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Before installing your Cisco 12016 Gigabit Switch Router (GSR), 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. Included are safety guidelines, specific preparatory information, and tools and parts required to assure a successful installation of your Cisco 12016 GSR.
Use the unpacking documentation included with the GSR when you unpack the it. Inspect all items for shipping damage. If anything is damaged, contact a Cisco customer service representative immediately. Also, do not remove the Cisco 12016 GSR 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.
Sections in this chapter include the following:
 | Warning Only trained and qualified personnel should be allowed to install, replace, or service this equipment. |
The following guidelines will help to ensure your safety and protect the equipment. This list does not include every potentially hazardous situation, so be alert.
| Warning Do not attempt to lift the chassis with the handles on the back and sides of the chassis. These handles are not designed to support the weight of the chassis, and should be used only to steady and guide the chassis while it is being inserted into or removed from an equipment rack. To reduce the risk of damage to the chassis and serious bodily injury, do not use these handles to lift or support the chassis. |
Whenever you lift any heavy or awkward equipment, follow these precautions to avoid injury to yourself or damage to the equipment:
The line cards, redundant clock and scheduler cards, switch fabric cards, alarm cards, blower modules, and redundant power supplies can be removed and replaced while the router is operating without presenting an electrical hazard or causing damage to the router.
Follow these basic guidelines when working with any electrical equipment:
In addition, observe the following guidelines 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 ESD-preventive strap. The measurement should be between 1 and 10 megohms. |
| 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 12016 GSR:
The Cisco 12016 GSR can be mounted in most two-post, four-post, or telco-type 19-inch equipment racks that comply with the Electronics Industries Association (EIA) standard for equipment racks (EIA-310-D). The rack must have at least two posts with mounting flanges on which to mount the Cisco 12016 GSR chassis. The distance between the center lines of the mounting holes on the two mounting posts must be 18.31 inches ± 0.06 inches (46.50 cm ± 0.15 cm). Figure 2-2 shows typical two-post, four-post, and telco-type equipment racks.
Figure 2-2a shows a free-standing, enclosed cabinet with two mounting posts in the front. The Cisco 12016 GSR should not be installed in any type of enclosed cabinet, because the Cisco 12016 GSR requires an unobstructed flow of cooling air to maintain acceptable operating temperatures for its internal components. Installing the Cisco 12016 GSR in an enclosed cabinet---even with the front and back doors removed---could disrupt the air flow, trap heat next to the chassis, and cause an overtemperature condition inside the router.
Figure 2-2b shows a free-standing, four-post open rack with two mounting posts in the front and two mounting posts in the back. The mounting posts in this type of rack are often adjustable, so that the rack-mounted unit can be positioned within the depth of the rack rather than flush-mounted with the front of the rack.
Figure 2-2c shows a telco-type rack. The telco-type rack is an open frame consisting of two posts tied together by a cross-bar at the top and a floor stand at the bottom. This type of rack is usually secured to the floor and sometimes to an overhead structure or wall for stability. The Cisco 12016 GSR chassis can be installed in the telco-type rack either in a front-mounted position or a center-mounted position. (See Figure 2-3.)
In the front-mounted position, the chassis rack-mounting flanges are secured directly to the rack posts. In the center-mounted position, a set of optional center-mount brackets are secured to the rack posts and the chassis rack-mounting flanges are then secured to the center-mount brackets. The center-mounted position moves the center of gravity of the chassis closer to the vertical axis of the rack posts, which adds to the security and stability of the rack installation.
The rack-mounting hardware included with the Cisco 12016 GSR is suitable for most 19-inch equipment racks or telco-style frames.
Figure 2-4 shows the footprint and outer dimensions of the Cisco 12016 GSR chassis.
To help maintain trouble-free operation, consider the following precautions when planning your rack installation:
Cooling air is circulated through the Cisco 12016 GSR chassis by two blower modules. One blower module is inserted in a bay at the top of the chassis, above the upper card cage; the second is inserted in a bay at the bottom of the chassis, below the lower card cage.
The blower modules maintain acceptable operating temperatures for the internal components by drawing cooling air in through a replaceable air filter in front of the middle card cage and circulating the air through all three card cages.
In the power shelf, each power module is also equipped with a fan that draws cooler air into the front of the power module and forces warmer air out of the back of the power shelf.
Observe the following guidelines when selecting a site to install the Cisco 12016 GSR:
For a list of the operating and nonoperating environmental site requirements, refer to Table 1-7 in the "Product Overview" chapter. The ranges listed in Table 1-7 are those within which the Cisco 12016 GSR 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 12016 GSR protects the router 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.
