Chapter 02ECIL AMSS Configuration 2.1 INTRODUCTION ECIL ’s Automatic Message Switching System (AMSS) is a computer-based message switching system working on store and forward principle. AMSS receives the messages from terminals connected directly to it, and also from terminals connected via other switches. It analyses the received messages for the correctness of the format and address, stores them in the memory and also on online mass-storage media and automatically retransmits the messages to its destination. While re-transmitting, AMSS keeps in view the precedence of message. In the process of re-transmitting, AMSS checks continuously for the availability of the line for the destination of message. In case the message is not as per the format or has incorrect addresses, the message is rejected and the service message is generated depending on the variety of error and sent back to the originator of the message. For supervision of the switch AMSS sends reports to the supervisory terminals about changes in status of the system and lines. AMSS generates periodical statistical and status reports for the supervisor. AMSS provides facilities to store the every day’s messages on the removable media for the long-term storage and retrieval. The AMSS accepts AFTN message format. The messages are input from message terminal equipped with user-friendly interface with graphical interface and worked under windows software environment. AMSS switch consists of redundant, fully duplicated computer. Normally one of the systems works as online and other as hot standby. Incase of failure of one system, the other system takes over automatically ensuring availability of the switch. The AMSS is configured around powerful Intel PIII- 700 MHz-1.3 GHz. microprocessor and has a high throughput capability. The operating system for the AMSS is SCO UNIX version 5.0.5 environment. The AMSS can support from 128 lines. AMSS supports a variety of line type protocols from RS232C, Telex, X.25, Frame relay, COPB, Tele-printer with speeds varying from 50 baud to 64 Kbps and character code being either 5 bit or 8 bit. For supervision and control of switch, a set of user friendly commands with online help are provided, which include service, message retrieval, and to obtain reports on request. CATC, ALLAHABAD MAY 2005 Page 1 of 8 The AMSS server is installed with Stallion card as communication controller module to serve multiple numbers of channels. This logic connects the online server to the outgoing/incoming channel in the LTU rack. Database Server (s). Uninterrupted Power Supply (UPS). Patch Panel Rack. one is configured as SYSTEM A and other as SYSTEM B./r or . ALLAHABAD MAY 2005 Page 2 of 8 .1 AMSS Server The AMSS servers are running on SCO UNIX 5. Both the AMSS servers are individually connected to parallel printers. The system generated health / activity information are printed on these printers. The Online and Hot Standby servers communicate health to each other through SOLC cards.2 Disk Switch CATC. Disk Switch. Ethernet Switch / Hub. 2. Both of the AMSS servers are installed with Switch Over Logic Control (SOLC) cards.25 / Communication Server.05 operating system. Line Termination Unit (LTU) Rack. both SOLC cards provide SOLC logic to the LTU rack.2. Communication Channel Multiplexer (CCM) Adaptor. Depending upon which server is online (SYS A or SYS B). At one time any one of the server can be made Online and the other Hot Standby. The ECIL AMSS is having two servers. This is done by running appropriate Unix Shell Scripts (. 2. Workstations / Nodes.2 SYSTEM CONFIGURATION AMSS Server (s). /h ) in respective servers.2./n or . X. Remote Printers. The ECIL AMSS setup consists of following: The schematic of AMSS setup of ECIL AMSS is given at the end of this chapter .2. The SCSI Disk 0 is housed in Disk Switch 01 and Disk 1 is housed in Disk Switch 02 respectively. Each SCSI disk and its corresponding connector are housed in a single cabinet and as a whole referred as Disk Switch. The connection of each SCSI disk with servers is shown in the following figure. Line status for each channel. ALLAHABAD MAY 2005 Page 3 of 8 .The SCSI disks are referred as DISK 0 and DISK 1. These are: • • • • • • • Ledger area Message area Incoming MCP area Outgoing MCP area Incoming Index area Outgoing Index area Journal area Ledger area Information that is needed for recovery is stored here. Each SCSI disk is logically divided into seven logical areas. Down time Break status Number of rejected messages per day Hourly incoming total Incoming total Outgoing total Peak hour incoming total Expected incoming sequence number Expected outgoing sequence number Count of SVC messages (incoming / outgoing) Incoming closed Outgoing closed Route status for each route Blocked CATC. Size of the message area depends on Maximum number of messages to be stored Average length of message. CATC.Auto diversion enabled Divert priority Status of the diverted route Number of messages in each priority queue Start and end address of each priority queue Alternate routes (diverted route) System total of incoming and outgoing messages Disk starting