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This chapter describes the PA-A3 Enhanced ATM port adapter and contains the following sections:
The PA-A3 port adapter (see Figure 1-1 through Figure 1-3) is a generation of single-width, single-port, ATM, Peripheral Component Interconnect (PCI)-based port adapters. The PA-A3 is supported in the Catalyst RSM/VIP2, Cisco 7100 series, Cisco 7200 series, and Cisco uBR7200 series routers, and the VIP2 and VIP4 in Cisco 7000 series and Cisco 7500 series routers.
The PA-A3 port adapters include five hardware versions that support the following standards-based physical interfaces:
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Note To allow a full view of the port adapter faceplate detail, port adapter handles are not shown. |
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Note The PA-A3-OC3MM and the PA-A3-OC3SML have faceplates identical to that of the PA-A3-OC3SMI shown in Figure 1-2. |
There are no restrictions on slot locations or sequence; you can install a PA-A3 in any available port adapter slot.
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Note Traffic from multiple ATM network interfaces could theoretically exceed the bandwidth of the CyBus (VIP2, VIP4, and Catalyst RSM/VIP2 only). This would cause packets to be dropped. There is no physical limit to the number of VIP2 (or VIP4) and ATM PA-A3 combinations that can be installed in the same Cisco 7500 series router up to the total that the chassis supports. (For example, a Cisco 7513 can physically have up to 11 VIP2s or VIP4s.) However, the Cisco 7500 series backplane bandwidth is finite; if you install three or more VIP2 (or VIP4) and ATM PA-A3 combinations, you need to thoroughly understand the Cisco 7500 series router bandwidth characteristics. |
The PA-A3 supports the following features:
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Note Future Cisco IOS software releases will support ABR. The PA-A3 hardware supports ABR; however, this ATM class of service requires that the feature be supported in software to be operational. |
The PA-A3 supports the following protocols, services, and ATM-specific software:
The PA-A3 complies with the environmental specifications and agency approvals listed in Table 1-1.
| Specification | Description |
|---|---|
| Environmental | |
Operating temperature | 50 to 104F (10 to 40C) |
Humidity | 0 to 90%, noncondensing |
| Regulatory Compliance |
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Compliance:
| CE Marking UL 1950, CSA-C22.2 No. 950, EN 60950, IEC 950, TS 00, AS/NZS 3260 FCC Class A (47 CFR, Part 15), EN 55022, Class B and VCCI Class B, AS/NZS 3590, Class B |
The PA-A3, shown in Figure 1-4, has one row of three status LEDs and one enabled LED.
After system initialization, the enabled LED goes on, indicating that the port adapter has been enabled for operation.
The following conditions must be met before the PA-A3 is enabled:
If any of these conditions are not met, or if the initialization fails for other reasons, the enabled LED does not go on.
Table 1-2 lists LED colors and indications.
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| LED Label | Color | State | Function |
|---|---|---|---|
ENABLED | Green | On | Indicates that the PA-A3 is enabled for operation. |
RX CELLS | Green | On | Indicates that the PA-A3 has received an ATM cell. |
RX CARRIER | Green | On | Indicates that the PA-A3 has detected a carrier on the receiver cable. For a fiber-optic interface, this means that light is detected, and a valid frame is detected. |
RX ALARM | Red | On | Indicates that the PA-A3 has detected an alarm condition. |
The PA-A3 interfaces are full duplex. You must use the appropriate ATM interface cable to connect the PA-A3 port adapter with an external ATM network.
Table 1-3 summarizes the PA-A3 interface types, connectors, and cables.
| Interface | Rate | Connector Type | Cable Type | ITU-T G.957 Standard | Bellcore GR-253 Standard | Wavelength | Maximum Distance |
|---|---|---|---|---|---|---|---|
T3 | 44.736 Mbps | BNC | Coaxial | --- | --- | --- | 450 ft (137.2 m) |
E3 | 34.368 Mbps | BNC | Coaxial | --- | --- | --- | 1250 ft (381 m) |
OC-3c/STM-1 multimode | 155.52 Mbps | SC | 62.5/125 microns multimode | Intra-office STM-1 I-1 | Short-reach OC-3c | 1310 nm | 1.2 mi (2 km) |
OC-3c/STM-1 single-mode intermediate reach | 155.52 Mbps | SC | 9 microns | Short-haul STM-1 S-1.1 | Intermediate- reach OC-3c | 1310 nm | 9.3 mi (15 km) |
OC-3c/STM-1 single-mode long reach | 155.52 Mbps | SC | 9 microns | Long-haul STM-1 L-1.1 | Long-reach OC-3c | 1310 nm | 24.8 mi (40 km) |
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Note The ATM port on the PA-A3 is considered a data terminal equipment (DTE) device. |
The PA-A3-T3 and PA-A3-E3 port adapters use a 75-ohm coaxial interface cable to connect your router to an ATM T3 or E3 network. The coaxial cables (see Figure 1-5) conform to EIA/TIA-612 and EIA/TIA-613 specifications, and they have BNC connectors. The T3 and E3 ports on the PA-A3 are considered DTE devices.
