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This chapter describes the equipment and site requirements for installing a Cisco media gateway (MGW). The chapter contains the following sections:
Before installing your media gateway, you should consider the power and cabling requirements that must be in place at your installation site, the equipment needed for installation, and the environmental conditions your installation site must meet to maintain normal operation. This chapter guides you through the installation preparation process.
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Warning Only trained and qualified personnel should be allowed to install or replace this equipment. |
This section provides safety guidelines to help you avoid injury to yourself and avoid damage to the equipment. The following safety guidelines are recommended when working with any equipment that connects to electrical power or telephone wiring:
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Warning Before working on equipment that is connected to power lines, remove jewelry (including rings, necklaces, and watches). Metal objects will heat up when connected to power and ground and can cause serious burns or weld the metal object to the terminals. |
Follow these basic guidelines when working with any electrical equipment:
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Caution Read the installation instructions before you connect the system to its power source. |
In addition, use the guidelines that follow when working with any equipment that is disconnected from a power source, but still connected to telephone wiring or other network cabling.
Electrostatic discharge (ESD) damage, which occurs when electronic cards or components are improperly handled, can result in complete or intermittent system failures. The access server components include printed circuit boards that are fixed in metal carriers. These metal carriers provide electromagnetic interference (EMI) shielding, connectors, ejector levers, or handles to protect against ESD. Although each carrier is designed to protect the boards, an antistatic strap should be used. Remember to handle the carriers by the ejector levers, handles, and carrier edges only; never touch the circuitry or connector pins.
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Note Always tighten the panel fasteners on the Cisco 5814 dial shelf feature cards and dial shelf controller cards, and captive screws on the Cisco 7206 router shelf network processing engine and I/O controller. These screws prevent accidental removal, provide proper system grounding, and help ensure that the bus connectors are properly seated. |
The following are guidelines for preventing ESD damage:
The Cisco AS5800 access server has special safety requirements, as follows:
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Warning Two people are required to lift the AS5800 chassis. Use the handles on the chassis sides. To prevent injury, keep your back straight and lift with your legs, not your back. To prevent damage to the chassis and components, never attempt to lift the chassis with the handles on the power supplies, the filter module, or the blower assembly. These handles are not designed to support the weight of the chassis. |
Whenever you lift any heavy components manually, follow these guidelines:
The Cisco 5814 dial shelf feature cards, dial shelf controller cards, and power supplies are designed to be removed and replaced while the system is operating, without causing damage to the system.
When working with the Cisco 7206 router shelf, however, you must power down the system before removing or replacing the I/O controller and network processing engine. For more information, refer to the Cisco 7200 Series Installation and Configuration Guide that shipped with your Cisco 7206 router shelf.
The Cisco access servers and switches are designed with an environmental monitoring system that protects the system and components from potential damage from overvoltage and overtemperature conditions. To assure normal operation and avoid unnecessary maintenance, plan your site configuration and prepare your site before installation. After installation, make sure that the site maintains an ambient temperature of 32° through 104° F (0° through 40° C), and keep the area around the chassis as free from dust as is practical.
The following sections address the site environment requirements for the access server.
The Cisco servers and switches are designed to support either AC-input or DC-input power.
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Caution Never use an AC-input router shelf with a DC-input dial shelf, or the reverse; otherwise, your router could be damaged. |
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Note The color coding of the DC-input power supply leads depends on the color coding of the DC power source at your site. Typically, green or green/yellow is used for ground, black is used for +48V (return), and red or white is used for -48V. Make certain that the lead color coding you choose for the DC-input power supply matches lead color coding used at the DC power source. |
The following are guidelines for setting up the plant wiring and cabling at your site. When planning the location of the new system, consider the distance limitations for signaling, EMI, and connector compatibility, as described in the following sections.
When wires are run for a significant distance in an electromagnetic field, interference can occur between the field and the signals on the wires. This fact has two implications for the construction of plant wiring:
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Note To predict and remedy strong EMI, you might also need to consult experts in radio frequency interference (RFI). |
If you use twisted-pair cable in your plant wiring with a good distribution of grounding conductors, the plant wiring is unlikely to emit radio interference. If you exceed the recommended distances, use a high-quality twisted-pair cable with one ground conductor for each data signal, when applicable.
