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Table Of Contents
Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Restrictions for Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Information About Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Benefits of Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Memory Impact of Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Performance Impact of Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
How to Configure Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Specifying the Method for Selecting PVC Bundle Members
Configuring the QoS Group-Based Method for Selection of PVC Bundle Members
Configuring Explicit InARP PVC Selection for QoS Group-Based PVC Bundle Member Selection
Verifying Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Configuration Examples for Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Specifying the Method for Selecting PVC Bundle Members: Example
Configuring the QoS Group-Based Method for Selection of PVC Bundle Members: Example
Configuring Explicit InARP PVC Selection for QoS Group-Based PVC Bundle Member Selection: Example
qos-group (ATM VC bundle member)
Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
The Routed Bridge Encapsulation with ATM Virtual Circuit Bundles feature enables routed bridge encapsulation (RBE) over ATM permanent virtual circuit (PVC) bundles. This feature supports PVC bundle member selection based on the quality of service (QoS) group or on the type of service (ToS) or Multiprotocol Label Switching (MPLS) Experimental (EXP) bit in each packet over RBE interfaces. The PVC bundles carry RBE traffic configured on ATM point-to-point subinterfaces.
This feature also supports PVC bundle functionality for AAL5 MUX or LLC/SNAP encapsulations and ATM PVC bundle scalability.
History for the Routed Bridge Encapsulation with ATM Virtual Circuit Bundles Feature
12.4(4)T
This feature was introduced.
12.2(31)SB2
This feature was integrated into Cisco IOS Release 12.2(31)SB2.
Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Restrictions for Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
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Restrictions for Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
The following restrictions apply to the Routed Bridge Encapsulation with ATM Virtual Circuit Bundles feature:
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PVC bundles are supported under the following conditions (numbers are maximum per interface and per router):
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Information About Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
To configure the Routed Bridge Encapsulation with ATM Virtual Circuit Bundles feature, you should understand the following concepts:
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Benefits of Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
Without this feature, PVC bundle member selection is made based on ToS bit settings (for IP packets) or EXP bit settings (for MPLS packets). With this feature, you can make the PVC bundle member selection based on the QoS group value associated with the packet: on the ingress before route selection or on the egress after selecting the adjacency, the packet's pak_type header is marked with the QoS group to use based on the generic match criterion provided by the Modular QoS command line interface (MQC).
This feature gives you the flexibility to choose PVC bundle members based on various criteria. You can define any classification criterion for the traffic, mark the packets matching that criterion with the QoS group, and send them over a specific PVC bundle member to assign the appropriate quality of service to the corresponding class of traffic.
Memory Impact of Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
The additional memory required for this feature does not exceed 50 bytes per PVC bundle.
Performance Impact of Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
This feature slightly impacts forwarding path performance when PVC bundles are configured with QoS groups. This is because during forwarding, QoS groups must be mapped to the appropriate PVC bundle member index in the array of adjacencies associated with the PVC bundle adjacency.
This feature does not significantly increase CPU usage when traffic at line rates is sent over the PVC bundle (regardless of the selection criterion used for PVC bundle member selection).
How to Configure Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
This section describes how to configure the Routed Bridge Encapsulation with ATM Virtual Circuit Bundles feature. This section consists of the following configuration tasks:
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Specifying the Method for Selecting PVC Bundle Members
This section describes how to specify the method for selection of PVC bundle members. You can specify one of two selection methods:
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The selection methods are mutually exclusive. This means that when the selection method based on QoS groups is specified on any PVC bundle member, no other selection method is allowed on the same PVC bundle. Similarly, if the selection method based on ToS or EXP is specified on any PVC bundle member, no other selection method is allowed on the same PVC bundle.
Restrictions
You can change the selection method from QoS groups to ToS or EXP only if no PVC bundle member has QoS groups or Inverse Address Resolution Protocol (InARP) configured.
You can change the selection method from ToS or EXP to QoS groups only if no PVC bundle member has precedence, protection, or bumping configured.
SUMMARY STEPS
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DETAILED STEPS
Configuring the QoS Group-Based Method for Selection of PVC Bundle Members
This section describes how to configure the method for selection of PVC bundle members that is based on QoS groups. To do so, you associate a QoS group or groups with a PVC bundle member. You can specify a QoS group, a range of QoS groups, or any combination of QoS groups and ranges of QoS groups.
SUMMARY STEPS
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DETAILED STEPS
Configuring Explicit InARP PVC Selection for QoS Group-Based PVC Bundle Member Selection
This section describes how to configure explicit InARP for a PVC bundle member.
When InARP is enabled for a PVC bundle member, InARP requests are sent and are expected to be received on the PVC bundle member, and InARP replies are expected to be received on the PVC bundle member.
