Cabling Business Magazine
Cabling Business Magazine
A rapid improvement in the quality of service offered by modern information technologies as well as a compact fitting of office building with automation systems go along with a rapid increase in information flow and transmission rates. At the same time, this requires an advanced Structured Cabling Systems (SCS), which serves as the physical platform for all these systems, with improved requirements not only for bandwidth of individual cabling components and the whole information channel, but also to SCS functioning as a whole.
At present, the application of interactive control systems seem to be the most efficient way to solve managerial problems of SCS in real time. Under such systems we understand hardware and software systems, which are included in SCS of a certain manufacturer as regular components and monitor the state of ports on patch panels in equipment rooms using computing tools without any mediation of the system administrator. This engineering branch of interactive control systems is quite new, as production samples of such equipment have been implemented in cabling projects only since the late 1990s. According to statistics from 2001 the market offers three main types of these systems. The aim of this case study is analysis of principles and design features of such systems (product companies are indicated in alphabetical order), functional capabilities and economical aspects. .
Review - (Patch System by Avaya Communications
For the first time the company Avaya Communications demonstrated the iPatch system (its prototype is known as the Smart Patching System) during the Cebit exhibition in March 2001. The iPatch system includes such hardware and software tools as panels with connection sensors, control modules of two various types and special-purpose software.
IPatch panels are available in two options for 24- and 48-ports. Depending on outlet types they ensure bandwidth performance of Category 5e or 6. The panel is equipped with a modular jack with three independent exterior elements: patch cord sensor, LED and button. The sensor looks like an active plate, which provides electrical contact registered by control module. The plate sits in the upper part of the modular jack and partly covers the opening. The plug is inserted in the jack and presses the bevel of the plate turning the plate upwards to make a contact. The red LED functions as the element for visual communication between controlling software and operator during changing the configuration of the cable system. The button is used for control in current mode, i.e. when pushed the LED illuminates the port at the other end of the patch cord. Control modules or managers have two different modifications. Rack Manager supports functioning of interactive control system that serves up to 40 panels (24-ports). Thus, the widely used 42-U mounting rack needs only one control module. Network Manager is used to cascade these modules in order to increase the number of ports. Up to 99 Rack Managers can be connected to one Network Manager. Thus, theoretically iPatch may serve approximately up to 95,000 ports.
The main distinctive feature of the iPatch control module is large-format multiline liquid-crystal display of rather large size. The display serves for input of directives of context-dependent menu, messages, operator tips and other service information. There is also an acoustic system in case of any incorrect action.
Both module types are designed in form of 19" shelves and 2U in height. The depth of this device makes it possible to install them in such narrow mounting racks as wall frames. The Control module may function in remote and direct-touch modes. And the Control Station operates remotely. Six buttons next to the display enable inputting of directives directly from the equipment room. Four buttons are located along the long side of the display and used as menu buttons, but two buttons along its right edge serve for cursor vertical update. The rear housing serves for connection of control module with panels.
Cable system control software is distributed under the trademark System Manager, and installed on the Control Station, operates in Windows 95/98, and has modern Explorer-type graphic user interface. This software provides such functions as Rack Managers and Network Managers control, update of database of connections, creation of tasks and other similar operations.
Depending on the complexity and topology of a controlled SCS as well as the presence of LAN and its structure, the iPatch system can be designed in three main variants (Figure 1).
According to designers, the standard configuration is commonly used and combines the iPatch patch panels in one system by means of the system bus and connects them to the Rack Manager. Information exchange between control modules of the Rack Manager and System Manager software runs via ТСРЯР. A distinctive feature of the alternative configuration is integration of the Network Manager control modules via interface RS-485. One of the Network Manager modules, which has a central position in this configuration, is connected to the Control Station by means of the network with setup System Manager software via TCP/IP. Both reviewed network configurations of interactive control monitor connections and notify the administrator about the troubles, which may arise in equipment room. They also send programmed tasks to iPatch panels in all racks. Finally, the simple configuration integrates only control modules of Rack Manager via interface RS-485. The system is limited to only monitor connections and send trouble-and-failure reports to administrator.
