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Table Of Contents
How to Configure SCMP Parameters
How to Add an SCMP Peer Device
How to Delete Subscribers Managed by an SCMP Peer Device
How to Delete an SCMP Peer Device
How to Define the Subscriber ID
How to Configure the RADIUS Client
How to Monitor the SCMP Environment
How to Monitor the RADIUS Client
Managing the SCMP
This module provides an overview of the Service Control Management Protocol (SCMP) capabilities. It also explains the various procedures for configuring and monitoring SCMP.
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How to Monitor the SCMP Environment
About SCMP
The Service Control Management Protocol (SCMP) is a protocol that integrates the SCE platform and the ISG (Intelligent Service Gateway) functionality of the Cisco routers, thereby providing a mechanism that allows the ISG and the SCE platform to manage subscriber sessions together without requiring coordination and orchestration by additional components.
The SCMP is a Cisco proprietary protocol that uses the RADIUS protocol with CoA (Change of Authorization) support as a transport layer. The SCMP provides connection management messages, subscriber management and subscriber accounting messages. Each subscriber in the SCE platform represents a session in the SCMP peer (as defined by the ISG terminology).
Connection management
The SCE platform initiates the connection to the peer device. On SCMP connection establishment, the SCE platform and ISG negotiate the following details:
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Subscriber Management
The SCMP peers can work in either of two introduction modes. These introduction modes affect only how and when a session is created on the SCE platform:
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The SCMP uses queries as a backup to the push introduction mode, to be robust to issues such as networking problems and SCE platform reboot.
In addition to session creation, the SCMP supports the following operations:
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Subscriber Accounting
On session creation, the SCE platform sends an accounting start message for the session and on logout, it sends an accounting stop message for the session. In addition, for each SCA BB service-counter an accounting-session is maintained (start, interim and stop messages), which provides information regarding the relevant volume, flow-count and duration.
The accounting messages are based on the new Subscriber-Accounting RDR and are sent according to the interval defined in the PQB configuration.
SCMP Terminology
SCMP terminology is similar to, but not identical to, existing SCE platform terminology. It is derived from the ISG terminology, since every SCE subscriber is actually an ISG session.
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Each session is assigned a unique identifier.
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Deployment Scenarios
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The following sections illustrate the basic types of SCMP deployment scenarios.
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Single ISG Router with a Single SCE Platform (1xISG - 1xSCE)
The following diagram illustrates a deployment using one ISG router with a single SCE platform.
Figure 14-1 Single ISG Router with a Single SCE Platform
Note the following:
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Single ISG Router with Two Cascaded SCE Platforms (1xISG - 2xSCE)
The following diagram illustrates a deployment using one ISG router with two cascaded SCE platforms.
Figure 14-2 Single ISG Router with Two Cascaded SCE Platforms
This scenario is similar to the previous one, with ISG running on a service gateway or BRAS terminating a large number of subscribers, however a second SCE platform has been added to provide redundancy. This redundancy scheme assumes that SCE platforms are connected in a cascade, with one active SCE platform and one backup.
Please note the following:
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Multiple ISG Routers with Two Cascaded SCE Platforms (NxISG - 2xSCE)
The following diagram illustrates a deployment using multiple ISG routers with two cascaded SCE platforms.
Figure 14-3 Multiple ISG Routers with Two Cascaded SCE Platforms
Many SPs require an edge platform with MPLS functionality to support L2 and L3 VPN services for business customers, with the possibility of running subscriber management functions for residential and business subscribers terminating on the same platform. If advanced services requiring deep packet inspection are offered, we recommend locating the SCE platforms centrally, just before traffic requiring such services exits the SP network, since not all traffic needs to be processed by SCE platforms. Please note the following:
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Multiple ISG Routers with Multiple SCE Platforms via Load Balancing (NxISG - MxSCE)
The following diagram illustrates a deployment using multiple ISG routers with multiple SCE platforms via load balancing. This is the scenario required for a MGSCP deployment.
Figure 14-4 Multiple ISG Routers with Multiple SCE Platforms via Load Balancing
This scenario includes several SCE platforms connected to the 7600/6500 switch. For efficient control of subscriber flows, the same SCE platform must process both directions of each subscriber flow, since the SCE platform keeps the subscriber context. The 7600/6500 switch to which the SCE platforms are connected acts as a dispatching element, distributing subscriber flows between SCE platforms and guaranteeing that all flows of a specific subscriber will pass through the same SCE platform.
This scenario assumes that one (or sometimes more) of the devices in the cluster is redundant.
Please note the following:
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SCMP Peer Devices
An SCMP peer device is a Cisco device running IOS with the ISG module enabled. The SCE platform supports the ability to communicate with several SCMP peer devices at the same time. However, each peer device manages its own subscribers and the corresponding subscriber network IDs. The SCE platform recognizes which subscribers belong to which peer device. There are two mechanisms that accomplish this:
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Each SCMP peer device is assigned a unique ID called the Manager-Id. This ID is attached to each subscriber from the moment it is created in the subscriber database, based on the SCMP peer that logged-in the subscriber.
