RPM-XF Installation and Configuration Guide, Release 3

Installing and Configuring the MGX-1OC12POS-IR Back Card

This chapter describes how to install and configure the single-port OC-12 Packet Over SONET (POS) back card on a Cisco RPM-XF. This chapter includes the following sections:

•Overview and Features

•Installation Guidelines

•Software Configuration

•Troubleshooting the Installation

Overview and Features

The MGX-1OC12POS-IR back card (Figure 5-1) is fully compatible with standards-based POS implementations on platforms such as the Cisco 7200, the Cisco 7500, the Cisco 10000 edge services router (ESR), and the Cisco 12000 series gigabit switch router (GSR).

Figure 5-1 MGX-1OC12POS-IR Back Card

The MGX-1OC12POS-IR back card (see Figure 5-1) provides a trunk uplink that supports OC-12c/STM-4c bandwidth of 622 Mbps throughput over a standard SONET/SDH interface using a single-mode fiber, intermediate-reach SC connector (see Table 5-1).

The MGX-1OC12POS-IR back card provides the following key features:

•Efficient, high-performance bandwidth utilization—OC-12 performance of 622 Mbps provides the bandwidth required to meet the most demanding user requirements, such as faster access to web pages, real-time video, large file transfers, and other data-intensive applications.

The Cisco POS implementation offers a 25 to 30 percent gain in efficiency over multiservice IP traffic now running over ATM networks. It achieves this efficiency gain by eliminating the overhead required in ATM implementations, such as ATM cell header, IP over ATM encapsulation, and segmentation and reassembly (SAR).

•Optimized for IP-based differentiated services—The Cisco POS solution supports Internet-based multiservice networks based on IP. The Cisco POS implementation places the IP layer directly above the SONET layer and eliminates the overhead required to run IP over ATM over SONET.

•Configurable clock sources—The MGX-1OC12POS-IR back card is capable of providing the clock source for the POS link and also retrieving the clock source from network.

•Configurable loopbacks for troubleshooting—The MGX-1OC12POS-IR back card is capable of configuring both an internal loopback (loops outbound traffic back towards the front card) and a network loopback (loops inbound traffic back towards the network).

•Alarm processing—The MGX-1OC12POS-IR back card implements SONET alarms that are fully Bellcore GR-253 compliant.

Installation Guidelines

This section contains guidelines for the following procedures:

•New installation

•Replacement installation

The Cisco MGX-1OC12POS-IR back cards are cold swappable, which means that you can remove and replace the back cards when all interfaces on the back cards are in the shutdown state.

Caution To prevent electrostatic discharge (ESD) damage, handle back cards by the faceplate or the card carrier edges only. Avoid touching the back card printed circuit board, components, or any connector pins.

New Installation Guidelines

For information on installing the back card hardware, see "Installing the MGX RPM-XF Front and Back Cards."

After installing the MGX-1OC12POS-IR back card hardware for the first time, you must configure it by entering the configure command. For information about configuring the MGX-1OC12POS-IR back card, see the "Software Configuration" section below.

Replacement Installation Guidelines

For information on removing and installing the back card hardware, see "Installing the MGX RPM-XF Front and Back Cards."

If an MGX-1OC12POS-IR back card is replaced, the system automatically downloads the necessary information from the RPM-XF front card. There is no need to configure the new back card, unless the front card has been reloaded or switched over subsequent to the removal of the back card of the same type. After the information is downloaded, the system recognizes only those interfaces that match the previous MGX-1OC12POS-IRS back card configuration (those configured as Up).

Software Configuration

After the MGX-1OC12POS-IR back card is successfully installed, you can configure the card for network use.

Note You do not need to configure the MGX-1OC12POS-IR back card if this is a replacement installation. The system automatically downloads the necessary configuration information from the RPM-XF front card.

This section covers the following topics:

•MGX-1OC12POS-IR Back Card Default Values

•MGX-1OC12POS-IR Back Card Syntax

•Configuring the Interface

•Other Configuration Commands

•Example Configuration

•Using show Commands to Check System Status

MGX-1OC12POS-IR Back Card Default Values

Table 5-2 lists default values for the MGX-1OC12POS-IR back card. The commands marked with an asterisk (*) are described in the Cisco IOS command reference documentation. The other commands are among those described in this chapter.

