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This chapter describes the PA-A3-IMA port adapter and contains the following sections:
The PA-A3-IMA (see Figure 1-1 and Figure 1-2) is a single-width port adapter that allows Cisco 7100 series, Cisco 7200 series, Cisco 7200 VXR, and Cisco 7500 series routers to support inverse multiplexing over ATM. The PA-A3-IMA supports data rates between DS1 and DS3 levels, or E1 and E3 levels by combining the bandwidth of multiple DS1 or E1 links into groups that collectively provide higher intermediate rates. This Peripheral Component Interconnect (PCI)-based port adapter is available in a T1 version (PA-A3-8T1IMA) and an E1 version (PA-A3-8E1IMA).
The PA-A3-IMA can be installed in any Cisco 7100 series, Cisco 7200 series, or Cisco 7200 VXR router, or on the VIP2 for Cisco 7500 series router. There are no restrictions on slot locations or sequence for the Cisco 7500 series, Cisco 7200 series, or Cisco 7200 VXR routers; you can install a PA-A3-IMA in any available port adapter slot. The PA-A3-IMA has designated slots in the Cisco 7100 series routers. See the "Port Adapter Slot Locations on the Supported Platforms" section for their location.
Inverse multiplexing (IMA) provides a means of access to ATM networks at rates between DS1/E1 and DS3/E3 levels (1.544 Mbps/2.048 Mbps to 44.736 Mbps/34.368 Mbps) by combining the bandwidth of multiple DS1/E1 links into groups that collectively provide higher intermediate rates. This is especially desirable in networks where DS3/E3 links are scarce.
IMA breaks up the ATM cell stream and distributes the cells over the multiple physical links of an IMA group (inverse multiplexing) and then recombines the cells into a single stream at the other end of the connection. The ATM cells are distributed in a round robin fashion over the physical links of the IMA group, demultiplexed at the receiving IMA group, and passed in their original form to the ATM layer (see Figure 1-3). Using the multiple links of an IMA group increases the logical link bandwidth to approximately the sum of the individual link rates.
The PA-A3-IMA has the following features:
The PA-A3-IMA has ten LEDs: one bicolor alarm LED, one green enabled LED, and eight bicolor port status LEDs (see Figure 1-4).
LEDs on the PA-A3-IMA--Horizontal Orientation
After system initialization, the enabled LED goes on to indicate that the port adapter has been enabled for operation.
The following conditions must be met before the PA-A3-IMA is enabled:
If any of the above conditions are not met, or if the initialization fails for other reasons, the enabled LED does not go on.
Table 1-1 lists LED colors and indications.
| LED Label | Color | State | Function |
ALRM | Yellow | On | Indicates a minor alarm on one of the T1/E1 ports |
Red | On | Indicates a major alarm on one of the T1/E1 ports | |
ENABLED | Green | On | Indicates IMA port adapter is enabled for operation |
Port 0-7 | Green | On | Indicates port is enabled and in frame |
Green/Yellow | Off | Indicates port is not initialized or is in alarm condition | |
Yellow | On | Indicates port is in loopback |
The eight DS1/E1 interface receptacles on the PA-A3-IMA are RJ-45 for T1 (100-ohm) or E1 (120-ohm). All eight may be used simultaneously as ATM interfaces, or they may be used to create IMA groups.
Each connection supports T1 (100-ohm) or E1 (120-ohm) interfaces that meet T1.403 and ACCUNET TR62411 standards. The RJ-45 connection does not require an external transceiver. The DS1 ports are T1 interfaces that use foil twisted-pair (FTP) cables.
Figure 1-5 shows the PA-A3-IMA interface cable connector. See "Connecting the PA-A3-IMA Interface Cables," for directions on connecting the cables of an IMA group.
