Table Of Contents
Related Features and Technologies
Supported Standards, MIBs, and RFCs
Configuring Service-Specific TCP Redirect
Configuring Traffic Status During Reauthorization
Verifying SSG Prepaid Idle Timeout
Monitoring and Maintaining SSG Prepaid Idle Timeout
Configuring SSG Prepaid Example
Configuring TCP Redirect Example
Configuring Service-Specific TCP Redirect Example
Configuring a Threshold Value Examples
Configuring Traffic Status During Reauthorization Example
ssg prepaid reauthorization drop-packet
SSG Prepaid Idle Timeout
Feature History
Release Modification12.2(15)B
This feature was introduced.
12.3(4)T
This feature was integrated into Cisco IOS Release 12.3(4)T.
This document describes the SSG Prepaid Idle Timeout feature and includes the following sections:
•Supported Standards, MIBs, and RFCs
•Monitoring and Maintaining SSG Prepaid Idle Timeout
Feature Overview
SSG
Service Selection Gateway (SSG) is a switching solution for service providers who offer intranet, extranet, and Internet connections to subscribers using broadband access technology such as xDSL, cable modems, or wireless to allow simultaneous access to network services.
For more information about SSG, refer to the Service Selection Gateway document.
SSG Prepaid
The SSG Prepaid feature allows SSG to check a subscriber's available credit to determine whether to connect the subscriber to a service and how long the connection can last. The subscriber's credit is administered by the billing server as a series of quotas representing either a duration of use (in seconds) or an allowable data volume (in bytes). A quota is an allotment of available credit.
To obtain the first quota for a connection, SSG submits an authorization request to the authentication, authorization, and accounting (AAA) server. The AAA server contacts the prepaid billing server, which forwards the quota values to SSG. SSG then monitors the connection to track the quota usage. When the quota runs out, SSG performs reauthorization. During reauthorization, the billing server may provide SSG with an additional quota if there is available credit. If no further quota is provided, SSG logs the user off.
SSG Prepaid Idle Timeout
The SSG Prepaid Idle Timeout feature enhances the SSG Prepaid feature by enabling SSG to return residual quota to the billing server from services that a user is logged into but not actively using. The quota that is returned to the billing center can be applied to the quota for the services that the user is actively using.
When SSG is configured for SSG Prepaid Idle Timeout, a user's connection to services can be open even when the billing server returns a zero quota, but the connection's status is dependent on the combination of the quota and the idle timeout value returned. Depending on the connection service, SSG requests the quota for a connection from the billing server once the user starts using a particular service, when the user runs out of quota, or after the configured idle timeout value has expired.
The SSG Prepaid Idle Timeout feature enhances handling of a returned zero quota from the billing server. If a billing server returns a zero quota and a nonzero idle timeout, this indicates that a user has run out of credit for a service. When a user runs out of credit for a service, the user is redirected to the billing server to replenish the quota. When the user is redirected to the billing server, the user's connection to the original service or services is retained. Although the connection remains up, any traffic passing through the connection is dropped. This enables a user to replenish quota on the billing server without losing connections to services or having to perform additional service logons.
Using the SSG Prepaid Idle Timeout feature, you can configure SSG to reauthorize a user before the user completely consumes the allocated quota. You can also configure SSG to drop traffic during reauthorization. This prevents revenue leaks in the event that the billing server returns a zero quota for the user. Without the SSG Prepaid Idle Timeout feature, traffic passed during reauthorization represents a revenue leak if the billing server returns a zero quota for the user. You can prevent this type of revenue leak by configuring a threshold value, causing SSG to reauthorize a user's connection before the user completely consumes the allocated quota for a service.
SSG Prepaid Idle Timeout enhances SSG to inform the billing server upon any connection failure. This enables the billing server to free quota that was reserved for the connection that failed and to apply this quota immediately to some other active connection.
Service Authorization
SSG sends a service authorization request to the billing server upon initial service authorization. Explicit service authorization is required whenever a user attempts to connect to a prepaid service to ensure that the user has sufficient credit to connect to that service. The billing server responds with the available quota to SSG. If the returned available quota is greater than zero (or not present), SSG allows the user to connect to the service and begins metering using the allotted quota. For this service authorization, an Access-Request packet is generated once the service is identified as a prepaid service. The Access-Request is generated for service authorization regardless of the service type (pass-through, proxy, tunnel, or virtual private dial-up network [VPDN]). Table 1 describes this Access-Request.