The table includes the command used for modifying a default value and indicates whether a value needs to be the same (or opposite) on the remote end of the connection.

bandwidth kilobits

clock source [line | internal]

crc [16 | 32]

encapsulation [hdlc | ppp]

[no] keepalive period

mtu size

pos framing [sonet | sdh]

[no] pos scramble-atm 

pos flag [c2 | j0 | s1s0] value

MGX-1OC12POS-IR Back Card Syntax

To specify an interface number in a configuration command, use the syntax in Table 5-3 to identify interfaces on the MGX-1OC12POS-IR back card.

The following example shows the syntax for configuring an MGX-1OC12POS-IR back card.

Router(config)# interface pos 1/0

Configuring the Interface

After you verify that the MGX-1OC12POS-IR back card is installed correctly, use the following procedure to configure the new interface. Be prepared with the information you will need, such as the interface IP address.

The following procedure is for creating a basic configuration—Enabling an interface.

Step 1 At the global configuration prompt, specify the new interface to configure by entering the interface pos <bay/port> command and interface address. For example,

Router(config)# interface pos 1/0

Step 2 Assign an IP address and a subnet mask to the interface with the ip address configuration subcommand, as in the following example.

Router(config-if)# ip address 192.168.255.255 255.255.255.0

Step 3 Specify either HDLC or PPP encapsulation. For example,

Router(config-if)# encapsulation hdlc

Step 4 If necessary, modify the MGX-1OC12POS-IR back card configuration or that of the remote device to ensure that, where appropriate, they use the same settings. For more information, see the "Remote Side Setting" column in Table 5-2.

Step 5 Add any other configuration subcommands required for the enabling of routing protocols and adjust the interface characteristics.

Step 6 Enter the no shutdown command to enable the interface.

Router(config-if)# no shutdown

Step 7 When you have included all of the configuration subcommands to complete the configuration, press Cntl-Z to exit configuration mode.

Step 8 Write the new configuration to memory.

Router# copy running-config startup-config

The system displays an OK message when the configuration is stored.

After you complete your configuration, check it by entering the show interface pos <bay/port> command.

Other Configuration Commands

The following sections present some of the commands that you can use to customize your MGX-1OC12POS-IR back card configuration.

This section covers the following topics:

•Setting the Clock Source

•Configuring Framing

•Specifying SONET Overhead

•Configuring POS SPE Scrambling

•Configuring Loopback Testing

Setting the Clock Source

At the prompt, set the internal or line clock source by entering the clock source command.

clock source [internal | line]

The default is clock source line.

In this example, the back card is instructed to use a line clock source.

Router(config)# interface pos 1/0

Router(config-if)# clock source line

Configuring Framing

You can use the pos framing command to set framing to SONET STS-3c or SDH STM-1 framing.

pos framing [sdh | sonet]

[no] pos framing

The default is SONET.

Make sure your system supports SDH before using this option.

Use the no form of the command to restore the default framing mode.

In the following example, the framing type is set to SONET.

Router(config)# interface pos 1/0

Router(config-if)# no pos framing 

Specifying SONET Overhead

You can use the pos flag command to assign values for specific elements of the frame header. This command is typically used to meet a standards requirement or to ensure interoperability with another vendor's equipment.

pos flag [ c2 | j0 | s1s0 value]

[no] pos flag [ c2 | j0 | s1s0 value]

The default values are c2-0xCF, j0-0x01, and s1s0-0.

Use the no form of the command to restore the default values.

In the following example, the c2 bit is set to 0xCF.

Router(config)# interface pos 1/0

Router(config-if)# pos flag c2 0xCF

Configuring POS SPE Scrambling

The pos scramble-atm command allows you to scramble the POS synchronous payload envelope (SPE). SONET payload scrambling applies a self-synchronous scrambler to the SPE of the interface to ensure sufficient bit transition density.

pos scramble-atm

[no] pos scramble-atm

The default is no POS SPE scrambling.