This procedure is optional and provides backward compatibility with existing PVC bundles, in which an InARP request is sent or expected to be received on the PVC bundle member with precedence 6. If a PVC bundle with selection based on QoS group is connected to an existing PVC bundle, you must follow this procedure to allow InARP to function. If you do not follow this procedure, InARP is sent over any of the available PVC bundle members.
Restrictions
You can enable InARP for a PVC bundle member only when using the QoS groups method for selecting PVC bundle members.
SUMMARY STEPS
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DETAILED STEPS
Verifying Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
To display information about routed bridge encapsulation with ATM virtual circuit bundles, use the following show commands in privileged EXEC mode. You can use these commands in any combination or order.
SUMMARY STEPS
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DETAILED STEPS
Configuration Examples for Routed Bridge Encapsulation with ATM Virtual Circuit Bundles
This section provides the following configuration examples:
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Specifying the Method for Selecting PVC Bundle Members: Example
The following example shows how to specify the method for selecting PVC bundle members:
interface atm 2/0bundle ciscoselection-method qos-grouppvc 1/32qos-group 1endConfiguring the QoS Group-Based Method for Selection of PVC Bundle Members: Example
The following example shows how to configure the QoS group-based method for selection of PVC bundle members:
interface atm 2/0bundle ciscoselection-method qos-grouppvc 1/32qos-group 1endConfiguring Explicit InARP PVC Selection for QoS Group-Based PVC Bundle Member Selection: Example
The following example shows how to configure explicit InARP PVC selection for QoS group-based PVC bundle member selection:
interface atm 2/0bundle ciscoselection-method qos-grouppvc 1/32qos-group 1inarp-vcendAdditional References
The following sections provide references related to the Routed Bridge Encapsulation with ATM Virtual Circuit Bundles feature.
Related Documents
QoS configuration
Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4T
QoS commands
Cisco IOS Quality of Service Solutions Command Reference, Release 12.4T
ATM configuration
Cisco IOS Asynchronous Transfer Mode Configuration Guide, Release 12.4
ATM commands
Cisco IOS Asynchronous Transfer Mode Command Reference, Release 12.4T
Standards
MIBs
None
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
Technical Assistance
Command Reference
This section documents new commands only.
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inarp-vc
To enable Inverse Address Resolution Protocol (InARP) for a permanent virtual circuit (PVC) bundle member, use the inarp-vc command in ATM VC bundle-member configuration mode. To disable InARP for a PVC bundle member, use the no form of this command.
inarp-vc
no inarp-vc
Syntax Description
This command has no arguments or keywords.
Command Default
InARP is disabled for the PVC bundle member.
Command Modes
ATM VC bundle-member configuration
Command History
12.4(4)T
This command was introduced.
12.2(31)SB2
This command was integrated into Cisco IOS Release 12.2(31)SB2.
Usage Guidelines
You can use this command only when using the quality of service (QoS) groups method for selecting the PVC bundle members. When InARP is enabled for a PVC bundle member, InARP requests are sent and are expected to be received on the PVC bundle member, and InARP replies are expected to be received on the PVC bundle member.
Examples
The following example associates QoS group 1 with a PVC bundle member and enables InARP on the PVC bundle member:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method qos-groupRouter(config-if-atm-bundle)# pvc 1/32Router(config-if-atm-member)# qos-group 1Router(config-if-atm-member)# inarp-vcRouter(config-if-atm-member)# endRelated Commands
qos-group (ATM VC bundle member)
Associates a QoS group or groups with a PVC bundle member.
selection-method
Specifies the method for selection of the PVC bundle member.
qos-group (ATM VC bundle member)
To associate a quality of service (QoS) group or groups with a permanent virtual circuit (PVC) bundle member, use the qos-group command in ATM VC bundle-member configuration mode. To disassociate a QoS group or groups from a PVC bundle member, use the no form of this command.
qos-group qos-groups
no qos-group qos-groups
Syntax Description
Command Default
No QoS groups are associated with the PVC bundle member.
Command Modes
ATM VC bundle-member configuration
Command History
12.4(4)T
This command was introduced.
12.2(31)SB2
This command was integrated into Cisco IOS Release 12.2(31)SB2.