Table 1 Contents of Service Authorization Access-Request
Attribute Number Attribute Name Description Notes1
User-Name1
MS subscriber name
2
PAP Password
Global service profile password
4
NAS IP Address
SSG IP address
6
Service-Type
Framed-user
7
Framed Protocol
Framed protocol
26
Vendor-Specific
Name of service
Subattribute ID 251; code N.
31
Calling-Station-ID
MSISDN2
44
Acct-Session-ID
Session ID
61
NAS-Port-Type
Async (value=0)
1 The User-Name is the name of the subscriber and not the name of the service. The name of the service is indicated by the Service Name VSA.
2 The Calling-Station-ID attribute is for additional user identification and is optional. This attribute is present only if the corresponding host object on SSG contains this information. The Calling-Station-ID attribute is used for hosts in mobile wireless environments and SESM 3-Key users.
The billing server responds to the service authorization Access-Request packet with an Access-Accept packet that defines the quota parameters for the connection. Table 2 describes the Access-Accept for a service authorization request. Authorization for a service is provided according to the presence and content of the Quota (Attribute 26) and the Idle Timeout (Attribute 28) vendor-specific attributes (VSAs) in the Access-Accept.
The Quota VSA in the service profile has been enhanced to inform the billing server of the reason for the reauthorization request. Table 3 describes the enhanced Quota VSA.
Table 4 and Table 5 summarize the action performed by SSG as a result of the attributes included in the billing server's answer to the service authorization or service reauthorization request.
In time-based quotas, if the traffic on a connection is dropped during reauthorization because the ssg prepaid reauthorization drop-packet command is configured, the time used during the reauthorization is not accounted to that connection. The reauthorization times are deducted from the total session duration while SSG sends the Account Session Time (Attribute 46) in the Accounting Stop and Update packets.
If the billing server responds with a time-based connection to redirect traffic, TCP traffic is redirected. The duration of the TCP redirection is also not accounted to the user's connection.
Service Reauthorization
SSG sends a service reauthorization request to the billing server when a prepaid user's quota is consumed, after the configured idle timeout expires, or when the user's remaining quota reaches the configured threshold value.
Using SSG Prepaid Idle Timeout, service providers can configure how traffic is handled during reauthorization. By default, traffic continues during reauthorization. If the billing sever returns a zero quota in the reauthorization response, the connection is terminated, but the data that was in progress during the reauthorization goes through and is not accounted. You can configure SSG to either drop or forward traffic during reauthorization. You can also configure a threshold value, which configures SSG to reauthorize a connection with the billing server before a prepaid user's allocated quota is completely consumed.
Table 6 describes the contents of a service reauthorization request.
The reauthorization request for SSG Prepaid Idle Timeout is similar to the reauthorization request for SSG Prepaid. The SSG Prepaid Idle Timeout reauthorization request contains an additional attribute, Reauthorization Reason. If this attribute is not present, the billing server assumes that the reason for the reauthorization request is Primary Quota Consumed. The value of the Reauthorization Reason attribute can be Quota Consumed (QR0) or Idle Timer Expired (QR1).
Benefits
Concurrent Service Access
The SSG Prepaid solution is capable of supporting concurrent service access. SSG services can be configured for concurrent or sequential access. Concurrent access allows users to log on to a service while simultaneously connected to other services. Sequential access requires that the user log off from all other services before accessing a service.
Real-Time Billing
The SSG Prepaid feature allows for real-time billing with maximum flexibility, regardless of the type of service and billing scheme. Users can be billed on a flat rate, air-time, or volume basis.
Redirection Upon Exhaustion of Quota
When a user runs out of quota, SSG can redirect the user to a portal where the user can replenish the quota without being disconnected from the service.
Returning Residual Quota
The SSG Prepaid Idle Timeout feature enhances the SSG Prepaid feature by enabling SSG to return residual quota to the billing server from services that a user is logged into but not actively using. The quota that is returned to the billing server can be applied to the quota for the services that the user is actively using.
Threshold Values
The SSG Prepaid Idle Timeout feature can prevent revenue leaks by enabling you to configure a threshold value. Configuring a threshold value causes user connections to be reauthorized before the user completely consumes the allotted quota for a service.