Table 1-2 lists the signal pinouts and descriptions for the RJ-45 connector.
| Pin | Signal | Signal | To |
|---|---|---|---|
J1-1 | RX1 ring | TX2 ring | J2-4 |
J1-2 | RX tip | TX tip | J2-5 |
J1-4 | TX ring | RX ring | J2-1 |
J1-5 | TX tip | RX tip | J2-2 |
J1-3 | RX shield | TX shield | NC |
J1-7 | NC3 | NC |
|
J1-6 | TX shield | RX shield | NC |
J1-8 | NC | NC |
|
| 1RX = receive 2TX = transmit 3NC = no connect |
The following sections provide port adapter slot locations and related information:
The PA-A3-IMA can be installed in port adapter slot 3 in the Cisco 7120 series routers, and in port adapter slot 4 in the Cisco 7140 series routers. Figure 1-6 shows a Cisco 7120 with a port adapter installed in slot 3. Figure 1-7 shows a Cisco 7140 with a port adapter installed in slot 4.
Figure 1-8 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-IMA can be installed in any available port adapter slot.
7206
Figure 1-9 shows a VIP2-15, VIP2-20, or VIP2-40 with installed port adapters. With the VIP2 oriented as shown in Figure 1-9, the left port adapter is in port adapter slot 0, and the right port adapter is in port adapter slot 1. The slots are always numbered 0 and 1.
This section describes how to identify interface addresses for the PA-A3-IMA in supported platforms. Interface addresses specify the actual physical location of each interface on a router or switch.
Interfaces on the PA-A3-IMA installed in a router maintain 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.
Interfaces on a PA-A3-IMA installed in a VIP2 maintain the same address regardless of whether other interface processors are installed or removed. However, when you move a VIP2 to a different slot, the interface processor slot number changes to reflect the new interface processor slot.
Table 1-3 explains how to identify interface addresses.
| Platform | Interface Address Format | Numbers | Syntax |
|---|---|---|---|
Cisco 7120 series routers | Port-adapter-slot-number/interface-port-number | Port adapter slot--always 3 Interface port--0 through 7 | 3/0 |
Cisco 7140 series routers | Port-adapter-slot-number/interface-port-number | Port adapter slot--always 4 Interface port--0 through 7 | 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 through 7 | 1/0 |
VIP2 in Cisco 7500 series routers | Interface-processor-slot-number/port-adapter-slot-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 through 7 | 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 addresses used for the PA-A3-IMA 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 1-3 for the interface address format.
In Cisco 7120 series routers, slot 3 is the port adapter slot you can use for the PA-A3-IMA.
(See Figure 1-6.) On a PA-A3-IMA installed in slot 3, the interface addresses of the eight interfaces are 3/0 through 3/7 (port adapter slot 3 and interfaces 0 through 7).
In Cisco 7140 series, slot 4 is the port adapter slot you can use for the PA-A3-IMA. (See Figure 1-7.) On a PA-A3-IMA installed in slot 4, the interface addresses of the eight interfaces are 4/0 through 4/7 (port adapter slot 4 and interfaces 0 through 7).
This section describes how to identify the interface addresses used for the PA-A3-IMA in Cisco 7200 series series routers. The interface address is composed of a two-part number in the format port-adapter-slot-number/interface-port-number. See Table 1-3 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.) Figure 1-10 shows the interfaces of a PA-A3-IMA port adapter in port adapter slot 3 of the Cisco 7206 router.
--Cisco 7206 Shown
The interface addresses of the interfaces on the PA-A3-IMA in port adapter slot 1 are
1/0 through 1/7 (port adapter slot 1 and interfaces 0 through 7). If the PA-A3-IMA was in port adapter slot 4, these same interfaces would be numbered 4/0 through 4/7 (port adapter slot 4 and interfaces 0 through 7).
This section describes how to identify the interface addresses used for the PA-A3-IMA on a VIP2 in Cisco 7500 series routers.
See Table 1-3 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.
Figure 1-11 shows a sample Cisco 7505 system. The interface addresses of the PA-A3-IMA are 3/0/0 through 3/0/7 (interface processor slot 3, port adapter slot 0, and interfaces 0 through 7). If the port adapter was in port adapter slot 1 on the VIP2, these same interface addresses would be numbered 3/1/0 through 3/1/7.
Posted: Mon Aug 7 17:25:18 PDT 2000
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