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An anonymous group is a specified IP range, possibly assigned a subscriber template (see Anonymous Groups and Subscriber Templates ).
SCMP associates each SCMP peer device with at least one anonymous group. SCMP generates subscribers for this anonymous group when it detects traffic from the SCMP peer device that is not mapped to any subscriber. SCMP assigns the SCMP peer manager-Id to this generated anonymous-subscriber. If you have assigned a subscriber template to the group, the anonymous subscribers generated have properties as defined by that template. If you have not assigned a subscriber template, the default template is used.
One SCE platform supports a maximum of 20 SCMP peer devices.
Connection Management
The SCMP attempts to maintain an open connection to each peer device.
The following figure illustrates the SCMP connection state functionality.
Figure 14-5 SCMP Connection State Functionality
The loss-of-sync timeout prevents the SCE platform from retaining sessions that are obsolete and whose identity-keys have been replaced or moved to other sessions thus miss-classification risk is limited.
SCMP Subscriber Management
Subscriber virtualization allows multiple SCMP peer devices to simultaneously manage subscribers in the SCE platform without interfering with each other. (Note that each device must handle a distinct set of subscribers and network IDs.)
The following mechanisms support subscriber virtualization:
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GUID and Subscriber ID
The SCMP requires the use of a globally unique identifier (GUID) that is created by and identifies each SCMP peer device. The GUID is a 16-character-long ASCII string. The SCE platform uses the GUID for all communication with the SCMP peer.
SCMP creates the SCE subscriber ID from the concatenation of any or all the following user-related RADIUS attributes, with the GUID as the suffix.
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The user defines this subscriber ID structure via CLI.
How to Configure the SCMP
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How to Configure SCMP Parameters
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You can configure the following options for the SCMP:
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How to Enable the SCMP
By default, the SCMP is disabled.
Step 1
scmpand press Enter.How to Disable the SCMP
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no scmpand press Enter.How to Configure the SCMP Peer Device to Push Sessions
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When SCMP establishes a connection with an SCMP peer device, it informs the device whether the SCMP is configured to push sessions or to wait till the sessions are pulled by the SCE platform.
Use this command to specify push mode. Use the no form of the command to specify pull mode. This configuration takes effect only after the connection is re-established.
Default is disabled (pull mode).
Step 1
scmp subscriber send-session-startand press Enter.How to Disable Pushing Sessions
Use this command to disable pushing sessions to the SCE platform. This means that the SCE platform will pull all sessions from the SCMP peer.
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no scmp subscriber send-session-startand press Enter.How to Configure the SCMP Peer Device to Force Each Subscriber to Single SCE Platform
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When SCMP establishes a connection with an SCMP peer device, it informs the device whether the SCMP is configured to allow each subscriber to be provisioned to only one SCE platform.
Use this command to configure the SCMP peer device to verify that each subscriber is provisioned to only one SCE platform. If a subscriber was provisioned to a different SCE platform, the SCMP removes it from the previous SCE platform and provisions it to the new SCE platform. This configuration is required in MGSCP topology where, if a fail-over between SCE platforms, subscribers might move from one SCE platform to another. If transferred subscribers are not cleared from the previous SCE platform, it can cause capacity issues.
Use the no form of the command to allow SCMP to provision subscribers to more than one SCE platform .
This configuration takes effect only after the connection is re-established.
Default is disabled (subscribers can be provisioned to more than one SCE platform).
Step 1
scmp subscriber force-single-sceand press Enter.How to Disable Forcing Each Subscriber to Single SCE Platform
Use this command to disable forcing each subscriber to only one SCE platform. This allow subscribers to be provisioned to more than one SCE platform.
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no scmp subscriber force-single-sceand press Enter.How to Define the Keep-alive Interval Parameter
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The keep-alive interval is the amount of time between keep-alive messages to the SCMP peer device. If the SCMP does not receive a response from the SCMP peer device within the defined interval, the connection is assumed to be down; and the SCMP changes the connection state to false and begins attempts to reconnect.
Options
The following options are available:
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Step 1
scmp keepalive-intervalintervaland press Enter.How to Define the Reconnect Interval Parameter
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The reconnect interval is the amount of time between attempts by the SCE platform to reconnect with an SCMP peer. The SCE platform attempts to reconnect to the SCMP peer device at the defined intervals by sending an establish-peering-request message.
Options
The following options are available:
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Step 1
scmp reconnect-intervalintervaland press Enter.How to Define the Loss-of-Sync Timeout Parameter
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The loss of sync timeout interval is the amount of time between loss of connection between the SCE platform and an SCMP peer device and the loss-of-sync event. (To prevent miss-classification, loss-of-sync event removes all subscribers that were provisioned by the relevant SCMP peer device.)