address and offset for Message area Incoming MCP area Outgoing MCP area Incoming Index area Outgoing Index area Status of both the disks Partial update Full update Update request Count of delayed messages in each priority Byte count of every remote channel each day Outgoing messages for 10 days Peak hour incoming for 10 days Peak hour outgoing for 10 days Previous incoming Previous outgoing Hourly outgoing total Hourly pending Hourly incoming total Message Area Incoming and outgoing messages are recorded in the message area. ALLAHABAD MAY 2005 Page 4 of 8 . Number of days the message has to be stored. stores the an index consisting of Channel number Sequence number Block number in the message area Offset Outgoing Index area. Outgoing MCP area. Size of this area depends on Maximum number of messages to be stored in the disk For each outgoing message stored in disk. Incoming Index area Size of this area depends on Maximum number of messages to be stored in the disk for each incoming message is stored in disk. ALLAHABAD MAY 2005 Page 5 of 8 . Incoming MCP area Size of this area depends on Maximum number of messages to be stored in the disk MCP of each incoming message is stored in this area. Size of this area depends on Maximum number of messages to be stored in the disk MCP of each outgoing message is stored in this area. stores the an index consisting of Channel number Sequence number Block number in the message area Offset Journal area CATC. Disk 0 and Disk 1 is divided into two partitions which are referred as File 0 and File 1. The information that is needed for recovery is stored in this Ledger Area. SYSTEM A Active Terminator SCSI Connector PCB SYSTEM B DISK SWITCH 01 SCSI CONNECTOR DISK SWITCH 02 SCSI CONNECTOR Active Terminator SCSI Connector PCB SCSI PORT SCSI DISK 0 SCSI DISK 1 SCSI PORT Motherboard Motherboard Figure: Disk Switch Configuration 2.e.Journal information is stored for each message In-time date/hours/minutes Inprefix Incoming sequence number Outtime date/hours/minutes Outprefix Outgoing sequence number Destination indicator Priority Online server stores outgoing / incoming messages on the Message Areas of both the disks for 30 days. ALLAHABAD MAY 2005 Page 6 of 8 .2. 1 of Disk 1) in sequence in the interval of 30 seconds. The Online server stores the information required for recovery on these four partitions (File 0.3 Database Server The Database Server is running on Windows NT Server 4.0 operating system. The purpose of this server is to maintain a database of transmitted/received CATC. The discussion on other areas is beyond the scope of this course.. 1 of Disk 0 & File 0. The Ledger area of each disk i. These are discussed in detail in the “ECIL AMSS System Administration Course”. hot swappable.0 operating system and having additional hardware (EICON card) to incorporate X. data is recomputed with the help of parity.2. FIC.25 Server In airports where traffic is very high it is required to send data over a high-speed line and for this purpose X. In the next cycle striped data is stored in Disk B & C and the parity on Disk A. The X.5 Workstation / Node. The advantages of using RAID are manifold.25 server is connected to X. 2. 15” color monitor.NOTAM/MET/ATC/FIC messages for which data have to be kept for more than 30days.25 server is used. In international airports where message traffic is high. Disk A Disk B Disk C The block of data to be stored is striped and stored in the Disk A and B and the corresponding parity on the Disk C in the first cycle.e. TVSE Keyboard. ALLAHABAD MAY 2005 Page 7 of 8 . and MET/NOTAM/HFRT messages with redundancy. The RAID5 configuration is based on data striping.25 communication interface. Any position wants to use ECIL AMSS must run appropriate application program (for example CATC. two button mouse and serial printer. more than one-database servers are used for storage of ATC. If any one of the disks in the array becomes unserviceable.25 line through a high-speed modem or PAD (Packet assembler and Dissembler). The RAID controller card is installed in the Database server to connect more than one SCSI disks in an array. and subsequently data is written on C & A and parity on B. The workstations are running on Windows NT Workstation 4. HFRT etc) is having a personal computer referred as Workstation or Node which consists of Main System Unit.25 server is also running on Windows NT Server 4. 2. NOTAM booking. it can be removed without affecting the functionality of the system i.2. Each position (like Supervisor.0 operating system. In the event of failure of a disk. called Redundant Array of Inexpensive/Independent Disks (RAID). This server acts as an interface between LAN of any particular airport and X. The RAID5 configuration is implemented in the application server with three 36GB disk. The X.25 line.4 X. 6 Ethernet Switch / Hub.exe for supervisor position or hfrt. The term B/C/M refers to the modes of LTU operation.2. 