IPatch logic enables the processing of alert messages from sensors. Rack Manger scanner records the alerts. The information is written on a hard disk of the Control Station for creation of a database of connections and for further processing.
iTracs Technology by Cablesoft
Cablesoft completed development of iTracs technology at the end of 1990. A distinctive feature of this engineering solution was that it aimed at on-line cabling control tasks without orientation on a specific manufacturer of SCS components. This feature of iTracs was achieved by making hardware in the form of hookup components, which are external with respect to controlled components. Theoretically, it is possible to install them on an object directly by the user, but normally, such components are preinstalled with minimum changes improving their aesthetic appearance, serviceability and reliability.
Three basic elements form the system: panels with sensors and special-purpose patch cords, analyzers and controlling software. Panels that support iTracs technology differ from traditional devices of this type by built-in contact sensors with contact plates as the sensor elements. The plates are individual for each port and fixed on the front of the panel.
Patch cords are flexible multiwire conductors and standard modular plugs. A ninth conductor serves only for transmission of controlling signals. Unlike the cable conductors carrying telecommunications functions, it does not touch the working zone of the plug, but the pin contact is integrated into the front part of the protective boot and protrudes from it by several millimeters. At connection of the patch cord the contact sensor plates of two ports close via pin contacts of the plug and the ninth conductor of the cable. The system uses connection or disconnection of conductor to control communications.
Control modules called Analyzers are equipped with elements to fix in a 19" rack. Racks fit modules of 1U or 6U (depth is 300 mm for both options) depending on their modification. It is possible to order up to six models of these devices for different applications. Connection of the analyzer to panels is via cables with a standard length of 2.1m. It is allowable to increase the length up to 100 m, if necessary.
1U analyzer has a slot for fastening to a plate that controls 256 ports of patch panels. On the front panel of the analyzer there is a liquid-crystal display for controlling and information messages. There is a line of six buttons under display for updating of cursor and for command quitting. A large analyzer with a height of 6U has eight slots to install plates for connection of panels, i.e. the number of controlling ports increases up to 2048. iTracs technology enables stand-alone use of components as well as cascading in order to control SCS with large number of ports. (Figure 2) In the latter case several Link Analyzers link up to the Master Analyzer. This function increases the number of ports up to 18688 with a 1U device, and up to 20480 ports with a 6U device, which functions as the Master Analyzer.
Individual analyzers can be remotely controlled via 10/100 BaseT through the TCP/IP network, as well as via RS-232 port by means of PC or special-purpose personal digital assistant like the iTracPen.
Software comprises a 32-bit Windows-application running on an iTracs-server that is connected to a Stand-alone-Analyzer or a Master Analyzer depending on system configuration. The application interacts with SQL database and graphic AutoCAD. Integration with HP OpenView and other similar software solutions for LAN control is also possible. Besides the licensed software delivered in the same package with the analyzer, complimentary software is also available and can be purchased along with the control system, as required.
Among SCS available on the Russian market the iTracs solution is used under the trademark LANSense. In cable systems of the English market it is available from ITT NS&S. In October 2001 the company Molex announced it as the part of its SCS under the trademark Real Time.
PatchView system by RiT Technologies
The PatchView system was historically the first commercially produced system for structured cabling interactive control. This solution was developed by the Israeli company RiT Technologies in the middle of 1990s.
The system is similar to iTracs and includes patch panels with special-purpose cords, control modules and controlling software.
Patch panels of SMART and SMART-GIGA provide performance of Category 5e and 6, and are available shielded and unshielded as well as in options for 16-, 24, - and 32 ports. Similar to other systems they have sensors on each port, which register connection or disconnection moment of the plug of a patch cord.
A red LED provides interaction between the controlling program and the user in interactive mode when using the panel. Each outlet is equipped with this element, which is the only visible sign of the Patch View technology. LEDs can blink or stay steady. The SCS information transmission channel has two ends according to standards; therefore LEDs are switched in pairs. First, all cords should be disconnected. Two LEDs mark the disconnected cord by blinking. LEDs mark those ports that are ready for connection with a steady light. Special cords are used for communications between ports. They are made of nine-wire cable (four pairs for information transmission and controlling conductor) and terminated with 10-wire plugs (zero contact is not used). Such a customized nine-wire cable is used according to current SCS standards, which strictly inhibit parallel connections to conductors of a cable channel. If necessary, it is possible to use standard eight-wire cords with eight-pin modular plugs, as 10-pin plugs are completely compatible with them. At the same time, however, the system fails to monitor the state of ports.