Use the no form of the command to disable scrambling.

In the following example, scrambling is enabled:

Router(config)# interface pos 1/0

Router(config-if)# pos scramble-atm

Configuring Loopback Testing

To enable loopback testing of data transmitted from the front card to the MGX-1OC12POS-IR back card and back, use the loopback command in interface configuration mode.

loopback [line | internal]

[no] loopback [line | internal]

Use the no form of the command to stop the loopback test.

In the following example, a loopback is set for the MGX-1OC12POS-IR back card:

Router(config)# interface pos 1/0

Router(config-if)# loopback line

Example Configuration

The following is an example of configuration file commands for a Cisco RPM-XF with an MGX-1OC12POS-IR back card (Router 1) connected back-to-back with a Cisco 12000 series router with an OC-12c/STM-4c Layer 3 POS back card in slot 3 (Router 2).

Router 1:

interface pos 1/0

ip address 10.1.2.4 255.0.0.0

clock source line

no shutdown

no keepalive

no cdp enable

crc 32

Router 2:

interface pos 3/0

ip address 10.1.2.3 255.0.0.0

clock source internal

no shutdown

no keepalive

no cdp enable

no ip mroute-cache

crc 32

Using show Commands to Check System Status

Each back card maintains information about its configuration, traffic, errors and so on. You can access this information by entering the show commands. Following are descriptions and examples of show commands that display back card information and status.

Enter the show interface pos <bay/port> command to show general information about the interface, as shown in the following example.

Router# show interface pos 1/0

POS1/0 is up, line protocol is up 

  Hardware is Skystone 4302 Sonet Framer

  Internet address is 1.1.100.2/24

  MTU 4470 bytes, BW 622000 Kbit, DLY 100 usec, 

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation HDLC, crc 32, loopback not set

  Keepalive set (10 sec)

  Scramble disabled

  Last input 00:00:02, output 00:00:07, output hang never

  Last clearing of "show interface" counters 00:00:16

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

  Queueing strategy: fifo

  Output queue :0/40 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     0 packets input, 0 bytes, 0 no buffer

     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

     0 packets output, 0 bytes, 0 underruns

     0 output errors, 0 collisions, 0 interface resets

     0 output buffer failures, 0 output buffers swapped out

     0 carrier transitions

Use the show controller pos <bay/port > command to show controller-specific information about the interface, as shown in the following example. For the MGX-1OC12POS-IR back card, this includes information such as, which SONET alarms are currently active, the SONET information received from the remote end, and the SONET configuration parameters.

Router# show controller pos 1/0

POS1/0

SECTION

  LOF = 0          LOS = 0                            BIP(B1) = 0

LINE

  AIS = 0          RDI = 0          FEBE = 0          BIP(B2) = 0

PATH

  AIS = 0          RDI = 0          FEBE = 0          BIP(B3) = 0

  LOP = 0          NEWPTR = 0          PSE = 0           NSE = 0

Active Defects: None

Active Alarms:  None

Alarm reporting enabled for: SF SD SLOS SLOF B1-TCA LAIS LRDI B2-TCA PAIS PLOP PRDI PUNEQ 
B3-TCA 

Framing: SONET

OVERHEAD BYTES

  S1/S0 = 0, C2 = CF

CLOCK RECOVERY

  RDOOL = 0         

  State: RDOOL_state = False

PATH TRACE BUFFER: STABLE

  Remote hostname : Router

  Remote interface: POS1/0

  Remote IP addr  : 0.0.0.0

  Remote Rx(K1/K2): B1/32  Tx(K1/K2): 08/00

BER thresholds:  SF = 10e-3  SD = 10e-6

TCA thresholds:  B1 = 10e-6  B2 = 10e-6  B3 = 10e-6

  Clock source:  internal

Troubleshooting the Installation

Refer to Table 5-4 for descriptions of the LEDs on the MGX-1OC12POS-IR back card. Follow the instructions in Table 5-5 to troubleshoot the installation.