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OC-12c Dynamic Packet Transport Port Adapter for the 7200 Router

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OC-12c Dynamic Packet Transport Port Adapter for the 7200 Router

Table Of Contents

OC-12c Dynamic Packet Transport Port Adapter for the 7200 Router

Feature Overview

Related Documents

Supported Platforms

Supported Standards, MIBs, and RFCs

Prerequisites

Configuration Tasks

Configuring the Dynamic Packet Transport Interface

Verifying DPT

Configuring Intelligent Protection Switching

Verifying Intelligent Protection Switching

Configuring DPT Topology

Verifying DPT Topology

Configuration Examples

DPT Port Adapter

IPS

DPT Topology

Command Reference

srp buffer-size

srp deficit-round-robin

srp loopback

srp priority-map

srp random-detect

srp shutdown

srp tx-traffic-rate

Glossary


OC-12c Dynamic Packet Transport Port Adapter for the 7200 Router


This feature module describes the OC-12c Dynamic Packet Transport Port Adapter (DPT) feature.

This document includes the following sections:

Feature Overview

Supported Platforms

Supported Standards, MIBs, and RFCs

Prerequisites

Configuration Tasks

Configuration Examples

Command Reference

Glossary

Feature Overview

The dual-width OC-12c Dynamic Packet Transport (DPT) port adapter is available on Cisco 7200 series routers and Cisco 7200 VXR series routers. The DPT is an OC-12c interface used in Cisco 7200 series and Cisco 7200 VXR routers to provide a shared IP over SONET capability.

The following benefits are offered by the DPT for the Cisco 7200 and Cisco 7200 VXR series routers:

Accommodates large-scale network topology

Applicable IEEE 802.3 standards

Supports Intelligent Protection Switching (IPS)

Related Documents

For related information on this feature, refer to the following document:

OC-12c Dynamic Packet Transport (DPT) Port Adapter Installation and Configuration

Supported Platforms

Cisco 7200 series routers

Cisco 7200 VXR series routers

Supported Standards, MIBs, and RFCs

MIBs

No new or modified MIBs are supported by this feature.

RFCs

No new or modified RFCs are supported by this feature.

Standards

No new or modified standards are supported by this feature.

Prerequisites

The DPT is compatible with any Cisco 7200 series router equipped with the correct Route Switch Processor (RSP2 or RSP4), running Cisco IOS Release 12.0(6)S or later.

Configuration Tasks

See the following sections for configuration tasks for the DPT interface. Each task in the list indicates if the task is optional or required.

Configuring the Dynamic Packet Transport Interface (Required)

Configuring Intelligent Protection Switching

Configuring DPT Topology

For information on other configuration tasks for the DPT port adapter, refer to the "Configure an Ethernet" section in the "Configuring Interfaces" chapter of the Configuration Fundamentals Configuration Guide.

For information on other commands that can be used by the DP interface, refer to the Cisco IOS Release 12.0 configuration guides.

Configuring the Dynamic Packet Transport Interface

 
Command
Purpose

Step 1 

Router# show running-config

Confirms that the system recognizes the DPT.

Step 2 

Router# configure terminal

Enables configuration mode.

Step 3 

Router(config)# ip routing

Enables IP routing.

Step 4 

Router(config)# interface srp slot/port

Specify interface.

The interface type of the DPT is SRP1 .

Step 5 

Router(config-if)# ip address 192.168.2.3 255.255.255.0

Assign an IP address and subnet mask to the interface.

Step 6 

Add any additional configuration subcommands required to enable routing protocols, and set the interface characteristics for your configuration requirements.

 

Step 7 

Router(config)# no shutdown

Changes the shutdown state to up and enables the interface.

Step 8 

Ctrl-Z

When you have included all the configuration subcommands to complete the configuration, press Ctrl-Z to exit configuration mode.

Step 9 

Router# copy running-config startup-config

Writes the new configuration to the start up configuration.

1 SRP= Spatial Reuse Protocol


The system displays an OK message when the configuration has been stored.