The patch panel is connected to the cable scanner by a ribbon cable via controlling port sidewise on the rear surface of the panel. The cable scanner functions as the control module and presents itself as a special-purposed device with elements for fastening in 19" rack. It is accommodated in the rack together with panels. There are two types of scanners: master and satellite. Master and satellite scanners integrate into the single system via interface RS-485 by local bus. A 10Base-T port is used to exchange messages with the Cabling Control Station. Five to 10 patch panels, depending on their modification, can be linked to one cable scanner. For aesthetic purposes the scanner has connectors for jumper cable on its rear side. The Control Station remotely processes incoming messages from the scanner and issues instructions on it. A Portable control panel connected to the scanner via a dedicated port on the front panel can be used to work in equipment zone. The scanner functions automatically and starts continuous scanning of ports immediately after the power is on. The scanner sends information collected from all ports to the Control Station via standard SNMP protocol through the LAN. To control a remote device, data can be transmitted via modem or RS-232 port.
The scanner processes information collected from the panels, supports communication with the Control Station as well as issues instructions for LEDs on the panels.
It is possible to connect an optional controller to the scanner, which monitors the state of various devices installed in the rack (locks, humidity sensors and so on). The controller is produced in two options: as a full version or an auxiliary adapter. It is free from fastening elements on mounting rails in 19" rack. One controller supports a maximum of six different-purposed sensors and the issue of commands to four execution elements by means of relay contacts. It is allowable to cascade two controllers. Unlike this controller an auxiliary compact adapter supports the work of two indicators. The scanner also processes and sends to the Control Station all messages coming from sensor controller and execution elements. All incoming messages appear immediately on the display of the Control Station.
Cabling Control Station is a PC, which is the core element of the Patch View system. The PC operates on Windows-based controlling software. It supports interface-complex with system administrator, database, forms alerting commands and other messages.
Information collected by scanners is processed and is then filled in marked fields of the database of connections. Parts of the database fields contain text information, which is entered by a designer during its production and system administrators during maintenance. The database is developed according to requirements of the standard TIA/EIA-606A, and enables processing of all necessary documents required by the standard.
Evolutionary systems known under the trademarks PatchView for Enterprise and PatchView for Datacenter differ from their prototypes by functional programming capabilities, which minimize the workload for network administrator.
During 2000-2001 a number of cable systems manufacturers (TKM, Germany; Panduit, USA; Brand-Ex, England) have concluded an agreement with the company RiT on implementation of the licensed PatchView in cable systems manufactured by them. It is also known that Panduit plans to distribute this solution under the trademark Panview.
Similar to SCS the reviewed systems have a single-type hierarchic tree structure in their full configuration and can be overlapped on SCS without any considerable changes.
The general use for these solutions is as follows:
- Implementation in the form of more or less advanced but obligatory all-in-one hardware and software systems;
- Possibility to use peer and hierarchic construction principles in order to increase the number of served ports;
- Obligatory inclusion of modified patch panels, special-purposed controllers and software running from the Control Station by network as a part of regular equipment. At the same time the listed elements and their names are the same for all products and form various levels of hierarchic system. (Table 1)
Existing distinctions are displayed upon connection and disconnection of patch cords. Interactive control systems (as they exist today) offer some services, including:
- Possibility to quickly collect information about random and non-random changes in SCS structure;
- Increased protection of computing system against unauthorized access to confidential data in real time;
- Automatically support and update of databases of all connections at any level in various equipment premises;
- Support of planning changes and reconfiguration management of cable system and at the same time dramatically decrease paperwork.
Each system has its limitations resulting from the method of information reading on execution of reconnec-tion of ports. We should also note that the reviewed systems monitor configuration only for those elements of structured cabling, which are within the scope of the standards. Thus, normally they do not control (without a special modification) the state of equipment cords at the workplace, where failures and improper configurations account for many reasons of failure in a network.
The functioning principle of interactive control systems described here shows that they do not have any serious limitations for the use in optical LAN systems. The only limitation is the obligatory requirement to use only duplex modifications of optical pigtails. This factor, however, fully complies with evolutionary process of fiber-optical subsystems in modern SCS. Nevertheless, the use of a system with interactive control for optical patch devices is very rare. This factor can be explained by purely practical reasons. The optical system is more typically used as backbone cabling segments. At the beginning of 2002 there were 19" shelves by RiT of various heights for up to 96 SC and MT-RJ outlets. Shelves of 1U height for MT-RJ connectors are included in the system LANSense by ITT, which is based on the iTracs technology. Each optical port of such shelves is equipped with a sensor of connection and a LED (in products by RiT). Modified duplex optical cords complete the connections. They are based on iTracs technology and differ from the standard cords. It is okay to use common patch cords in optical shelves; however, it is impossible then to monitor the state of ports.
