|
|
This chapter describes the PA-4E1G port adapter and contains the following sections:
The PA-4E1G, shown in Figure 1-1 and Figure 1-2, provide up to four E1 synchronous serial interfaces, which are compatible with and specified by G.703/G.704. The PA-4E1G network interfaces provide a connection between standard serial interfaces such as V.35 to telephone lines or Post, Telephone, and Telegraph (PTT) networks. Each PA-4E1G interface operates in full-duplex mode at E1 (2.046-Mbps) speed.
The PA-4E1G interfaces do not operate in the data terminal equipment (DTE) and data communications equipment (DCE) modes that are typical of data communications interfaces. The PA-4E1G interfaces operate with either a line-recovered or an internal clock signal. The default is for a line clock signal that the interface recovers from the received data stream. The interface can also operate with an internal clock signal. The PA-4E1G generates the internal clock signal; the interface does not use the motherboard or system clock.
The PA-4E1G provides the following features and capabilities:
 |
Note PA-4E1Gs are available as spare parts (PA-4E1G-120[=] and PA-4E1G-75[=]). |
Each PA-4E1G interface is available in either balanced (120-ohm) or unbalanced (75-ohm) mode; a unique port adapter supports each type. Neither the balanced and unbalanced modes nor the balanced and unbalanced cables are interchangeable; you cannot configure a balanced port to support an unbalanced line, nor can you attach an interface cable intended for a balanced line to an unbalanced port.
Balanced interfaces typically use three conductors and three signal states: high, low, and ground. The high and low signals mirror each other. Unbalanced interfaces use only two signals: signal and ground. You can discover the mode of each interface by examining the agency approval label on each port adapter, or by using the show controller cbus command.
Following is an example of discovering whether the PA-4E1G is in balanced or unbalanced mode:
Router# show controllers cbus Serial1/1/0, applique is G.703 Unbalanced [remainder of displayed text omitted from example] Serial1/1/1, applique is G.703 Unbalanced [remainder of displayed text omitted from example]
The PA-4E1G interface is divided into 32 time slots or frames. (See Figure 1-3.)
Each of the 32 time slots is an 8-bit frame that transmits data at 64 kbps. Each of these time slots can be configured to carry data or to remain empty. (The PA-4E1G inserts an idle pattern into empty time slots.)
Time slot 0, or the first 8 bits, is reserved as overhead. The remaining 248 bits (31 frames with 8 bits each) are designated time slots 1 through 31. Time slot 16 is also designated as a framing slot when using framed mode. When you use framed mode (G.704), you can configure time slot 16 to carry data and operate as any of the other slots; therefore, in framed mode time slot 0 must be designated as a framing signal; time slot 16 can be configured for either data or framing.
With framed mode (G.704) you can specify a bandwidth for the interface by designating 31 of the time slots for data and reserving time slot 0 for framing (timing). When you use framed mode, you must designate start and stop time slots; the slots within the start and stop boundaries are used for data, and the remaining slots are left idle. For example, on an interface with framing set on time slots 1 through 8, the interface carries data within the specified 8 frames, and frames 9 through 31 remain idle. Because each time slot transmits at 64 kbps, the interface operates at 512 kbps (8 frames x 64 kbps = 512 kbps).
By configuring 16 of the time slots to carry data and the other 16 to remain empty, you can essentially configure the interface for 1.024 Mbps (by leaving half the time slots empty and unable to carry data). The system inserts an idle pattern into unused time slots to identify them as overhead (unused for data). Only one contiguous time slot range can be used. In Private Automatic Branch Exchange (PABX) systems, time slot 16 is always left unused. By default, time slot 16 is not enabled for data in the PA-4E1G interface. The command ts16 overrides the default and enables time slot 16 to carry data.