Verifying DPT


Step 1 Use the show running-config command to display the currently running configuration. The example below shows that the current software version is 12.0(8)S, a DPT is installed (the DPT is shown as interface SRP1/0), and the IP address of the DPT:

Router# show running-config 
Building configuration...
Current configuration:
version 12.0(8)S
service timestamps debug uptime
service timestamps log datetime
no service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname uut2
!
interface SRP1/0
 mac-address 0010.5555.6666
 ip address 192.168.0.20 255.255.255.0
 no ip directed-broadcast
ip route-cache distributed

Step 2 Use the show version command to display the configuration of the system hardware and Cisco IOS software information. The following example shows that the Cisco IOS version is 12.0(8)S and a DPT is installed:

router#show version
Cisco Internetwork Operating System Software 
IOS (tm) RSP Software (RSP-JSV-M), Version 12.0(8)S, EARLY DEPLOYMENT RELEASE SOFTWARE 
(fc1)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Sat 18-Dec-99 00:28 by htseng
Image text-base:0x60010908, data-base:0x610B2000

ROM:System Bootstrap, Version 11.1(2) [nitin 2], RELEASE SOFTWARE (fc1)
BOOTFLASH:GS Software (RSP-BOOT-M), Version 11.1(8)CA1, EARLY DEPLOYMENT RELEASE SOFTWARE 
(fc1) 

manta uptime is 8 minutes
System returned to ROM by reload
System image file is "tftp://223.255.254.254/muck/shirjosh/rsp-jsv-mz.120-8.S"

cisco RSP2 (R4700) processor with 131072K/2072K bytes of memory.
R4700 CPU at 100Mhz, Implementation 33, Rev 1.0
Last reset from power-on
G.703/E1 software, Version 1.0.
G.703/JT2 software, Version 1.0.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
Bridging software.
TN3270 Emulation software.
Chassis Interface.
1 EIP controller (2 Ethernet).
2 VIP2 controllers (2 FastEthernet)(1 POS).
1 FEIP controller (2 FastEthernet).
2 Ethernet/IEEE 802.3 interface(s)
4 FastEthernet/IEEE 802.3 interface(s)
1 Packet over SONET network interface(s)
123K bytes of non-volatile configuration memory.

20480K bytes of Flash PCMCIA card at slot 0 (Sector size 128K).
8192K bytes of Flash internal SIMM (Sector size 256K).
No slave installed in slot 3.
Configuration register is 0x0

Configuring Intelligent Protection Switching

The SRP interface uses ring architecture to provide redundancy and protection from a failed node or fiber cut through the use of Intelligent Protection Switching (IPS). The tasks described in this section are optional.

 
Command
Purpose

Step 1 

Router# configure terminal

Enables configuration mode.

Step 2 

Router(config)# interface srp slot/port

Configure an SRP interface.

Step 3 

Router(config-if)# srp ips request manual-switch a

Specifies an IPS manual switch on side A or side B.

Step 4 

Router(config-if)# srp ips wtr-timer 10

Specifies a wait-to-restore request (in seconds) to prevent switch oscillations on side A.

Step 5 

Router(config-if)# srp ips timer 20 a

Configures a message timer to be sent to the inner and outer rings to control the frequency of IPS message transmissions on side A.

Step 6 

Router(config-if)# ^Z

Exits back to EXEC mode so you can perform verification steps.


Verifying Intelligent Protection Switching

Use the show srp command to determine whether an intelligent protection switch is enabled or idle:

router#show srp ips srp1/0

IPS Information for Interface SRP1/0
MAC Addresses
   Side A (Outer ring RX) neighbor 0000.0000.0002
   Side B (Inner ring RX) neighbor 0000.0000.0001
   Node MAC address 0000.0000.0004
IPS State
   Side A not wrapped
   Side B not wrapped
   Side A (Inner ring TX) IPS pkt. sent every 1 sec. (next pkt. after 0 sec.)
   Side B (Outer ring TX) IPS pkt. sent every 1 sec. (next pkt. after 0 sec.)
   IPS WTR period is 60 sec. (timer is inactive)
   Node IPS State IDLE
IPS Self Detected Requests     IPS Remote Requests
   Side A IDLE                    Side A IDLE
   Side B IDLE                    Side B IDLE
IPS messages received
   Side A (Outer ring RX) {0000.0000.0002,IDLE,S}, TTL 128   age 00:00:04
   Side B (Inner ring RX) {0000.0000.0001,IDLE,S}, TTL 128   age 00:00:00
IPS messages transmitted
   Side A (Inner ring TX) {0000.0000.0004,IDLE,S}, TTL 128
   Side B (Outer ring TX) {0000.0000.0004,IDLE,S}, TTL 128

Configuring DPT Topology

Every node on a DPT ring maintains a topology map of the ring, so that it knows where to route traffic. It updates the topology map by periodically sending a query, called a topology discovery packet, out onto the outer-ring path. Each node on the ring adds its own MAC address to the packet. When the discovery packet returns to the originating node, the contents of the packet are used to update the topology map. You use the srp topology-timer command to set the frequency with which the node sends out topology discovery packets.

 
Command
Purpose

Step 1 

Router# configure terminal

Enables configuration mode.

Step 2 

Router(config)# interface srp slot/port

Configure an SRP interface.

Step 3 

router(config-if)# srp topology-timer 70

Configures the frequency of the topology message timer in seconds.

Step 4 

router(config-if)# ^Z

Exits back to EXEC mode so you can perform verification steps.

Step 5 

router# show srp topology

Confirm the identity of the nodes on the ring by entering the show srp topology command. The command output also shows the number of hops between nodes and identifies the nodes that are in wrap mode.


Verifying DPT Topology

Use the show srp topology command to show the identity of the nodes on the DPT ring according to their MAC addresses. The following example shows a three-node DPT ring.

router#show srp topology

Topology Map for Interface SRP2/0
  Topology pkt. sent every 5 sec. (next pkt. after 4 sec.)
  Last received topology pkt. 00:00:00
  Nodes on the ring:4
  Hops (outer ring)      MAC       IP Address      Wrapped Name
      0             0000.0000.0004 2.2.2.4           No    stingray
      1             0000.0000.0001 2.2.2.1           No    npe300
      2             0000.0000.0005 2.2.2.5           No    gsr
      3             0000.0000.0002 2.2.2.2           No    tuna

Configuration Examples

This section provides the following configuration examples:

DPT Port Adapter

IPS

DPT Topology

DPT Port Adapter

In the following example, the OC-12c DPT SRP interface is specified and the IP address and subnet mask is assigned to the interface.

Router(config)# interface srp 0/1
Router(config-if)# ip address 192.168.2.3 255.255.255.0 

IPS

In the following example the SRP IPS options are configured:

Router(config)# interface srp slot/port
srp ips request manual-switch a
srp ips wtr-timer 60
srp ips timer 90 

DPT Topology

In the following example, the identity of the nodes on the DPT ring according to their MAC addresses is shown. The following example shows a three-node DPT ring. Nodes 0 and 2 are wrapped:

router# show srp topology

Topology Map for Interface SRP2/0
  Topology pkt. sent every 5 sec. (next pkt. after 4 sec.)
  Last received topology pkt. 00:00:00
  Nodes on the ring:4
  Hops (outer ring)      MAC       IP Address      Wrapped Name
      0             0000.0000.0004 2.2.2.4           No    stingray
      1             0000.0000.0001 2.2.2.1           No    npe300
      2             0000.0000.0005 2.2.2.5           No    gsr
      3             0000.0000.0002 2.2.2.2           No    tuna

Command Reference

This section documents new commands. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications.

srp buffer-size

srp deficit-round-robin

srp loopback

srp priority-map

srp random-detect

srp shutdown

srp tx-traffic-rate

The SRP interface provides commands to enforce quality of service (QoS) functionality on the transmit side and receive side of Cisco routers. SRP uses the IP type of service (ToS) field values to determine packet priority.