The Cisco 12016 GSR can be configured with either an AC-input power subsystem or a DC-input power subsystem. Site power requirements differ depending on the source voltage used. Follow these precautions and recommendations when planning power connections to the router:
| Caution A Cisco 12016 GSR must be operated with all of its power modules installed at all times for electromagnetic compatibility (EMC). |
For a list of the nominal and acceptable value ranges for source AC power, refer to Table 1-5 in the "Product Overview" chapter. At sites where the Cisco 12016 GSR is equipped with an AC-input power shelf and power supplies, follow these guidelines:
| Label | Description | Product Number |
|---|---|---|
North America | 20A, 250 VAC | CAB-GSR16-US= |
Australia, New Zealand | 15A, 250 VAC | CAB-GSR16-AU= |
Europe, Argentina, Brazil | 16A, 250 VAC | CAB-GSR16-EU= |
Italy | 16A, 250 VAC | CAB-GSR16-IT= |
United Kingdom | 13A, 250 VAC (13A replaceable fuse) | CAB-GSR16-UK= |
For a list of the nominal and acceptable value ranges for source DC power, refer to Table 1-6 in the "Product Overview" chapter. At sites where the Cisco 12016 GSR is equipped with a DC-input power supply shelf and power entry modules, observe the following guidelines:
Figure 2-7 shows a typical source DC power distribution scheme. It shows two power cables attached to the DC-input power lugs for power shelf bay B1 (far right bay of the DC-input power shelf when looking at the back panel).
The color coding of the source DC power cable leads depends on the color coding of the site DC power source. Typically, green or green and yellow indicate that the cable is a ground cable. Because there is no color code standard for the source DC wiring, you must ensure that the power cables are connected to the DC-input power shelf terminal studs in the proper positive (+) and negative (-) polarity. In some cases, the source DC cable leads might have a positive (+) or a negative (-) label. This is a relatively safe indication of the polarity, but you must verify the polarity by measuring the voltage between the DC cable leads. When making the measurement, the positive (+) lead and the negative (-) lead must always match the (+) and (-) labels on the power shelf.
Even though the Cisco 12016 GSR chassis requires a safety earth ground connection as part of the power cabling to the power shelf, we strongly recommend that you connect the central office ground system or interior equipment grounding system to the supplemental bonding and grounding receptacles on the Cisco 12016 GSR chassis. Two receptacles are located on top of the power interface panel on the back of the chassis (see Figure 2-8) and two receptacles are located on the front flanges of the chassis, near the lower corners of the switch fabric card cage (see Figure 2-9). Each of these receptacles consists of a round bolt hole and an elongated bolt hole, surrounded by an area of bare metal.
To ensure a satisfactory supplemental ground connection, 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 router, consider the distance limitations for signaling, electromagnetic interference (EMI), and connector compatibility, as described in the following sections.
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 GRP has two EIA/TIA-232 ports: a DCE-mode console port and a DTE-mode auxiliary port. The console port is a DB-25 receptacle for connecting a data terminal, which you need to perform the initial configuration of the router. The auxiliary port is a DB-25 plug for connecting a modem or other DCE device---such as a channel service unit/data service unit (CSU/DSU) or other router---to the Cisco 12016 GSR. (See Figure 2-10.) This section contains connection equipment and pinout information for the GRP console and auxiliary ports.
The console port on the GRP is a DB-25 receptacle DCE interface for connecting a DTE terminal device to the Cisco 12016 GSR. Both Data Set ready (DSR) and Data Carrier Detect (DCD) signals are active when the router is running. The console port does not support modem control or hardware flow control. The console port requires a straight-through EIA/TIA-232 cable. Table 2-2 lists the signals used on this port.
| Pin | Signal | Direction | Description |
|---|---|---|---|
1 | GND | --- | Shield Ground |
2 | TxD | <--- | Transmit Data (from DTE) |
3 | RxD | ---> | Receive Data (to DTE) |
6 | DSR | ---> | Data Set Ready (always on) |
7 | GND | --- | Signal Ground |
8 | DCD | ---> | Data Carrier Detect (always on) |
20 | DTR | <--- | Data Terminal Ready |
The auxiliary port on the GRP is a DB-25 plug DTE port for connecting a modem or other DCE device (such as a CSU/DSU or other router) to the Cisco 12016 GSR. The port is located next to the console port on the GRP faceplate. The auxiliary port supports hardware flow control and modem control. Figure 2-10 shows an example of a modem connection. Table 2-3 lists the signals used on the auxiliary port.
| Pin | Signal | Direction | Description |
|---|---|---|---|
1 | GND | --- | Shield Ground |
2 | TxD | ---> | Transmit Data (to DCE) |
3 | RxD | <--- | Receive Data (from DCE) |
4 | RTS | ---> | Request To Send (used for hardware flow control) |
5 | CTS | <--- | Clear To Send (used for hardware flow control) |
6 | DSR | <--- | Data Set Ready |
7 | GND | --- | Signal Ground |
8 | DCD | <--- | Carrier Detect (used for modem control) |
20 | DTR | ---> | Data Terminal Ready (used for modem control only) |
22 | RING | <--- | Ring |
The GRP Ethernet port has two physical connectors. One is an RJ-45 media-dependent interface (MDI) receptacle; the other is a 40-pin, D-shell type media-independent interface (MII) receptacle. (See Figure 2-11.) You can use one or the other, but not both at the same time. Two LEDs on the GRP faceplate show which Ethernet receptacle is active.
