Table Of Contents
Closed User Group Selection Facility
Suppress OptionSupported Standards, MIBs, and RFCs
Configuring CUG Selection Facility Suppression on an Interface
Configuring CUG Selection Facility Suppression on an X.25 Profile
Verifying CUG Selection Facility Suppression
Monitoring and Maintaining CUG Selection Facility Suppression
CUG Selection Facility Suppression for the Preferential CUG Configuration Example
CUG Selection Facility Suppression for All CUGs Configuration Example
Closed User Group Selection Facility
Suppress Option
This feature module describes the Closed User Group Selection Facility Suppress Option feature and includes the following sections:
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Supported Standards, MIBs, and RFCs
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Feature Overview
A closed user group (CUG) selection facility is a specific encoding element that can be presented in a call request or an incoming call. A CUG selection facility in a call request allows the source data terminal equipment (DTE) to identify the CUG within which it is placing the call. A CUG selection facility in an incoming call allows the destination DTE to identify the CUG to which both DTEs belong.
The Closed User Group Selection Facility Suppress Option feature enables a Cisco X.25 data communications equipment (DCE) interface or an X.25 profile with a DCE station type to selectively remove the CUG selection facility before presenting an incoming call packet to a subscribed DTE. CUG selection facility suppression applies to incoming calls only.
With this new feature, you can configure an X.25 DCE interface or X.25 profile to remove the CUG selection facility from incoming call packets destined for the preferential CUG only or for all CUGs. You can also remove the selection facility from a CUG with outgoing access (CUG/OA). The Closed User Group Selection Facility Suppress Option feature does not distinguish between CUGs and CUG/OAs.
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Benefits
Many legacy X.25 DTE devices cannot process the CUG selection facility in incoming call packets, so the devices reject the calls with the CUG selection facility. The Closed User Group Selection Facility Suppress Option feature allows Cisco X.25 DCE devices to remove the CUG selection facility before presenting the call to the DTE, enabling Cisco routers to operate transparently with existing legacy devices.
Restrictions
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Related Documents
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Supported Platforms
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Supported Standards, MIBs, and RFCs
Standards
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MIBs
No new or modified MIBs are supported.
For descriptions of supported MIBs and how to use MIBs, see the Cisco MIB web site on Cisco Connection Online (CCO) at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
No new or modified RFCs are supported.
Configuration Tasks
See the following sections for configuration tasks for the CUG Facility Selection Suppress Option feature. Each task in the list is identified as optional or required.
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Configuring CUG Selection Facility Suppression on an Interface
To configure the Closed User Group Selection Facility Suppress Option feature on an interface, use the following commands beginning in global configuration mode:
Configuring CUG Selection Facility Suppression on an X.25 Profile
To configure the Closed User Group Selection Facility Suppress Option feature on an X.25 profile, use the following commands beginning in global configuration mode:
Verifying CUG Selection Facility Suppression
To verify the Closed User Group Selection Facility Suppress Option feature, use the following privileged EXEC command:
Router# show x25 cug {local-cug number | network-cug number}
Displays information about all or specific CUGs.
Monitoring and Maintaining CUG Selection Facility Suppression
To monitor CUG Selection Facility Suppress Option, use one or both of the following privileged EXEC commands:
Configuration Examples
This section provides the following configuration examples:
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CUG Selection Facility Suppression for the Preferential CUG Configuration Example
In the following example, CUG selection facility suppression is configured for the preferential CUG only on serial interface 0:
interface serial0encapsulation x25 dcex25 subscribe cug-service suppress preferentialx25 subscribe local-cug 0 network-cug 10 preferentialx25 subscribe local-cug 50 network-cug 500CUG Selection Facility Suppression for All CUGs Configuration Example
In the following example, CUG selection facility suppression and incoming access are configured for all CUGs, including the preferential CUG on the X.25 profile:
x25 profile CUG-SUPRS-ALL dcex25 subscribe cug-service incoming-access suppress allx25 subscribe local-cug 0 network-cug 10 preferentialx25 subscribe local-cug 20 network-cug 202x25 subscribe local-cug 40 network-cug 40Command Reference
This section documents the modified commands that configure the Closed User Group Selection Facility Suppress Option feature.
show x25 cug
To display information about all closed user groups (CUGs) or specific CUGs (defined by the local or network CUG number), use the show x25 cug EXEC command.
show x25 cug {local-cug number | network-cug number}
Syntax Description
local-cug
Locally significant CUG identifier.
number
Local CUG number (0 to 9999).
network-cug
Network translated CUG identifier.
number
Network CUG number (0 to 9999).
Command Modes
EXEC
Command History
12.0(7)T
This command was introduced.
12.1(5)T
This command was modified to show information about CUG selection facility suppression.
Usage Guidelines
You must designate either the local-cug or the network-cug keyword with this command. Within these designations you can view all CUGs or a specific CUG defined by its local or network CUG identifier.
