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This chapter provides specific information about preparing your site for the Cisco 12012. Included are safety guidelines, specific preparatory information, and tools and parts required to assure a successful installation of your Cisco 12012.
Do not remove the Cisco 12012 from its shipping container until you are ready to install it. Keep the router in the shipping container to prevent accidental damage until you have determined where you will install it.
Use the unpacking documentation included with the router when you unpack the Cisco 12012. Inspect all items for shipping damage. If anything is damaged, immediately contact a customer service representative.
Sections in this chapter include the following:
Before installing your Cisco 12012, you should consider power and cabling requirements that must be in place at your installation site, the equipment you will need to install the router, and the environmental conditions your installation site must meet to maintain normal operation. This chapter guides you through the process of preparing for your router installation.
The following guidelines will help to ensure your safety and protect the equipment. This list is not inclusive of all potentially hazardous situations, so be alert.
A fully configured Cisco 12012 weighs approximately 380 lb (172 kg); it is not intended to be moved frequently. Before you install the router, ensure that your site is properly prepared so you can avoid having to move the Cisco 12012 later to accommodate power sources and network connections.
Whenever you lift any heavy assembly, follow these guidelines:
 | Caution To prevent damage, never attempt to lift or tilt the Cisco 12012 using the handles on the blower modules or on the power supplies. These handles are not designed to support the weight of the Cisco 12012. |
The line cards, redundant clock and scheduler cards, switch fabric cards, alarm card, blower modules, and redundant power supplies can be removed and replaced while the system is operating without presenting an electrical hazard or damage to the system.
Follow these basic guidelines when working with any electrical equipment:
In addition, use the guidelines that follow when working with any equipment that is disconnected from a power source, but still connected to telephone or network wiring:
Many router components are sensitive to damage from static electricity. Some components can be degraded by voltages as low as 30V. Conversely, static voltages as high as
35,000V can be generated just by handling plastic or foam packing material, or by sliding assemblies across plastic and carpets. Not exercising the proper electrostatic discharge (ESD) precautions can result in intermittent or complete component failures. To minimize the potential for ESD damage, observe the following guidelines:
| Caution For safety, periodically check the resistance value of the antistatic strap. The measurement should be between 1 and 10 megohms. |
Single-mode style line cards for the Cisco 12012 are equipped with lasers, which emit invisible radiation. Do not stare into open line card ports. Observe the following warning to prevent eye injury.
 | Warning Because invisible laser radiation may be emitted from the aperture of the port when no cable is connected, avoid exposure to laser radiation and do not stare into open apertures. |
This section provides the following site requirement guidelines that you must consider before installing the Cisco 12012:
Before installing the Cisco 12012 in telco-style or 19-inch equipment racks, consider the following general rack-mounting guidelines:
The rack-mounting hardware included with the Cisco 12012 is suitable for most 19-inch equipment racks or telco-style racks. We strongly recommend a rack-mount installation for the Cisco 12012 because of size and weight considerations.
Following are specific rack-mounting guidelines for the Cisco 12012:
Figure 2-1 shows the outer dimensions of the Cisco 12012 frame.
The Cisco 12012 air circulation system consists of two blower modules: one mounted at the top of the frame (above the upper card cage) and the other mounted at the bottom of the frame (below the power supply bay). The blower modules maintain acceptable operating temperatures for the internal components by drawing cooling air in through a replaceable air filter and circulating the air through both card cages and the power supply bays.
Observe the following guidelines when selecting a site to install the Cisco 12012:
Table 2-1 lists the operating and nonoperating environmental site requirements. The ranges listed are those within which the Cisco 12012 will continue to operate; however, a temperature measurement that is approaching a minimum or maximum indicates a potential problem. You can maintain normal operation by anticipating and correcting environmental anomalies before they approach critical values.