Traffic Status During Reauthorization
You can prevent revenue leaks by configuring SSG to drop connected traffic during reauthorization of a service. The user remains connected to the service and does not need to log back onto the service, but no traffic is forwarded during the reauthorization process. This prevents a user from continuing to use a service for which they have run out of quota while the SSG sends a reauthorization request to the billing server. If you configure SSG to drop traffic during reauthorization and configure a threshold value, user traffic continues until the user exhausts the allotted quota. When the allotted quota is used, the traffic is dropped until SSG receives a reauthorization response.
Restrictions
•Quotas are measured in seconds for time or bytes for volume. There is no way to change the unit of measure.
•The volume quota is for combined upstream and downstream traffic.
•Simultaneous time and volume quotas for the same service connection are not supported.
•Returning quota when the connection is idle is supported only for volume-based connections and is not supported for time-based connections.
•When a user has run out of quota and replenished the quota at the billing server, SSG receives the updated quota and resumes the connection only after the next reauthorization.
Related Features and Technologies
•Mobile wireless
•RADIUS
•Service Selection Gateway (SSG)
•SSG Prepaid
Related Documents
•The "Configuring RADIUS" chapter in the Cisco IOS Security Configuration Guide
•Cisco IOS Security Command Reference, Release 12.3 T
•SSG AutoLogon Using Proxy Radius
•SSG Accounting Update Interval per Service
•SSG TCP Redirect for Services
Supported Platforms
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Supported Standards, MIBs, and RFCs
Standards
No new or modified standards are supported by this feature.
MIBs
No new or modified MIBs are supported by this feature.
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
No new or modified RFCs are supported by this feature.
Prerequisites
•You must enable SSG accounting in order for the SSG Prepaid feature to be used. SSG accounting is enabled by default. If it has been disabled, reenable it by using the ssg accounting command in global configuration mode.
•The SSG Prepaid feature requires the AAA server to have prepaid billing support.
•You must configure SSG to send Attribute 55 in accounting requests.
Configuration Tasks
See the following sections for configuration tasks for the SSG Prepaid Idle Timeout feature. Each task in the list is identified as either required or optional.
•Configuring SSG Prepaid (required)
•Configuring TCP Redirect (required)
•Configuring Service-Specific TCP Redirect (optional)
•Configuring a Threshold Value (optional)
•Configuring Traffic Status During Reauthorization (optional)
Configuring SSG Prepaid
To configure SSG to provide the prepaid billing server with session ID and time-stamp information, use the following commands in global configuration mode:
Configuring TCP Redirect
To configure SSG to redirect a user's TCP traffic to a prepaid portal when the user runs out of quota on the billing server, use the following commands beginning in global configuration mode:
Configuring Service-Specific TCP Redirect
To redirect all prepaid users that are connected to a particular service to a specific port, enter the following commands beginning in global configuration mode:
Configuring a Threshold Value
To configure SSG to reauthorize a prepaid user's connection before the user has completely consumed the allotted quota for a service, you can configure a threshold value. Configure either a time-based or a volume-based threshold value by entering the following commands in global configuration mode:
Configuring Traffic Status During Reauthorization
To configure SSG to drop traffic during reauthorization if threshold values are not configured, use the following command in global configuration mode:
Command PurposeRouter(config)# ssg prepaid reauthorization drop-packet
Configures SSG to drop traffic during reauthorization, when threshold values are not configured.
Note When threshold values are configured, traffic is dropped during reauthorization after a user completely exhausts the allotted quota and before SSG gets a reauthorization response from the billing server.
Verifying SSG Prepaid Idle Timeout
To verify the configuration of the SSG Prepaid Idle Timeout feature, use the following commands:
Step 1 Enter the show ssg connection command to display information about the host's connection to the specified service, including quota information for prepaid connections.