Comparison Analysis of Reviewed Solutions
Besides general features the reviewed solutions also possess considerable distinctions, whose value and drawbacks appear in different ways and different situations and can be considered both as benefits and drawbacks of a product depending on requirements for a specific project. We evaluate features and attributes by a number of criteria, which are more or less applied in engineering practice, including procurement and selection of type of installed SCS.
MAXIMUM NUMBER OF CONTROLLED PORTS
The solutions are placed as follows: PatchView, iPatch and iTracs. The minimum value of the parameter for the solution is 20480, i.e. all solutions can be used for an absolute majority of projects.
Currently, PatchView and iTracs differ somewhat from Avaya Communications, as they also include shelves with optical pigtails together with modular panels.
The solutions by RiT and Avaya Communications seem to be equal, as patch cords of their products are free from any exterior elements. Cords applied in the iTracs technology differ in as much as its pin contact protrudes from the protective boot.
reliability in emergency conditions with cable faults
The solutions by RiT and Cablesoft also differ from Avaya, as the first two solutions possess a control module, which immediately detects and registers interruption of the controlled ninth conductor.
iTracs is ahead of the competition, as it was initially designed for the use without any orientation on a specific SCS producer, that enables its use not only for modular panels, but also for panels of 110 type and optical switching systems after some minimum changes in their design. Besides, this solution can be implemented in existing SCS without its full shutdown when using patch panels according to a modular scheme. -
QUICK COMMERCIAL LAUNCH
Transmission of information signals and management of setup connections enable the quick commercial launch of the solution by Avaya Communication (for example, changeover to a higher category). The solution by iTracs also satisfies this parameter (but it is necessary to make sure, that controlling conductor does not impact the performance of information transmitted across the cable). The PatchView system requires a completely new design of the printed circuit board for modular panels.
A high level of unification of elements with common systems is achieved in the iPatch system, which requires the use of only modified patch panels. This provides the highest level of serviceability. Alternative solutions require extra special-purpose cords.
At present, PatchView takes a leading position in the market. Its scanners have very high computing capacity that allows controlling of multiple parameters of mounting racks and equipment rooms with the help of regular elements. Auxiliary special-purposed controllers being a part of regular system components support this function as well.
RiT and iTracs retest physical connections of ports at restoration of power supply and, if required, generate warning messages and update the database of connections and so on. Avaya reconnects after a power failure may show errors in the connection database.
Many specialists note such potential, that when using solutions by Avaya Communication and RiT users can remotely control configuration of their cable system in small offices by their own forces without the help of an authorized system administrator. This is possible because panels are equipped with LEDs to control the reconnection process. Panel logic and system administrator of the Control Station strictly control that reconnection is made correctly. It is fair to say, that this benefit is rather made for advertisement purposes, than for the practical need. The reason for that is that small offices and remote subsidiaries have low-scaled SCS and do not need often reconnection in comparison with large-scaled cable systems.
The studied material enables the following outputs: The presence of three competitive products forms a fairly new and separate SCS market segment. Existing solutions offer full hardware and software systems, which enable the cabling with interactive management in real time. All reviewed systems offer the system administrator almost the same service. The main distinctions between the systems may be defined by the use of various principles for monitoring of setup and termination of connection.
Selection of an interactive control system type should be based on multi-criteria principles and unique requirements for a specific project. The strongest distinctive feature of the PatchView system is the quality of optional service rendered. It is easier with iPatch to upgrade cabling to a higher category. The iTracs hardware can be easily adapted to SCS equipment of various manufacturers.
The systems with interactive control fully realize their benefits predominantly in major networks. At present, commercial use of these solutions in smaller scale networks may be economically infeasible.
Andrew Semenov is the project director of the networking department for the Russian system integrator and distributor "IT". This company sells its own SCS on the Russian market. He is a co-author of the book "Structured Cabling Systems" in Russian that has three editions here in Russia. The author of the case study would like to express special thanks to Vsevolod Nikolaychuk (Representative Office of RiT Technologies) and Petr Kolenko (Company Trale) for technical information.