The environmental monitoring functionality built into the Cisco 12012 protects the system and components from potential damage from overvoltage and overtemperature conditions. To assure normal operation and avoid unplanned maintenance, plan and prepare your site before you install the router.
| Specifications | Minimum | Maximum |
|---|---|---|
| Ambient temperature, operating | 32°F (0°C) | 104°F (40°C) |
| Ambient, temperature, nonoperating and storage | -40°F (-40°C) | 149°F (65°C) |
| Ambient humidity, (noncondensing) operating | 10% relative | 90% relative |
| Ambient humidity, (noncondensing) nonoperating and storage | 5% relative | 95% relative |
| Altitude, operating and nonoperating | Sea level | 10,000 ft (3,050 m) |
| Thermal output | - | 10,640 Btu/hour (maximum) |
| Vibration, operating | 5 to 200 Hz, 0.5 g1 (1 oct/min)2 | - |
| Vibration, nonoperating | 5 to 200 Hz, 1 g (1 oct/min) 200 to 500 Hz, 2 g (1 oct/min) | - |
The Cisco 12012 can be configured with either AC-input or DC-input power supplies. The Cisco 12012 requires two AC-input power supplies or one DC-input power supply to operate. Site requirements differ depending on the type of source voltage. We recommend you follow these precautions and recommendations when planning power connections to the Cisco 12012:
| Warning AC operation requires a minimum configuration of two AC-input power supplies. |
In sites where the Cisco 12012 operates with AC-input power supplies, observe the following guidelines:
Table 2-2 lists the nominal and acceptable value ranges for source AC power.
| Specifications | Nominal Value | Acceptable Value Ranges |
|---|---|---|
| AC input voltage | 200 to 240 VAC1 | 180 to 264 VAC, single phase |
| AC input line frequency | 50/60 Hz | 47 to 63 Hz |
| AC input current | 9.5 amps (@ 200 VAC) | - |
| Label | Description | Product Number |
|---|---|---|
| North American | 208 VAC, 60 Hz AC power cord | CAB-GSR12-US= |
| Australian | 240 VAC, 50 Hz AC power cord | CAB-GSR12-AU= |
| European | 230 VAC, 50 Hz AC power cord | CAB-GSR12-EU= |
| Italian | 220 VAC, 50 Hz AC power cord | CAB-GSR12-IT= |
| United Kingdom | 240 VAC, 50 Hz AC power cord | CAB-GSR12-UK= |
In sites where the Cisco 12012 operates with DC-input power supplies, observe the following guidelines:
| Specifications | Nominal Value | Acceptable Value Ranges |
|---|---|---|
| DC input voltage | -48 VDC1 (United States)
-60 VDC (International) | -40.5 to -56 VDC (United States)
-58 to -75 VDC (International) |
| DC input current | 50 amps (@ 50 VDC) | - |
Before you connect power or turn on your Cisco 12012, we strongly recommend that you provide adequate system ground for your router. System grounding (earth) receptacles are provided on the Cisco 12012. The grounding receptacles are located between the air filter tray and the power supply bays, on the card cage assembly mounting flange. To ensure the system grounding connection that you provide is adequate, you will need the following parts:
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, electromagnetic interference (EMI), and connector compatibility, as described in the following sections.
When wires are run for any 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:
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 (EMP) caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. If you have had problems of this sort in the past, you may want to consult experts in electrical surge suppression and shielding.
Most data centers cannot resolve the infrequent but potentially catastrophic problems just described without pulse meters and other special equipment. These problems can cost a great deal of time to identify and resolve, so take precautions by providing a properly grounded and shielded environment, with special attention to issues of electrical surge suppression.
The SONET specification for fiber-optic transmission defines two types of fiber: single-mode and multimode. Modes can be thought of as bundles of light rays entering the fiber at a particular angle. Single-mode fiber allows only one mode of light to propagate through the fiber, while multimode fiber allows multiple modes of light to propagate through the fiber. Because multiple modes of light propagating through the fiber travel different distances depending on the entry angles, causing them to arrive at the destination at different times (a phenomenon called modal dispersion), single-mode fiber is capable of higher bandwidth and greater cable run distances than multimode fiber. The maximum distances for single-mode and multimode transmissions, as defined by SONET, are listed in Table 2-5. If the distance between two connected stations is greater than these maximum distances, significant signal loss can result, making transmission unreliable.
| Transceiver Type | Maximum Distance between Stations1 |
|---|---|
| Single-mode | Up to 9 miles (14.8 kilometers) |
| Multimode | Up to 1.5 miles (2.4 kilometers) |
To design an efficient optical data link, evaluate the power budget. The power budget is the amount of light available to overcome attenuation in the optical link and to exceed the minimum power that the receiver requires to operate within its specifications. Proper operation of an optical data link depends on modulated light reaching the receiver with enough power to be correctly demodulated.
Attenuation, caused by the passive media components (cables, cable splices, and connectors), is common to both multimode and single-mode transmission.