Examples
The following example associates a single QoS group with a PVC bundle member:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method qos-groupRouter(config-if-atm-bundle)# pvc 1/32Router(config-if-atm-member)# qos-group 1Router(config-if-atm-member)# endThe following example associates a range of QoS groups from 1 to 5 with a PVC bundle member:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method qos-groupRouter(config-if-atm-bundle)# pvc 1/32Router(config-if-atm-member)# qos-group 1-5Router(config-if-atm-member)# endThe following example associates QoS groups 1 and 7 with a PVC bundle member:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method qos-groupRouter(config-if-atm-bundle)# pvc 1/32Router(config-if-atm-member)# qos-group 1,7Router(config-if-atm-member)# endThe following example associates a range of QoS groups 1 to 5 and a range of QoS groups 7-10 with a PVC bundle member:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method qos-groupRouter(config-if-atm-bundle)# pvc 1/32Router(config-if-atm-member)# qos-group 1-5,7-10Router(config-if-atm-member)# endRelated Commands
inarp-vc
Enables InARP for a PVC bundle member.
selection-method
Specifies the method for selection of the PVC bundle member.
selection-method
To specify the method for selection of permanent virtual circuit (PVC) bundle members, use the selection-method command in ATM VC bundle configuration mode. To disable a selection method, use the no form of this command.
selection-method {qos-group | tos-exp}
no selection-method {qos-group | tos-exp}
Syntax Description
Command Default
No selection method is set.
Command Modes
ATM VC bundle configuration
Command History
12.4(4)T
This command was introduced.
12.2(31)SB2
This command was integrated into Cisco IOS Release 12.2(31)SB2.
Usage Guidelines
You can change the selection method from QoS groups to ToS or EXP only if none of the PVC bundle members have QoS groups or Inverse Address Resolution Protocol (InARP) configured.
You can change the selection method from ToS or EXP to QoS groups only if none of the PVC bundle members have precedence, protection, or bumping configured.
Examples
The following example specifies the QoS groups selection method for a PVC bundle and associates a QoS group with a member of the PVC bundle:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method qos-groupRouter(config-if-atm-bundle)# pvc 1/32Router(config-if-atm-member)# qos-group 1Router(config-if-atm-member)# endThe following example specifies the ToS or EXP selection method for a PVC bundle:
Router> enablePassword:Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface atm 2/0Router(config-subif)# bundle ciscoRouter(config-if-atm-bundle)# selection-method tos-expRouter(config-if-atm-member)# endRelated Commands
inarp-vc
Enables InARP for a PVC bundle member.
qos-group (ATM VC bundle member)
Associates a QoS group or groups with a PVC bundle member.
Glossary
ARP—Address Resolution Protocol. Internet protocol used to map an IP address to a MAC address. Defined in RFC 826.
ATM—Asynchronous Transfer Mode. The international standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in fixed-length (53-byte) cells. Fixed-length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is designed to take advantage of high-speed transmission media, such as E3, SONET, and T3.
bundle—A logical grouping of one or more physical interfaces using the formats and procedures of multilink Frame Relay. A bundle emulates a physical interface to the Frame Relay data-link layer. The bundle is also referred to as the MFR interface.
CEF—Cisco Express Forwarding. Layer 3 IP switching technology that optimizes network performance and scalability for networks with large and dynamic traffic patterns.
fast switching—Cisco feature in which a route cache expedites packet switching through a router.
InARP—Inverse Address Resolution Protocol (ARP). Method of building dynamic routes in a network. Allows an access server to discover the network address of a device associated with a virtual circuit.
MPLS—Multiprotocol Label Switching. Switching method that forwards IP traffic using a label. This label instructs the routers and the switches in the network where to forward the packets based on preestablished IP routing information.
MQC—Modular QoS CLI (command line interface). A CLI structure that lets you create traffic polices and attach them to interfaces. A traffic policy contains a traffic class and one or more QoS features. A traffic class is used to classify traffic, and the QoS features in the traffic policy determine how to treat the classified traffic.
PVC—permanent virtual circuit (or connection). Virtual circuit that is permanently established. PVCs save bandwidth associated with circuit establishment and teardown in situations where certain virtual circuits must exist all the time. In ATM terminology, this is called a permanent virtual connection.
QoS—quality of service. Measure of performance for a transmission system that reflects its transmission quality and service availability.
RBE—routed bridge encapsulation. Process by which a stub-bridged segment is terminated on a point-to-point routed interface. Specifically, the router is routing on an IEEE 802.3 or Ethernet header carried over a point-to-point protocol, such as PPP, RFC 1483 ATM, or RFC 1490 Frame Relay.
SVC—switched virtual circuit. Virtual circuit that is dynamically established on demand and is torn down when transmission is complete. SVCs are used in situations where data transmission is sporadic. Called a switched virtual connection in ATM terminology.
ToS—type of service byte. Second byte in the IP header that indicates the desired quality of service for a specific datagram.
VC—virtual circuit. Logical circuit created to ensure reliable communication between two network devices. A VC is defined by a VPI/VCI pair and can be either permanent or switched.
Note
Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
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