A single PA-A3-T3 or PA-A3-E3 contains one ATM T3 or E3 port that consists of two connectors: receive and transmit. The Cisco-supplied 75-ohm coaxial cable (Part Number CAB-ATM-T3/E3) has two BNC connectors that attach to the T3 or E3 port receptacles.
The T3/E3 75-ohm coaxial cable, which comes with attached ferrite bead (see Figure 1-5), is available from Cisco in five different lengths: 10, 25, 50, 75, and 100 feet (3.04, 7.62, 15.24, 22.86, and 30.48 meters). The typical maximum distance between stations for T3 transmissions is 450 feet (137.2 meters) and for E3 transmissions is 1300 feet (396 meters).
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Note To ensure compliance with electromagnetic interference (EMI) and European certification standards for emission control (EN55022/CISPR22 Class B for radiated emission levels), the Tx and Rx cables should be tied together along their entire length, and ferrite beads should be installed on each cable near the Tx and Rx connectors. |
The PA-A3-T3 and PA-A3-E3 provide an interface to ATM switching fabrics for the bidirectional transmission and reception of data at rates of up to 45 Mbps (for T3) and 34 Mbps (for E3).
The PA-A3-OC3 port adapters provide an interface to ATM switching fabrics for transmitting and receiving data at rates of up to 155 Mbps bidirectionally. The PA-A3-OC3 port adapters connect to the SONET/SDH 155-Mbps multimode or single-mode optical fiber. The OC-3c port on the PA-A3 is considered a DTE device.
For SONET/SDH multimode and SONET/SDH single-mode connections, use one duplex SC connector (see Figure 1-6) or two simplex SC connectors (see Figure 1-7). The SC connector is shipped with removable dust covers on each connector.
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Note For information on SONET specifications for fiber-optic transmissions, understanding power budget, and assistance with approximating the power margin for multimode and single-mode transmissions, see the "Fiber-Optic Transmission Specifications" section. |
An OC-3c ATM interface cable, which is used to connect your router to an external data service unit (DSU) (an ATM network), is available for use with the PA-A3-OC3 port adapters.
Cables can be obtained from the following cable vendors:
Single-mode and multimode cables should perform to the specifications listed in Table 1-4.
ISO/IEC 9314-3 1.2 miles (2 km) all cables in a connection, end to end 62.5-micron core with an optical loss of 0-9 dB, or 50-micron core with an optical loss of 7 dB IEC 793-2 24.8 mi (40 km) for SML and 9.3 mi (15 km) for SMI 9-micron core ANSI/TIA/EIA-492CAAA 24.8 mi (40 km) for SML and 9.3 mi (15 km) for SMI 9-micron core
Table 1-4: Fiber-Optic Cable Specifications
Standard
Maximum Path Length
Cabling
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Note A single fiber link should not mix 62.5- and 50-micron cable. |
This section describes the SONET specifications for fiber-optic transmissions, defines the power budget, and helps you approximate the power margin for multimode and single-mode transmissions. This section includes the following subsections:
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, whereas 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 typical maximum distances for single-mode and multimode transmissions, as defined by SONET, are in Table 1-5. If the distance between two connected stations is greater than this maximum distance, significant signal loss can result, making transmission unreliable.
| Transceiver Type | Maximum Distance Between Stations1 |
|---|---|
Single-mode long reach (SML) | Up to 24.8 miles (40 kilometers) |
Single-mode intermediate reach (SMI) | Up to 9.3 miles (15 kilometers) |
Multimode (MM) | Up to 1.2 miles (2 kilometers) |
| 1Table 1-5 gives typical results. Use the power budget calculations described in the following sections to determine the actual distances. |
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 (dB). The power lost over the data link is the sum of the component, dispersion, and modal losses.
Table 1-6 lists the factors of attenuation and dispersion for typical fiber-optic cable.
| Limits | Single Mode | Multimode |
|---|---|---|
Attenuation | 0.5 dB/km | 1.0 dB/km |
Dispersion | No limit | 500 MHz/km1 |
| 1The product of bandwidth and distance must be less than 500 MHz/km. |
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; 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 minus the link loss, as follows:
If the power margin is positive, as a rule, the link will work.
Table 1-7 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 you calculate the power budget minus the data link loss, the result should be greater than zero. Circuits whose results are less than zero may have insufficient power to operate the receiver.
