrix
Client interfaces from STM-4/GbE to 64Kbit/s: STM-1/4, E1, E3/DS3, FE, GbE，FXS, FXO, 2W/4W E&M, V.35, V.24.
BG-20B Ethernet: L1/L2 with QoS and GFP/LCAS.
Operating under the control of a multidimensional network management system LightSoft BG-20 provides the ability to control and manage all the physical and technological layers of the network.
The BG-20 is the ideal solution for service providers mobile operators and communication companies.