2. Each CCM adaptor can support up to 16 numbers of channels. over voltage protection.exe for HFRT position) on his workstation. This unit also provides line isolation.7 CCM Adaptors The CCM adaptors are used as the interface between of the Unix server and the LTU rack. LTU-B/C/M. Modem Interface (C Mode). and LTU-D.supervisor. • LTU B/C/M: The LTU B/C/M card is basically a communication interface card. b. CATC. 2. the improved client server response time can be achieved because of single collision domain. The card provides interfacing capabilities for three different interfaces namely: a. All of these LTU cards are terminated on the same back plane motherboard in the LTU rack. It works in coordination with Stallion card for multiplexing of messages through different channels. LTU-C. Terminal c. Interface (M Mode). 2. current protection etc.8 Line Termination Unit (LTU) Rack The LTU rack consists of it’s own power supply modules and three types of line termination units.2. ALLAHABAD MAY 2005 Page 8 of 8 .60 volts TP level to +/-12 volts RS 232 level and vice-versa).2. Tele-printer Interface (B Mode). which is terminated on back plane motherboard by 64-pin EURO connector. In B mode LTU B/C/M does the code conversion (ASCII to Baudot and vice-versa) as well as voltage conversion (from +/. Ethernet Switch or Hub is a central unit through which all the servers and workstations/nodes are interconnected by LAN cables. Any of the above modes can be selected. one at a time through Dipswitch selection. The advantage of using Ethernet Switch over Hub is that. LTU C only operates in C mode (RS 232 to RS 232 interfaces and also performs the functions of line isolations. Modems: Any remote computer can be connected to the ECIL AMSS using Dial Up modems.264V. c) +/. 5 Amps. The supply to AC distribution box is from AC mains. supplied by AC distribution box housed in the LTU rack. and up to a distance of 2 Kms at 19. Input to all the above modules is 176V . which AMSS server is online (SYS A or SYS B). Patch panel: The output of LTU B/C is connected to TP lines at patch panel using U LINK. LTU D card further extends this logic signals to all other LTU cards through back plane motherboard.2Kbps. Modems and Line Drivers are housed in this rack. 8 Kms at 9600 bps. 50 Hz A. current protection. which are far away from the system site.9 Patch Panel Rack The Patch panel. Each patch panel module is capable of connecting 16 channels. which is presently online to the outgoing/incoming channels and remote printers. 6 Amps.12 V DC. 6Amps.2. ALLAHABAD MAY 2005 Page 9 of 8 . The logic level of these signals depend upon. over voltage protection. d) +5 V DC. Unlike LTU B/C/M. The loop back test for the system side as well TP line side can be done by changing the position of U LINK.C. • LTU D: The SOLC cards of both the AMSS servers provide the SOLC logic signals to LTU-D card. CATC. Above dc supplies are required by LTU cards electronic circuitry and for voltage conversion.• LTU C: It is used to connect remote printers to UNIX server. Line drivers can drive the line up to a distance of 15 Kms at 300 bps. 12 Kms at 1200 bps. These logic signals then connects the SYSTEM A or SYSTEM B. Line Drivers: The line drivers are used to connect remote printers. b) –60 V DC. • LTU Rack Power Supply: The LTU rack has four redundant power supply modules a) +60 V DC. 2. 30 Amps. The rectifier is supplied by the electric utility network AC (alternating current) power . These printers are referred as Remote Printers. short circuits and overheating etc.10 Remote Printers The ECIL AMSS is incorporated with Report Printer. The ECIL AMSS is equipped with a VINITEC Alpha series UPS to supply uninterrupted AC power of high quality to the system. The remote printers are connected to UNIX server through LTU C. The inverter is protected against overloads. The UPS consists of following basic elements. The capacity of the UPS depends upon the load. Inverter. • • • Rectifier / Charger.2.The DC output of the rectifier in turn supplies the inverter and float charges the battery. Drop printers can be provided to any location through LTU C. the inverter will be supplied directly from the battery. Reject Printer: Messages rejected by the system and Channel Check and Mischeck messages are automatically printed on this printer. even when the incoming main is cut off completely.2. • • • Report Printer: System generated Hourly. CATC. A battery bank does the necessary storage of electric energy. The high-tech inverter is key to the system. ALLAHABAD MAY 2005 Page 10 of 8 . Drop Printers: As per the requirement of the station.2. Being supplied either the rectifier (or so indirectly by the mains) or the battery. it generates an uninterrupted AC output to feed the critical load. 2. Reject Printer located in supervisor position and Drop Printers located in other positions as required.11 Uninterrupted Power Supply (UPS). Battery bank. In the event of failure of the mains supply. Half hourly reports and other system information are automatically printed on this printer. ALLAHABAD MAY 2005 Page 11 of 8 .CATC. NOTAM MET HFRT BOOKING MLU AREA BRIEFING ETHERNET SWITCH OR HUB DATABASE SERVER1 (JKA) DATABASE SERVER2 (JKB) ADC/FIC SERVER (JKC) ADC/FIC SERVER (JKD) REMOTE LINES LTU RACK SYSTEM A SYSTEM B CATC. ALLAHABAD MAY 2005 Page 1 of 8 .