The SONET specification requires that the signal must meet the worst-case parameters listed in Table 1-8.
| Single Mode (SML) | Single Mode (SMI) | Multimode | |
|---|---|---|---|
PT | -5 dBm | -15 dBm | -20 dBm |
PR | -34 dBm | -31 dBm | -30 dBm |
PB | 29 dBm | 16 dB | 10 dB |
The following is a sample multimode power budget calculated based on the following variables:
Estimate the power budget as follows:
The positive value of 2 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 1 dB indicates that this link would have sufficient power for transmission. But due to the dispersion limit on the link (4 km x 155.52 MHz > 500 MHz/km), 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 receiver for single-mode intermediate reach (SMI) cannot be overloaded by the SMI transmitter and does not require a minimum fiber cable length or loss. The maximum receive power for single-mode long reach (SML) is -10 dBm, and the maximum transmit power is 0 dBm. The SML receiver can, therefore, be overloaded when short lengths of fiber are used. Overloading the receiver will not damage the receiver but can cause unreliable operation. To prevent overloading an SML receiver connected with short fiber links, insert a minimum 10-dB attenuator on the link between any single-mode long-reach transmitter and the receiver.
The following example of a single-mode power budget assumes two buildings, 8 kilometers apart, connected through a patch panel in an intervening building with a total of 12 connectors.
Estimate the power budget as follows:
The value of 6 dB indicates that this link would have sufficient power for transmission and does not exceed 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 following publications contain information on determining attenuation and power budget:
This section discusses port adapter slot locations on the supported platforms. The illustrations that follow summarize slot location conventions on each platform.
The Catalyst RSM/VIP2 can be installed in any slot except the top slots, which contain the supervisor engine modules. The Catalyst RSM/VIP2 in a Catalyst 5000 family switch does not use interface processor slot numbering; therefore, slots are not numbered in Figure 1-8. The PA-A3 can be installed into either port adapter slot 0 or 1 on a Catalyst RSM/VIP2. Figure 1-8 shows a Catalyst RSM/VIP2 with two port adapters installed.
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Note The Catalyst 5500 switch has 13 slots. Slot 1 is reserved for the supervisor engine module. If a redundant supervisor engine module is used, it would go in slot 2; otherwise, slot 2 can be used for other modules. Slot 13 is a dedicated slot, reserved for the ATM Switch Processor (ASP) module. Refer to the Catalyst 5000 Series Route Switch Module Installation and Configuration Note for any additional slot restrictions for the Catalyst RSM/VIP2. |
The PA-A3 can be installed in port adapter slot 3 in Cisco 7120 series routers, and in port adapter slot 4 in Cisco 7140 series routers. Figure 1-9 shows a Cisco 7120 with a port adapter installed in slot 3. Figure 1-10 shows a Cisco 7140 with a port adapter installed in slot 4.
Figure 1-11 shows a Cisco 7206 with port adapters installed. In the Cisco 7206 (including the Cisco 7206 and Cisco 7206VXR as router shelves in a Cisco AS5800 Universal Access Server), port adapter slot 1 is in the lower left position, and port adapter slot 6 is in the upper right position. (The Cisco 7202 and Cisco 7204 are not shown; however, the PA-A3 can be installed in any available port adapter slot.)
Figure 1-12 shows the slot numbering of port adapters in a Cisco uBR7200 series router. The port adapter slots are numbered slot 1 and slot 2 for the Cisco uBR7246 and Cisco uBR7246 VXR and slot 1 for the Cisco uBR7223. (Slot 0 is always reserved for the Fast Ethernet port on the I/O controller---if present.)
Figure 1-13 shows a partial view of a VIP motherboard with installed port adapters. With the motherboard oriented as shown in Figure 1-13---with the port adapter faceplates facing you---the left port adapter is in port adapter slot 0 and the right port adapter is in port adapter slot 1. (The slot numbering is the same for the Catalyst RSM/VIP2.) The slots are always numbered 0 and 1.
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Note In the Cisco 7000, Cisco 7507, Cisco 7513, and Cisco 7576 routers, the VIP2 and VIP4 are installed vertically. In the Cisco 7010 and Cisco 7505 routers, the VIP2 and VIP4 are installed horizontally. |
Figure 1-14 shows a VIP2 or VIP4 installed in an interface processor slot of a Cisco 7505 router.
This section describes how to identify the interface address of the PA-A3 in supported platforms. Interface addresses specify the actual physical location of each interface on a router or switch.
The interface on the PA-A3 installed in a router or switch maintains the same address regardless of whether other port adapters are installed or removed. However, when you move a port adapter to a different slot, the first number in the interface address changes to reflect the new port adapter slot number.