Unframed mode (G.703) uses all 32 time slots for data. None of the 32 time slots are used for framing signals. This allows each of the 32 time slots to transmit at 64 kbps; therefore, 32 time slots x 64 kbps = 2.048 Mbps. While unframed mode is the default, you can also specify unframed mode with the command timeslot 0-0, which specifies time slot 0 as the start slot with no stop (ending) time slot; therefore, all slots are used for data. The no timeslot command restores the default of unframed mode.
Framed mode supports a 4-bit cyclic redundancy check (CRC4), which you enable with a software command. The default is for no CRC.
|
Note The E1-G.703/G.704 interface on PA-4E1G is compliant with BABT 221. |
For more information about CRC4 with PA-4E1G on a VIP2, Cisco 7100 series, Cisco 7200 series routers, or Cisco uBR7200 series routers, refer to "Configuring the PA-4E1G."
The PA-4E1G has one row of three status LEDs for each port, and one enabled LED. (See Figure 1-4.) The green- and amber-colored LED for each port indicates port status.
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-4E1G 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 port LED colors and indications.
| LED Label | Color | State | Meaning |
ENABLED | Green | On | Port adapter is enabled for operation. |
Local alarm (LA) | Amber | On | A loss of signal (LOS), a loss of frame (LOF), an alarm indication signal (AIS), or any combination of these is detected. |
Remote alarm (RA) | Amber | On | A remote source indicates an error on its incoming signal. |
Loopback (LB) | Amber | On | Line or local loopback is active. |
This section describes the port adapter cables for data communications and the PA-4E1G interfaces. Each PA-4E1G provides up to four 15-pin, D-shell (DB-15) receptacles, which support only E1-G.703/G.704 interfaces.
The PA-4E1Gs use a DB-15 receptacle for both the balanced and unbalanced ports. The label on the port adapter indicates if the ports on that port adapter are 75-ohm or 120-ohm. (See Figure 1-1 and Figure 1-2.)
The port adapter end of all E1-G.703/G.704 adapter cables is a DB-15 connector. At the network end, the adapter cable for unbalanced (75-ohm) connections uses a BNC connector. The adapter cables for balanced (120-ohm) connections use DB-15, twinaxial, or RJ-45 connections to accommodate connection standards in different countries.
|
Note You must connect the correct type of interface cable for the port to operate. You must use the proprietary cables to connect the E1-G.703/G.704 port to your network; these cables are shipped from Cisco Systems with your port adapter. |
 |
Warning It is a requirement of the statutory approval of the E1-G.703/G.704 interface that the jackscrews of the connector backshell are securely screwed down while the port adapter is operating. |
Cables for balanced and unbalanced mode are available with the following types of network-end connectors:
Table 1-2 lists the product numbers and descriptions of the E1-G.703/G.704 cables.
| Cable Product Numbers | Description |
|---|---|
CAB-E1-TWINAX=1 | E1 cable, twinaxial, 120-ohm, balanced, 5 m |
CAB-E1-DB15= | E1 cable, DB-15, 120-ohm, balanced, 5 m |
CAB-E1-RJ45= | E1 cable, RJ-45, 120-ohm, balanced, 5 m |
CAB-E1-BNC= | E1 cable, BNC, 75-ohm, unbalanced, 5 m |
| 1The appended equal sign (=) indicates a spare part. |
Unbalanced G.703 interfaces allow for a longer maximum cable length than those specified for balanced circuits. Table 1-3 lists the maximum cable lengths for each E1-G.703/G.704 cable type by the connector used at the network (non-port adapter) end.
| Connection Type | BNC | Twinaxial |
|---|---|---|
Balanced | - | 300 m |
Unbalanced | 600 m | - |
Table 1-4 shows the signal pinouts for each type of E1-G.703/G.704 interface cable. All cables use a DB-15 connector at the port adapter end.