On the transmit side the SRP interface classifies traffic into high- and low- priority traffic. High- priority traffic is rate shaped and has higher priority than low-priority traffic. The user has the option to configure high- or low-priority traffic and can rate limit the high-priority traffic.

srp buffer-size

To make adjustments to buffer settings on the receive side for different priority traffic, use the srp buffer-size interface configuration command. Use the no form of this command to disable buffer size configurations.

srp buffer-size receive [high | medium]

no srp buffer-size receive [high | medium]

Syntax Description

receive

Allocates synchronous dynamic random-access memory (SDRAM) buffer for incoming packets.

high | medium

Buffer size for high- or medium-priority packets. Any number from 16 to 8192 in bytes.


Defaults

high = 4096 kbytes, medium = 4096 kbytes, low = 8192 kbytes

Command Modes

Interface configuration mode

Command History

Release
Modification

12.0(6)S

This command was introduced.


Examples

The following example shows the buffer size for the receive side at the high setting of 17 kbytes:

router(config-if)# srp buffer-size receive high 17

Related Commands

Command
Description

mtu bytes

Adjusts the maximum packet size MTU size.1

srp deficit-round-robin

Sets SRP parameters.

1 MTU = maximum transmission unit


srp deficit-round-robin

To transfer packets from the internal receive buffer to IOS, use the srp deficit-round-robin configuration command. Use the no form of this command to disable srp deficit-round-robin.

srp deficit-round-robin [input | output] [quantum | deficit]

no srp deficit-round-robin

Syntax Description

input | output

Either input or output is specified.

high | medium | low

Priority queue level.

quantum

DRR quantum value. Any number from 9216 to 32767. The default is 9216.

deficit

DRR deficit value. Any number from 0 to 65535. The default is 16384.


Defaults

quantum = 9216, deficit = 16384

Command Modes

Configuration mode

Command History

Release
Modification

12.0(6)S

This command was first introduced.


Examples

The following example shows packets configured for the high-priority input queue:

Router(config-if)# srp deficit-round-robin input high deficit 

Related Commands

Command
Description

srp priority-map receive

Enables classification of packets as high, medium, or low based on the IP TOS value

srp buffer-size

Modifies the buffer space allocated for different priority traffic. By default high- and medium-priority packets get 4 MB of buffer space, and low-priority packets get 8 MB of buffer space.

srp random-detect

Enables user to tune WRED parameters on packets received through the SRP interface.


srp loopback

To loop the SRP interface on a OC-12c DPT, use the srp loopback interface configuration command. Use the no form of this command to remove the loopback.

srp loopback {internal | line} {a | b}

no srp loopback

Syntax Description

internal | line

Sets the loopback toward the network before going through the framer (internal), or loops the payload data toward the network (line).

a

Loopback the A side of the interface (inner tx, outer rx)

b

Loopback the B side of the interface (outer tx, inner rx).


Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

12.0(6)S

This command was modified.


Usage Guidelines

Use this command for troubleshooting purposes.

Examples

The following example configures the loopback test on the a side of the SRP interface:

srp loopback line a 

srp priority-map

To set priority mapping for transmitting and receiving packets, use the srp priority-map configuration command. Use the no form of this command to disable priority mapping.

srp priority-map {receive} {high | medium | low}{transmit}{high | medium}

no srp priority-map

Syntax Description

receive | transmit

Receiving or transmitting.

high | medium

Mapping for high- or medium-priority packets. Range is between 1 and 8.

low

Specifies mapping for low-priority packets on the receive side.


Defaults

receive high = 5, receive medium = 3, transmit = 7

Command Modes

Configuration mode

Command History

Release
Modification

12.0(6)S

This command was introduced.


Usage Guidelines

The SRP interface provides commands to enforce quality of service (QoS) functionality on the transmit side and receive side of Cisco routers. SRP uses the IP type of service (ToS) field values to determine packet priority.