If wires exceed recommended distances, or if wires pass between buildings, give special consideration to the effect of a lightning strike in your vicinity. The electromagnetic pulse caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. If such problems have occurred in the past, you might want to consult experts in electrical surge suppression and shielding.
The size of your networks and the distances between connections depend on signal type and speed, and transmission media (the type of cabling used to transmit the signals). For example, standard coaxial cable has a greater channel capacity than twisted-pair cabling. The distance and rate limits in the following descriptions are the IEEE recommended maximum speeds and distances for signaling; however, you can usually get good results at speeds and distances far greater than these. For example, the recommended maximum rate for V.35 is 2 Mbps, but it is commonly used at 4 Mbps without any problems. If you understand the electrical problems that might arise and can compensate for them, you should get good results with rates and distances greater than those shown here; however, do so at your own risk.
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Note We recommend that you do not exceed specified transmission rate and distance limits. |
When preparing your site for network connections to the access server, you should consider the following:
Before installing the access server, have all additional external equipment and cables on hand, which are noted in the documentation that ships with each component. For ordering information, contact a customer service representative.
The rack-mounting hardware included with the access server is suitable for standard 19-inch, 4-post, and telco equipment racks. To easily access removable components while the system is installed in a rack, verify that you have access to the system front and rear panel areas.
Before using a particular rack, check for obstructions (such as a power strip) that could impair rack-mount installation. When mounting the router in 4-post or telco-type racks, use all the recommended screws and brackets to secure the chassis to the rack posts.
When planning your rack installation, consider the following guidelines:
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Warning To prevent bodily injury when mounting or servicing this unit in a rack, you must take special precautions to ensure that the system remains stable. The following guidelines are provided to ensure your safety: |
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Caution To prevent chassis overheating, never install your access server in an enclosed rack or room that is not properly ventilated or air conditioned. |
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Warning Care must be given to connecting units to the supply circuit so that wiring is not overloaded. |
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Caution This equipment is intended to be grounded. Ensure that the host is connected to earth ground during normal use. |
Table 2-1 lists the operating and nonoperating environmental site requirements. The following ranges are those within which the access server will continue to operate; however, a measurement that is approaching the minimum or maximum of a range indicates a potential problem. You can maintain normal operation by anticipating and correcting environmental anomalies before they approach an operating limit.
Airflow to cool the access server is from front to back in the dial shelf chassis and from right to left in the router shelf chassis (when viewing the router from the front). Adhere to all spacing requirements for proper air flow maintenance.
Temperature, ambient operating 32° F (0° C) 104° F (40° C) Temperature, ambient nonoperating and storage -4° F (-20° C) 149° F (65° C) Humidity, ambient (noncondensing) operating 10% 90% Humidity, ambient (noncondensing) nonoperating and storage 5% 95% Altitude, operating and nonoperating Sea level 10,000 ft Vibration, operating 5-200 Hz, 0.5 g (1 oct./min.) - Vibration, nonoperating 5-200 Hz, 1 g - Clearance, air intake and exhaust 24 in. (60.95 cm) -
Table 2-1: Specifications for Operating and Nonoperating Environments
Specification
Minimum
Maximum
(3050 m)
(1 oct./min.) 200-500 Hz, 2 g (1 oct./min.)
Planning a proper location for the access server and the layout of your equipment rack or wiring closet are essential for successful system operation. Equipment placed too closely together or inadequately ventilated can cause system overtemperature conditions. In addition, chassis panels made inaccessible by poor equipment placement impair system maintenance.
Follow these precautions and recommendations when planning power connections to the Cisco media gateway:
A site log provides a historical record of all actions relevant to access server operation and maintenance. Keep your site log in a common place near the system. Site log entries might include the following:
Table 2-2 shows a sample site log page. Make copies of the sample, or design your own site log, to meet the needs of your site and equipment.
| Date | Description of Action Performed or Symptom Observed | Initials |
|---|---|---|
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Posted: Thu Jun 15 14:33:11 PDT 2000
Copyright 1989 - 2000©Cisco Systems Inc.