| Port Adapter End | Network End | |||||||
|---|---|---|---|---|---|---|---|---|
| DB-151 | DB-152 | DB-15 (Null Modem) | Twinaxial2 | RJ-452 | BNC3 | |||
| Pin | Signal4 | Pin | Pin | Signal | Pin | Signal | Signal | |
9 | Tx tip | 1 | 3 | Rx tip | 4 | Rx tip | Tip |
|
2 | Tx ring | 9 | 11 | Rx ring | 5 | Rx ring | Shield |
|
10 | Tx shield | 2 | 4 | Rx shield | 6 | Rx shield | - |
|
8 | Rx tip | 3 | 1 | Tx tip | 1 | Tx tip | Tip |
|
15 | Rx ring | 11 | 9 | Tx ring | 2 | Tx ring | Shield |
|
7 | Rx shield | 4 | 2 | Tx shield | 3 | Tx shield | - |
|
| 1Any pins not described in this table are not connected. 2120-ohm, balanced cable. 375-ohm, unbalanced cable. 4Tx = transmit. Rx = receive. |
This section discusses port adapter slot locations on the supported platforms. The illustrations that follow summarize slot location conventions on each platform.
The PA-4E1G 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-4E1G can be installed in any available port adapter slot.)
Figure 1-12 shows the slot numbering of port adapters in a Cisco uBR7246 series router. The port adapter slots are numbered slot 1 and slot 2 for the Cisco uBR7246 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, 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.
|
Note In the Cisco 7000, Cisco 7507, and Cisco 7513 chassis, the VIP motherboard is installed vertically. In the Cisco 7010 and Cisco 7505 chassis, the VIP motherboard is installed horizontally. |
This section describes how to identify interface addresses for the PA-4E1G in supported platforms. Interface addresses specify the actual physical location of each interface on a router or switch.
Interfaces on the PA-4E1G 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-4E1G 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 1-5 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 3 | 3/1 |
Cisco 7140 series routers
| Port-adapter-slot-number/interface-port-number
| Port adapter slot---always 4 Interface port---0 through 3 | 4/1 |
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 3 | 1/0 |
Cisco uBR7223 router | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 11 Interface port---0 through 3 | 1/0 |
Cisco uBR7246 router | Port-adapter-slot-number/interface-port-number | Port adapter slot---always 1 or 21 Interface port---0 through 3 | 1/2 |
VIP2 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 through 3 | 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-4E1G 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 1-5 for the interface address format.
This section describes how to identify the interface addresses used for the PA-4E1G 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 1-5 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 addresses of the interfaces on the PA-4E1G in port adapter slot 1 are 1/0 through 1/3 (port adapter slot 1 and interfaces 0 through 3). If the PA-4E1G was in port adapter slot 4, these same interfaces would be numbered 4/0 through 4/3 (port adapter slot 4 and interfaces 0 through 3).
In Cisco uBR7200 series routers, the port adapter slots are numbered slot 1 and slot 2 for the Cisco uBR7246 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 number of additional interfaces depends on the number of interface ports on a port adapter.
The interface addresses of the interfaces on a PA-4E1G in port adapter slot 2 are 2/0 through 2/3 (port adapter slot 1 and interfaces 0 through 3). If the PA-4E1G was in port adapter slot 1, these same interfaces would be numbered 1/0 through 1/3 (port adapter slot 1 and interfaces 0 through 3).
This section describes how to identify the interface addresses used for the PA-4E1G on a VIP2 in Cisco 7000 series and Cisco 7500 series routers.
|
Note Although the processor slots in the 7-slot Cisco 7000 and Cisco 7507 and the 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 1-5 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.
If the VIP2 is inserted in interface processor slot 3, then the interface addresses of the PA-4E1G are 3/1/0 through 3/1/3 (interface processor slot 3, port adapter slot 1, and interfaces 0 through 3). If the port adapter was in port adapter slot 0 on the VIP2, these same interface addresses would be numbered 3/0/0 through 3/0/3.
|
Note If you remove the VIP2 with the PA-4E1G from interface processor slot 3 and install it in interface processor slot 2, the interface addresses become 2/1/0 through 2/1/3. |
Posted: Tue Feb 15 12:31:30 PST 2000
Copyright 1989 - 2000©Cisco Systems Inc.