The SRP interface classifies traffic on the transmit side into high- and low-priority traffic. High-priority traffic is rate shaped and has higher priority than low-priority traffic. You have the option to configure high- or low-priority traffic and can rate limit the high-priority traffic.

The command srp priority-map transmit enables the user to specify IP packets with <tos-value> and above to be considered as high-priority traffic.

On the receive side, when WRED is enabled, SRP hardware classifies packets into high-, medium-, and low-priority packets based on IP ToS value. After classification, it stores the packet into the internal receive buffer. The receive buffer is partitioned for each priority packet. Cisco routers can employ WRED based on the IP ToS value. Routers also employ the Deficit Round Robin (DRR) algorithm to transfer packets from the internal receive buffer to IOS.

The command srp priority-map receive enables the user to classify packets as high, medium, or low based on the IP ToS value.

Examples

The following example configures the Cisco 7200 series routers to transmit packets with priority greater than 5 as high priority packs:

Router(config-if)# srp priority-map transmit 5

Related Commands

Command
Description

random detect

Configures WRED parameters on packets received through an SRP interface.


srp random-detect

To configure WRED parameters on packets received through an SRP interface, use the srp random-detect interface configuration command. Use the no form of this command to return the value to the default.

srp random-detect [enable | compute-interval | input | precedence]

no srp random-detect

Syntax Description

compute-interval

Interval in the range of 1 to 128 nsec used to specify the queue depth compute interval.

enable

Enable WRED

input

WRED on packet input path.

high | low | medium

Priority queue level.

exponential-weight

Queue weight in bits. Any number from 0 to 6.

precedence

Input queue precedence.


Defaults

128 seconds

Command Modes

Interface configuration command

Command History

Release
Modification

12.0(6)S

This command was introduced.


Examples

The following example has configured WRED parameters on packets received through an SRP interface with a weight factor of 5:

Router(config-if)# srp random-detect input high exponential-weight 5 

srp shutdown

To disable the SRP interface, use the shutdown interface configuration command. To restart a disabled interface, use the no form of this command.

srp shutdown [a | b]

no srp shutdown [a | b]

Syntax Description

a

Specifies side A of the SRP interface.

b

Specifies side B of the SRP interface.


Defaults

Not enabled

Command Modes

Interface configuration

Command History

Release
Modification

12.0(6)S

This command was introduced.


Usage Guidelines

The srp shutdown command disables all functions on the specified interface.

Examples

The following example turns off the A side of the SRP interface:

srp shutdown a

srp tx-traffic-rate

To limit the amount of high-priority traffic that the SRP interface can handle, use the srp tx-traffic-rate configuration command. Use the no form of this command to disable transmitted traffic rate.

srp tx-traffic number

no srp tx-traffic number

Symptom    Syntax Description

number

The range in kilobits. The range is 1 to 65535.


Defaults

10 Mbps

Command Modes

Configuration mode

Command History

Release
Modification

12.0(6)S

This command was introduced.


Examples

The following example shows SRP transmitted traffic transmitting at 1000 kilobits per second:

Router(config-if)# srp tx-traffic-rate 1000

Glossary

DPT—Dynamic Packet Transport.

DRR—Deficit Round Robin.

IPS—Intelligent Protection Switching.

MAC—Media Access Control.

MTU—Maximum Transmission Unit.

QoS—Quality of Service.

RSP—Route Switch Processor.

SDRAM—Synchronous Dynamic Random-access Memory.

SONET—Synchronous Optical Network. An American National Standards Institute (ANSI) standard (T1.1051988) for optical digital transmission at hierarchical rates from 51.840 Mbps (OC-1) to 2.488 Gbps (OC-48) and higher.

SRP—Spatial Reuse Protocol. A Layer 2 MAC protocol for use with DPT, SONET, and SDH rings that runs over a dual-ring network topology and is characterized by shared media, statistical multiplexing, global fairness, and spatial reuse.

ToS—Type of Service.

WRED—Weighted Random Early Detection.