The following output is displayed for a user who fulfills the volume quota without any idle timeouts:
Router# show ssg connection 172.16.0.0 Internet
------------------------ConnectionObject Content -----------------------User Name:quserOwner Host:172.16.0.0Associated Service:InternetConnection State:0 (UP)Connection Started since:*01:45:09.000 GMT Thu Oct 9 2003User last activity at:*01:45:09.000 GMT Thu Oct 9 2003Connection Traffic Statistics:Prepaid quota:Session policing disabledThe following output is displayed for a user who has a zero or nonzero volume quota with nonzero idle timeout:
Router# show ssg connection 172.16.0.0 Internet------------------------ConnectionObject Content -----------------------User Name:quserOwner Host:172.16.0.0Associated Service:InternetConnection State:0 (UP)Connection Started since:*02:29:09.000 GMT Thu Oct 9 2003User last activity at:*02:30:14.000 GMT Thu Oct 9 2003Connection Traffic Statistics:Input Bytes = 4000, Input packets = 40Output Bytes = 4000, Output packets = 40Prepaid quota:Quota Type = 'VOLUME', Quota Value = 11200Timeout Value = 60Session policing disabledThe following output is displayed for a user who has a zero volume quota with zero idle timeout:
Router# show ssg connection 172.16.0.0 Internet------------------------ConnectionObject Content -----------------------User Name:quserOwner Host:172.16.0.0Associated Service:InternetConnection State:0 (UP)Connection Started since:*02:29:09.000 GMT Thu Oct 9 2003User last activity at:*02:31:11.000 GMT Thu Oct 9 2003Connection Traffic Statistics:Input Bytes = 4800, Input packets = 48Output Bytes = 4900, Output packets = 49Prepaid quota:Quota Type = 'VOLUME', Quota Value = 9700Timeout Value = 0Session policing disabledThe following output is displayed when a user receives a time quota:
Router# show ssg connection 172.16.0.0 Internet------------------------ConnectionObject Content -----------------------User Name:quserOwner Host:172.16.0.0Associated Service:InternetConnection State:0 (UP)Connection Started since:*02:35:51.000 GMT Thu Oct 9 2003User last activity at:*02:35:51.000 GMT Thu Oct 9 2003Connection Traffic Statistics:Input Bytes = 0, Input packets = 0Output Bytes = 0, Output packets = 0Prepaid quota:Quota Type = 'TIME', Quota Value = 30Session policing disabledThe following output is displayed when a user receives a zero time quota with idle timeout:
Router# show ssg connection 172.16.0.0 Internet------------------------ConnectionObject Content -----------------------User Name:quserOwner Host:172.16.0.0Associated Service:InternetConnection State:0 (UP)Connection Started since:*02:38:20.000 GMT Thu Oct 9 2003User last activity at:*02:38:20.000 GMT Thu Oct 9 2003Connection Traffic Statistics:Input Bytes = 0, Input packets = 0Output Bytes = 0, Output packets = 0Prepaid quota:Quota Type = 'TIME', Quota Value = 0Timeout Value = 60Session policing disabledStep 2 Enter the show ssg service command to display the redirect group configured for a service:
Router# show ssg service Internet------------------------ ServiceInfo Content -----------------------Uplink IDB: gw:10.0.0.0Name:InternetType:PASS-THROUGHMode:CONCURRENTService Session Timeout:0 secondsService Idle Timeout:0 secondsService refresh timeleft:102 minutesAuthorization RequiredAuthorization RequiredAuthentication Type:CHAPReference Count:1DNS Server(s):No Radius server group created. No remote Radius servers.Prepaid Redirect Service Group = InternetRedirectGroup ! Service-specific redirect group
Included Network Segments:172.16.0.0/255.255.0.0Excluded Network Segments:ConnectionCount 1Full User Name not usedDomain List:Active Connections:1 :RealIP=10.0.0.0, Subscriber=172.18.0.2------------------------ End of ServiceInfo Content ----------------Step 3 Enter the show ssg tcp-redirect group command to display the configured redirect server groups. The output displayed shows two configured redirect groups. The redirect default group called "DefaultRedirectGroup" is used to redirect prepaid connections when a user runs out of quota, and the corresponding service is not configured with any service-specific redirect group:
Router# show ssg tcp-redirect groupCurrent TCP redirect groups:InternetRedirectGroupDefaultRedirectGroup! The default redirect group is used to redirect prepaid connections when the user runs out of quota and the corresponding service is not configured with any service-specific redirect group.Unauthenticated user redirect group:None SetDefault service redirect group:None SetPrepaid user default redirect group:DefaultRedirectGroupSMTP forwarding group:None SetDefault initial captivation group:None SetDefault advertising captivation group:None SetStep 4 Enter the show running-config command to display the contents of the current running configuration:
Router# show running-config...ssg prepaid reauthorization drop-packetssg prepaid threshold volume 2000ssg prepaid threshold time 10...ssg tcp-redirectserver-group InternetRedirectGroupserver 9.2.36.253 8080server 9.2.36.100 80!server-group DefaultRedirectGroupserver 10.0.0.1 8080server 10.0.0.20 80!redirect prepaid-user to DefaultRedirectGroup...