Examples
CUG Selection Facility Suppress Option Example
The following is sample output for the show x25 cug command when CUG selection facility is suppressed for all CUGs on serial interface 1/2 and for the preferential CUG on the X.25 profile named "cug".
Router# show x25 cug local-cugX.25 Serial1/2, 2 CUGs subscribed with no public accessCUG selection facility suppressed for all CUGslocal-cug 100 <-> network-cug 10local-cug 1 <-> network-cug 11PROFILE cug, 2 CUGs subscribed with incoming public accessCUG selection facility suppressed for preferential CUGlocal-cug 0 <-> network-cug 0 , preferentiallocal-cug 100 <-> network-cug 100local-cug 200 <-> network-cug 200Local CUG Example
The following is sample output from the show x25 cug local-cug command, displaying information about all local CUGs on X.25 serial interface 0. Four CUGs have been subscribed to on serial interface 0, and they all have been configured for incoming and outgoing public access.
Router# show x25 cug local-cugX.25 Serial0, 4 CUGs subscribed with incoming and outgoing public accesslocal-cug 100 <-> network-cug 11local-cug 200 <-> network-cug 22local-cug 300 <-> network-cug 33local-cug 5000 <-> network-cug 55, preferentialNetwork CUG Example
The following is sample output from the show x25 cug network-cug command specifically for network number 33 showing that local CUG 300 is associated with it.
Router# show x25 cug network-cug 33X.25 Serial1/2, 5 CUGs subscribed with no public accessnetwork-cug 33 <-> local-cug 300Table 1 describes the fields shown in the display for the show x25 cug command.
Related Commands
Enables and controls standard CUG behavior on an X.25 DCE interface.
x25 subscribe local-cug
Configures a DCE X.25 interface for a specific CUG subscription.
x25 subscribe cug-service
To enable and control standard closed user group (CUG) behavior on an X.25 DCE interface or X.25 profile, use the x25 subscribe cug-service interface configuration command. To disable standard CUG behavior on an X.25 DCE interface, use the no form of this command.
x25 subscribe cug-service [incoming-access | outgoing-access] [suppress preferential | suppress all]
no x25 subscribe cug-service [incoming-access | outgoing-access] [suppress preferential | suppress all]
Syntax Description
Defaults
No incoming access and no outgoing access. (This is the most restrictive setting.)
CUG selection facilities are not suppressed.
Command Modes
Interface configuration
X.25 profile configuration mode
Command History
12.0(7)T
This command was introduced.
12.1(5)T
The suppress preferential and suppress all keywords were added to enable CUG selection facility suppression.
Usage Guidelines
When entering this command, specify either the incoming-access or the outgoing-access keyword, unless you intend to have neither incoming nor outgoing access on that interface.
This command assumes that an X.25 network connection is being implemented and observes rules defined by X.25 and X.301 for CUG access. This command is enabled on a per-interface basis. Use this command to modify existing specified options without otherwise affecting the CUGs already defined.
The following restrictions apply to the x25 subscribe cug-service command:
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Examples
CUG Service with CUG Selection Facility Suppression and Incoming Access Example
In the following example, CUG selection facility suppression and incoming access are configured for all CUGs, including the preferential CUG on the X.25 profile:
x25 profile CUG-SUPRS-ALL dcex25 subscribe cug-service incoming-access suppress allx25 subscribe local-cug 0 network-cug 10 preferentialx25 subscribe local-cug 20 network-cug 202x25 subscribe local-cug 40 network-cug 40CUG Service with Incoming and Outgoing Access Example
The following example shows subscribing to both incoming and outgoing CUG service on the interface:
interface serial0encapsulation x25 dcex25 subscribe cug-service incoming-access outgoing-accessRelated Commands
Glossary
call request—An X.25 call packet sent from a DTE to a DCE that initiates a connection to a destination DTE.
closed user group—A collection of DTE devices for which the network controls access between members and between members and nonmembers. A DTE may subscribe to zero, one, or more CUGs. A DTE that does not subscribe to a CUG is referred to as being in the open part of the network.
closed user group selection facility—A specific encoding element that can be presented in a call request or incoming call. A CUG selection facility in a call request allows the source DTE to identify the CUG within which it is placing the call. A CUG selection facility in an incoming call allows the destination DTE to identify the CUG to which both DTEs belong.
closed user group with outgoing access (CUG/OA)—A CUG that allows subscribing DTEs to place calls to the open part of the network.
CUG—See closed user group.
CUG/OA—See closed user group with outgoing access.
DTE—data terminal equipment. A network subscriber that can be reached at a specific network attachment point. A network identifies each DTE by assigning an X.121 address.
DCE—data communications equipment. A network connection where a subscriber can be attached. A DCE is configured with the operational details that a given subscriber (DTE) has contracted for.
incoming call—An X.25 call packet sent from a DCE to a DTE that presents a connection requested by the source DTE.
preferential closed user group—The CUG that is assumed when a CUG is not specified in call setup. A DTE that subscribes to more than one CUG and does not have incoming or outgoing access must designate a preferential CUG.
Guest