Each connection supports IEEE 802.3 and IEEE 802.3u interfaces compliant with the 10BaseT and 100BaseTX standards. The transmission speed of the Ethernet port is set through an auto-sensing scheme on the GRP. The speed is determined by the network to which the Ethernet interface is connected, and is not user-configurable. Moreover, even at the auto-sensed data transmission rate of 100 Mbps, the Ethernet port provides maximum usable bandwidth of less than 100 Mbps. Expect a maximum usable bandwidth of approximately 20 Mbps when using either the MII or RJ-45 connection.
The GRP Ethernet port does not provide external routing functions. Its primary roles are to act as a Telnet port into the Cisco 12000 series router and to boot or access Cisco IOS software images over a network to which the GRP Ethernet port is directly connected.
Figure 2-12 shows an example of the Ethernet port in use. In this example, you cannot access Network 2.0.0.0 from the Ethernet port (E0) on the GRP in router A. You can access only the hosts and router C, which are in Network 1.0.0.0. (See dotted arrows in Figure 2-12.)
To access Network 2.0.0.0 from router A, you must use an interface port on one of your line cards (in this example, a packet-over-SONET line card in Router A), to go through router B, through router C, and into Network 2.0.0.0. (See solid arrows in Figure 2-12.)
| Warning Ports labeled "Ethernet," "10Base-T," "Token Ring," "Console," and "AUX" are safety extra-low voltage (SELV) circuits. SELV circuits should only be connected to other SELV circuits. |
The GRP RJ-45 Ethernet connection does not require an external transceiver. Figure 2-13 shows the pin orientation of the RJ-45 receptacle on the Ethernet port and the modular cable plug. Table 2-4 lists the signals used on the RJ-45 receptacle. Category 5 UTP cables are not available from Cisco Systems, but are available from commercial cable vendors.
| Pin | Signal |
|---|---|
1 | TxD+ |
2 | TxD- |
3 | RxD+ |
4 | Termination Network |
5 | Termination Network |
6 | RxD- |
7 | Termination Network |
8 | Termination Network |
When connecting the GRP RJ-45 port to a hub or repeater, use the straight-through cable pinout shown in Figure 2-14. When connecting two GRPs back-to-back, use the crossover cable pinout shown in Figure 2-15.
The GRP MII Ethernet connection requires an external physical sublayer (PHY) and an external transceiver that permits connection to multimode fiber for 100BaseFX or 100BaseT4 physical media. Depending on the type of media you use between the MII receptacle and your switch or hub, the network side of your 100-Mbps transceiver should be appropriately equipped with fiber-optic SC-type or ST-type connectors, coaxial cable BNC connectors, and so forth. Figure 2-16 shows the shape and pin orientation of the female MII receptacle on the GRP. Table 2-5 lists the signals used on the MII receptacle.
The MII receptacle uses 2-56 screw-type locks, called jackscrews (shown in Figure 2-16), to secure the cable or transceiver to the MII port. MII cables and transceivers have knurled thumbscrews that you fasten to the jackscrews on the MII connector and tighten with your fingers. Use the jackscrews to provide strain relief for your MII cable.
| Pin1 | In | Out | Input/Output | Description |
|---|---|---|---|---|
14-17 | - | Yes | - | Transmit Data (TxD) |
12 | Yes | - | - | Transmit Clock (Tx_CLK)2 |
11 | - | Yes | - | Transmit Error (Tx_ER) |
13 | - | Yes | - | Transmit Enable (Tx_EN) |
3 | - | Yes | - | MII Data Clock (MDC) |
4-7 | Yes | - | - | Receive Data (RxD) |
9 | Yes | - | - | Receive Clock (Rx_CLK) |
10 | Yes | - | - | Receive Error (Rx_ER) |
8 | Yes | - | - | Receive Data Valid (Rx_DV) |
18 | Yes | - | - | Collision (COL) |
19 | Yes | - | - | Carrier Sense (CRS) |
2 | - | - | Yes | MII Data Input/Output (MDIO) |
22-39 | - | - | - | Common (ground) |
1, 20, 21, 40 | - | - | - | +5.0 volts (V) |
| 1Any pins not indicated are not used. 2Tx_CLK and Rx_CLK are provided by the external transceiver. |
Table 2-6 lists the cabling specifications for 100-Mbps transmission over UTP and STP cables.