Troubleshooting Tips
To display all debug TCP redirect information, use the debug ssg tcp-redirect command.
Monitoring and Maintaining SSG Prepaid Idle Timeout
To monitor and maintain SSG Prepaid Idle Timeout functionality, use the following commands in privileged EXEC mode:
Configuration Examples
This section provides the following configuration examples:
•Configuring SSG Prepaid Example
•Configuring TCP Redirect Example
•Configuring Service-Specific TCP Redirect Example
•Configuring a Threshold Value Examples
•Configuring Traffic Status During Reauthorization Example
Configuring SSG Prepaid Example
The following example shows how to configure SSG to provide the prepaid billing server with session ID and time-stamp information:
radius-server attribute 44 include-in-access-reqradius-server attribute 55 include-in-acct-reqConfiguring TCP Redirect Example
The following example shows how to configure a captive portal group called "DefaultRedirectGroup", add two servers to "DefaultRedirectGroup", and redirect prepaid users to the newly created captive portal:
ssg enablessg tcp-redirectserver-group DefaultRedirectGroupserver 10.0.0.1 8080server 10.0.0.20 80endredirect prepaid-user to DefaultRedirectGroupConfiguring Service-Specific TCP Redirect Example
The following example shows how to redirect all prepaid service traffic to the captive portal group called "InternetRedirectGroup" and to configure the captive portal group as the server group used for redirecting prepaid traffic:
ssg enablessg tcp-redirectserver-group InternetRedirectGroupserver 10.0.0.1 8080server 10.0.0.20 80endService Profile for InternetRedirectGroup
ServiceInfo="Z"Configuring a Threshold Value Examples
The following example shows how to configure a threshold time value of 10 seconds:
ssg prepaid threshold time 10The following example shows how to configure a threshold volume value of 2000 bytes:
ssg prepaid threshold volume 2000Configuring Traffic Status During Reauthorization Example
The following example shows how to configure SSG to drop traffic during reauthorization:
ssg prepaid reauthorization drop-packetCommand Reference
This section documents new commands. All other commands used with this feature are documented in the Cisco IOS Release 12.3 T command reference publications.
•ssg prepaid reauthorization drop-packet
redirect prepaid-user to
To configure a captive portal group for redirection of prepaid user traffic, use the redirect prepaid-user to command in SSG-redirect configuration mode. To configure SSG not to redirect prepaid users to the specified captive portal group, use the no form of this command.
redirect prepaid-user to group-name
no redirect prepaid-user to group-name
Syntax Description
Defaults
If no redirect group is configured, prepaid traffic is dropped.
Command Modes
SSG-redirect
Command History
Release Modification12.2(15)B
This command was introduced.
12.3(4)T
This command was integrated into Cisco IOS Release 12.3(4)T.
Usage Guidelines
Use this command to configure and name a captive portal group to which prepaid user traffic is redirected. When a user that is logged on to a prepaid service runs out of quota on the billing server, the user is redirected to the configured captive portal group if the service is not configured with any specific redirect server group. Once redirected to the captive portal group, the user can refill the quota on the billing server without being disconnected from the original prepaid service.
The captive portal group is the default group for all services that are not configured with a redirect group.
Examples
The following example shows how to configure a captive portal group called "DefaultRedirectGroup", add two servers to "DefaultRedirectGroup", and redirect prepaid users to the newly created captive portal:
ssg enablessg tcp-redirectserver-group DefaultRedirectGroupserver 10.0.0.1 8080server 10.0.0.20 80endredirect prepaid-user to DefaultRedirectGroupRelated Commands
ssg prepaid reauthorization drop-packet
To configure Service Selection Gateway (SSG) to drop prepaid traffic during reauthorization if threshold values are not configured, use the ssg prepaid reauthorization drop-packet command in global configuration mode. To configure SSG to forward traffic during reauthorization and not to drop traffic during reauthorization, use the no form of this command.
ssg prepaid reauthorization drop-packet
no ssg prepaid reauthorization drop-packet
Syntax Description
This command has no arguments or keywords.