The following variables reduce the power of the signal (light) transmitted to the receiver in multimode transmission:
Attenuation is significantly lower for optical fiber than for other media. For multimode transmission, chromatic and modal dispersion reduce the available power of the system by the combined dispersion penalty (in decibels [dB]). The power lost over the data link is the sum of the component, dispersion, and modal losses. Table 2-6 lists the factors of attenuation and dispersion limit for typical fiber-optic cable.
| Single-Mode | Multimode | |
|---|---|---|
| Attenuation | 0.5 dB | 1.0 dB/km |
| Dispersion Limit | No limit | 500 MHz/km1 |
The LED used for a multimode transmission light source creates multiple propagation paths of light, each with a different path length and time requirement to cross the optical fiber, causing signal dispersion (smear). Higher order mode loss (HOL) results from light from the LED entering the fiber and being radiated into the fiber cladding. A worst-case estimate of power margin (PM) for multimode transmissions assumes minimum transmitter power (PT), maximum link loss (LL), and minimum receiver sensitivity (PR). The worst-case analysis provides a margin of error, although not all of the parts of an actual system will operate at the worst-case levels.
The power budget (PB) is the maximum possible amount of power transmitted. The following equation lists the calculation of the power budget:
The power margin calculation is derived from the power budget and subtracts the link loss, as follows:
If the power margin is positive, as a rule, the link will work.
Table 2-7 lists the factors that contribute to link loss and the estimate of the link loss value attributable to those factors.
| Link Loss Factor | Estimate of Link Loss Value |
|---|---|
| Higher order mode losses | 0.5 dB |
| Clock recovery module | 1 dB |
| Modal and chromatic dispersion | Dependent on fiber and wavelength used |
| Connector | 0.5 dB |
| Splice | 0.5 dB |
| Fiber attenuation | 1 dB/km |
After calculating the power budget minus the data link loss, the result should be greater than zero. Results less than zero may have insufficient power to operate the receiver.
For SONET versions of a line card, the signal must meet the worst case parameters listed in Table 2-8.
| Single-Mode | Multimode | |
|---|---|---|
| PT | -18.5 | -15 |
| PR | -30 | -28 |
| PB | 11.5 | 13 |
The following is an example calculation for a multimode power budget based on the following variables:
Estimate the power budget as follows:
The value of 5 dB indicates that this link would have sufficient power for transmission.
Following is an example with the same parameters as the previous example, but with a multimode link distance of 4 km:
The value of 4 dB indicates that this link would have sufficient power for transmission; however, due to the dispersion limit on the link (4 km x 155.52 MHz > 500 MHzkm), this link would not work with multimode fiber. In this case, single-mode fiber would be the better choice.
The single-mode signal source is an injection laser diode. Single-mode transmission is useful for longer distances because there is a single transmission path within the fiber and smear does not occur. In addition, chromatic dispersion is also reduced because laser light is essentially monochromatic.
The maximum overload specification on the single-mode receiver is -14 dBm. The single-mode receiver can be overloaded when using short lengths of fiber because the transmitter can transmit up to -8 dB. The receiver could be overloaded at -14 dB, but no damage will result. To prevent overloading the receiver connecting short fiber links, insert a 5 to 10 dB attenuator on the link between any single-mode SONET transmitter and the receiver.
The following example of a single-mode power budget is of a two buildings, 11 kilometers apart, connected through a patch panel in an intervening building with a total of 10 connectors.
Estimate the power budget as follows:
The value of 1 dB indicates that this link would have sufficient power for transmission and is not in excess of the maximum receiver input power.
Statistical models more accurately determine the power budget than the worst-case method. Determining the link loss with statistical methods requires accurate knowledge of variations in the data link components. Statistical power budget analysis is beyond the scope of this document. For further information, refer to UNI Forum specifications, ITU-T standards, and your equipment specifications.
The Cisco 12012 is designed to be installed with a minimum number of tools. The following are required tools:
To unpack your Cisco 12012, use the unpacking instructions in the document Cisco 12012 Unpacking Instructions posted on the outside of the shipping container.
If packing material is lost or damaged, the Cisco 12012 packing materials are available as an orderable item; use Product Number PKG-GSR12=.
Check the contents of the shipping packaging and verify that the following are included with your shipment:
If you do not receive everything you ordered, contact a customer service representative for assistance.
A site log provides a historical record of all actions relevant to the Cisco 12012 operation and maintenance. Keep your site log in a common place near the router where anyone who performs tasks has access to it.
Site log entries might include the following:
Table 2-9 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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