| Parameter | RJ-45 | MII |
|---|---|---|
Cable specification | Category 3, 4, or 5, 150-ohm UTP or STP, or multimode optical fiber | |
Maximum cable length | --- | 1.64 ft (0.5 m) (MII-to-MII cable4) |
Maximum segment length | 328 ft (100 m) for 100BaseTX | 3.28 ft (1 m)5 or 1,312 ft (400 m) for 100Base-FX |
Maximum network length | 656 ft (200 m)5 (with 1 repeater) | - |
| 1EIA/TIA-568 or EIA-TIA-568 TSB-36 compliant. 2Cisco Systems does not supply Category 5 UTP RJ-45 or 150-ohm STP MII cables or MII transceivers. These items are available commercially. 3AWG = American Wire Gauge. This gauge is specified by the EIA/TIA-568 standard. 4This is the cable between the MII port on the GRP and the appropriate transceiver. 5This length is specifically between any two stations on a repeated segment. |
Table 2-7 lists IEEE 802.3u physical characteristics for 100BaseTX.
| Parameter | 100BaseTX |
|---|---|
Data rate (Mbps) | 100 |
Signaling method | Baseband |
Maximum segment length (meters) | 100 m between DTE and repeaters |
Media | Category 5 UTP (for RJ-45) or MII |
Topology | Star/hub |
Each alarm card has one 25-pin D-sub connector, labeled ALARM, on the alarm card faceplate. (See Figure 2-17.) This connector can be used to connect the router to an external site alarm maintenance system so that any critical, major, and minor alarms generated in the Cisco 12016 GSR also energize alarm relays on the alarm card and activate the external site alarm. The alarm relay contacts on the alarm card consist of standard common, normally open, and normally closed relay contacts that are wired to the pins on the connector labeled ALARM. Table 2-8 lists the pin-to-signal correspondence between the connector pins and the alarm card relay contacts.
| Pin Group | Common | Normally Open | Normally Closed |
|---|---|---|---|
Critical audible alarm | 2 | 1 | 14 |
Major audible alarm | 16 | 3 | 15 |
Minor audible alarm | 5 | 4 | 17 |
Critical visual alarm | 19 | 6 | 18 |
Major visual alarm | 8 | 7 | 20 |
Minor visual alarm | 22 | 9 | 21 |
Alarm input | 13 | 25 | - |
| Warning The ports labeled "Ethernet," "10BaseT," "Token Ring," "Console," and "AUX" are safety extra-low voltage (SELV) circuits. SELV circuits should only be connected to other SELV circuits. |
The SONET specification for fiber-optic transmission defines two types of fiber:
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, they arrive at the destination at different times (a phenomenon called modal dispersion). Consequently, 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 2-9. 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 mi (14.8 km) |
Multimode | Up to 1.5 mi (2.4 km) |
| 1Table 2-9 gives typical results. Use the power budget calculations below to determine the actual distances. |
The first step in designing an efficient fiber-optic data link is to 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 a fiber-optic 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. Attenuation is significantly lower for optical fiber than for other media.
The following variables reduce the power of the signal (light) transmitted to the receiver in multimode transmission:
For multimode transmission, chromatic and modal dispersion reduce the available power of the system by the combined dispersion penalty, measured in decibels (dB). The power lost over the data link is the sum of the component, dispersion, and modal losses. Table 2-10 lists the factors of attenuation and dispersion limit for typical fiber-optic cable.
| Single-Mode | Multimode | |
|---|---|---|
Attenuation | 0.5 dB/km | 1.0 dB/km |
Dispersion limit | No limit | 500 MHz/km1 |
| 1The product of bandwidth and distance must be less than 500 MHz/km. |
The LED used as 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, or 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:
As a rule of thumb, when the power margin is positive, the link will work.
Table 2-11 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 2-12.
| Single-Mode | Multimode | |
|---|---|---|
PT | -18.5 | -15 |
PR | -30 | -28 |
PB | 11.5 | 13 |
The following is an example of a calculation for a multimode power budget based on these variables:
Estimate the power budget as follows:
The value of 5 dB indicates that this link would have sufficient power for transmission.
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 smearing does not occur. In addition, chromatic dispersion is 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 for a link between two buildings, 11 kilometers apart, connected through a patch panel in an intervening building. There is 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.
Site log entries might include the following:
The following page shows a sample site log page. You can make copies of the sample or design your own site log page to meet the needs of your site and equipment.
| Date | Description of Action Performed or Symptoms Observed | Initials |
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Posted: Mon Jun 5 13:45:15 PDT 2000
Copyright 1989 - 2000©Cisco Systems Inc.