Defaults
SSG forwards traffic during reauthorization by default.
Command Modes
Global configuration
Command History
Release Modification12.2(15)B
This command was introduced.
12.3(4)T
This command was integrated into Cisco IOS Release 12.3(4)T.
Usage Guidelines
SSG sends a service reauthorization request to the billing server when a prepaid user's quota is consumed or after the configured idle timeout expires. If the billing sever returns a zero quota in the reauthorization response, the connection is disconnected, but the data that was in progress during the reauthorization is not counted in the reauthorization.
Use this command to configure how traffic is handled during reauthorization. This command configures SSG to drop all prepaid user traffic during reauthorization when threshold values are not configured. If you configure SSG to drop traffic during reauthorization and a threshold value is configured, traffic is not dropped during reauthorization until the user exhausts the allotted quota. If a user exhausts the allotted quota, traffic gets dropped until SSG receives the reauthorization response. By default, traffic continues during reauthorization.
Use the no ssg prepaid reauthorization drop-packet command to configure SSG not to drop any traffic during reauthorization.
Examples
The following example shows how to configure SSG to drop traffic during reauthorization:
ssg prepaid reauthorization drop-packetRelated Commands
Command DescriptionConfigures SSG to reauthorize a prepaid user's connection when the user's remaining quota reaches the configured threshold value.
ssg prepaid threshold
To configured a Service Selection Gateway (SSG) prepaid threshold value, use the ssg prepaid threshold command in global configuration mode. To disable the SSG prepaid threshold value, use the no form of this command.
ssg prepaid threshold {volume bytes | time seconds}
no ssg prepaid threshold {volume bytes | time seconds}
Syntax Description
Defaults
No SSG prepaid threshold values are configured, and reauthorization happens only after a user has completely exhausted the allotted quota.
Command Modes
Global configuration
Command History
Release Modification12.2(15)B
This command was introduced.
12.3(4)T
This command was integrated into Cisco IOS Release 12.3(4)T.
Usage Guidelines
Use this command to configure an SSG prepaid threshold value. By default, SSG reauthorizes a prepaid user's connection only after the user's allotted quota has been consumed. When a prepaid threshold value is configured, SSG reauthorizes a prepaid user's connection before the user has completely consumed the allotted quota for a service.
For a prepaid threshold time configuration, the threshold time is in seconds and should be configured to be at least equal to the connection reauthorization time.
For a prepaid threshold volume configuration, the threshold volume is in bytes and should be at least equal to the user's bandwidth multiplied by the reauthorization time. Calculate the prepaid threshold volume value using the following formula:
TH >= BW * T
TH (bytes) = threshold value
BW (Bps) = user's bandwidth
T (seconds) = reauthorization time
Examples
The following example shows how to configure a threshold time value of 10 seconds:
ssg prepaid threshold time 10The following example shows how to configure a threshold volume value of 2000 bytes:
ssg prepaid threshold volume 2000Related Commands
Glossary
Access-Accept—Response packet from the RADIUS server notifying the access server that the user is authenticated. This packet contains the user profile, which defines the specific AAA functions assigned to the user.
Access-Request—Request packet sent to the RADIUS server by the access server requesting authentication of the user.
SESM—Subscriber Edge Services Manager. The SESM is part of a Cisco solution that allows subscribers of digital subscriber line (DSL), cable, wireless, and dial-up to simultaneously access multiple services provided by different Internet service providers, application service providers, and corporate access servers.
SSG—Service Selection Gateway.
VPDN—virtual private dial-up network. A VPDN is a network that extends remote access to a private network using a shared infrastructure. VPDNs use Layer 2 tunnel technologies (L2F, L2TP, and PPTP) to extend the Layer 2 and higher parts of the network connection from a remote user across an Internet service provider (ISP) network to a private network.
VSA—vendor-specific attribute. An attribute that has been implemented by a particular vendor. It uses the attribute Vendor-Specific to encapsulate the resulting attribute-value (AV) pair.
Note Refer to Internetworking Terms and Acronyms for terms not included in this glossary.
Copyright © 2003 Cisco Systems, Inc. All rights reserved.