Options
The following options are available:
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Step 1
scmp loss-of-sync-timeoutintervaland press Enter.How to Add an SCMP Peer Device
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Adding an SCMP peer device is a two-step process:
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How to Define an SCMP Peer Device
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Options
The following options are available:
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Defaults:
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Step 1
scmp namepeer_device_nameradius radius_hostnamesecret shared_secret[auth-port auth-portnumberacct-port acct-portnumber] and press Enter.How to Assign the SCMP Peer Device to an Anonymous Group
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This command defines the specified anonymous group to be the IP range of the SCMP peer device. You must define the specified SCMP peer device before assigning the anonymous group.
Options
The following options are available:
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Step 1
subscriber anonymous-group namegroup-nameIP-range range[template template] scmp name peer-device-nameand press Enter.How to Remove an Anonymous Group from the SCMP Peer Device
This command defines the specified anonymous group to be the IP range of the SCMP peer device. You must define the specified SCMP peer device before assigning the anonymous group.
Step 1
no subscriber anonymous-group namegroup-nameand press Enter.How to Delete Subscribers Managed by an SCMP Peer Device
Use this command to clear all the subscribers that are managed by a specified SCMP peer device.
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Options
The following options are available:
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no subscriber scmp namepeer-device-nameall and press Enter.How to Delete an SCMP Peer Device
You cannot delete an SCMP peer device that has anonymous groups assigned to it. You must remove all associated anonymous groups before deleting the device.
SUMMARY STEPS
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DETAILED STEPS
Step 1
SCE(config if)# no subscriber anonymous-group name group-name [IP-range range ][template template ] scmp name peer-device-nameStep 2
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SCE(config if)# exitStep 4
SCE(config)#no scmp name peer_device_nameHow to Define the Subscriber ID
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You can define the structure of the subscriber ID via this command by specifying which of the following elements to include and in which order:
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The GUID is always appended at the end of the subscriber ID as defined by this command.
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Options
The following options are available:
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Default = no elements concatenated with the GUID
SUMMARY STEPS
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DETAILED STEPS
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SCE(config)#no scmpStep 2
SCE(config)#scmp subscriber id append-to-guid radius-attributes Calling-Station-Id | NAS-Port-Id | User-Name [Calling-Station-Id | NAS-Port-Id | User-Name] [Calling-Station-Id | NAS-Port-Id | User-Name]Step 3
SCE(config)#scmpHow to Configure the RADIUS Client
You can configure the following options for the RADIUS client
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The RADIUS client polls the sockets to receive the next message and calls the SCMP engine to handle it, based on the type of the received message. Messages that were not acknowledged can be retransmitted up to the configured maximum number of retries.
Options
The following options are available:
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Step 1
ip radius-client retry limittimes[timeout timeout] and press Enter.
How to Monitor the SCMP Environment
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You can monitor the following components of the SCMP environment:
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How to Monitor the SCMP
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Use the following commands to monitor the SCMP. These commands provide the following information:
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Options
The following options are available:
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How to display the general SCMP configuration
Step 1
show scmpand press Enter.Example
SCE>show scmp SCMP enabled: yes Keep-alive interval: 5 seconds Loss of synchronization timeout: 90 seconds from disconnection Reconnection interval: 30 seconds Force subscriber on a single SCE: no Peer sends subscriber data on session start Subscriber Id structure: GUIDHow to display the configuration all currently defined SCMP peer devices
Step 1
show scmp alland press Enter.How to display the configuration for a specified SCMP peer device
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show scmp namedevice-nameand press Enter.Example
SCE>show scmp name isg SCMP Connection 'isg' status: 10.56.208.91 auth-port 1812 acct-port 1813 Connection state: Connected Peer protocol-version: 1.0 Keep-alive interval: 5 seconds Force single SCE: No Send session start: Yes Time connected: 9 secondsHow to display the statistics for all SCMP peer devices
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show scmp all countersand press Enter.How to display the statistics for a specified SCMP peer device
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show scmp namepeer_device_namecounters and press Enter.Example
SCE>show scmp name isg counters SCMP Connection 'isg' counters: Total messages sent: 72 Total messages received: 72 Establish requests sent: 1 Establish replies received: 1 Accounting requests sent: 20 Accounting replies received: 20 Subscriber queries sent: 0 Subscriber query response recv: 0 Request retry exceeded: 0 Requests replied with errors: 0 Subscriber requests received: 50 Subscriber responses sent: 50 Failed Requests: 0 Keep-alive sent: 1 Keep-alive received: 1How to Monitor the RADIUS Client
Use the following command to monitor the SCMP RADIUS client. This command displays the general configuration of the RADIUS client.
Step 1
show ip radius-clientand press Enter.
Posted: Wed May 30 08:43:04 PDT 2007
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