The interface on a PA-A3 installed in a VIP2 or VIP4 maintains the same address regardless of whether other interface processors are installed or removed. However, when you move a VIP2 or VIP4 to a different slot, the interface processor slot number changes to reflect the new interface processor slot.
Table 1-9 explains how to identify interface addresses.
| Platform | Interface Address Format | Numbers | Syntax |
|---|---|---|---|
Catalyst RSM/VIP2 in | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 0 or 1 Interface port---0 | 0/0 |
Cisco 7120 series routers | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 3 Interface port---0 | 3/0 |
Cisco 7140 series routers | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 4 Interface port---0 | 4/0 |
Cisco 7200 series routers | Port-adapter-slot-number/interface-port-number | Port adapter slot---0 through 6 (depends on the number of slots in the router)1 Interface port---0 | 1/0 |
Cisco uBR7223 router | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 11 Interface port---0 | 1/0 |
Cisco uBR7246 and Cisco uBR7246 VXR routers | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 1 or 21 Interface port---0 | 1/0 |
VIP2 and VIP4 in Cisco 7000 series or Cisco 7500 series routers | Interface-processor-slot-number/port-adapter-slot- number/interface-port-number | Interface processor slot---0 through 12 (depends on the number of slots in the router) Port adapter slot---always 0 or 1 Interface port---0 | 3/1/0 |
| 1Port adapter slot 0 is reserved for the Fast Ethernet port on the I/O controller (if present). |
This section describes how to identify the interface address used for the PA-A3 on the Catalyst RSM/VIP2 in Catalyst 5000 family switches. The interface address is composed of a two-part number in the format port-adapter-slot number/interface-port number. See Table 1-9 for the interface address format.
This section describes how to identify the interface address used for the PA-A3 in Cisco 7100 series routers. The interface address is composed of a two-part number in the format port-adapter-slot-number/interface-port-number. See Table 1-9 for the interface address format.
This section describes how to identify the interface address used for the PA-A3 in Cisco 7200 series routers or Cisco uBR7200 series routers. The interface address is composed of a two-part number in the format port-adapter-slot-number/interface-port-number. See Table 1-9 for the interface address format.
In Cisco 7200 series routers, port adapter slots are numbered from the lower left to the upper right, beginning with port adapter slot 1 and continuing through port adapter slot 2 for the Cisco 7202, slot 4 for the Cisco 7204 and Cisco 7204VXR, and slot 6 for the Cisco 7206 and Cisco 7206VXR. (Port adapter slot 0 is reserved for the optional Fast Ethernet port on the I/O controller---if present.)
The interface address of the interface on the PA-A3 in port adapter slot 1 is 1/0 (port adapter slot 1 and interface 0). If the PA-A3 was in port adapter slot 4, this same interface would be numbered 4/0 (port adapter slot 4 and interface 0).
In Cisco uBR7200 series routers, the port adapter slots are numbered slot 1 and slot 2 for the Cisco uBR7246 and Cisco uBR7246 VXR and slot 1 for the Cisco uBR7223. (Slot 0 is always reserved for the Fast Ethernet port on the I/O controller---if present.) The individual interfaces always begin with 0.
The interface address of the interface on a PA-A3 in port adapter slot 2 is 2/0 (port adapter slot 2 and interface 0). If the PA-A3 was in port adapter slot 1, this same interface would be numbered 1/0 (port adapter slot 1 and interface 0).
This section describes how to identify the interface address used for the PA-A3 on a VIP2 or VIP4 in Cisco 7000 series and Cisco 7500 series routers.
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Note Although the processor slots in the 7-slot Cisco 7000 and Cisco 7507 and 13-slot Cisco 7513 and Cisco 7576 are vertically oriented and those in the 5-slot Cisco 7010 and Cisco 7505 are horizontally oriented, all Cisco 7000 series and Cisco 7500 series routers use the same method for slot and port numbering. |
See Table 1-9 for the interface address format. The interface address is composed of a three-part number in the format interface-processor-slot number/port-adapter-slot-number/interface-port-number.
The interface address of the interface on a PA-A3 installed in port adapter slot 1 on a VIP2 or VIP4 in interface processor slot 3 of a Cisco 7000 series or Cisco 7500 series router is 3/1/0 (interface processor slot 3, port adapter slot 1, and interface 0). If the port adapter was in port adapter slot 0 on the VIP2 or VIP4, this same interface address would be numbered 3/0/0.
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Note If you remove the VIP2 or VIP4 with the PA-A3 from interface processor slot 3 and install it in interface processor slot 2, the interface address becomes 2/1/0. |
Posted: Fri May 26 10:31:29 PDT 2000
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