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Table Of Contents
Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
PPP over ATM Configuration Scenario
Benefits of Autosense for ATM PVCs
How to Provide Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
Configuring IETF-Compliant MUX Encapsulated PPP over ATM
Configuring IETF-Compliant LLC Encapsulated PPP over ATM
Configuring Cisco-Proprietary PPP over ATM PVCs
Configuring SVCs for NAPs and NSPs
Configuring PPPoA Autosense for a Single PVC
Configuring PPPoA Autosense for a VC Class
Verifying PPPoA Autosense for ATM PVCs
Configuration Examples for Configuring PPP over ATM
IETF-Compliant MUX Encapsulated PPP over ATM Configuration: Examples
IETF-Compliant PPP over ATM with Different Traffic-Shaping Parameters: Example
Two Routers with Back-to-Back PVCs: Example
Multiplexed Encapsulation Using VC Class: Example
IETF-Compliant LLC Encapsulated PPP over ATM Configuration: Examples
Configuring IETF-Compliant PPP over ATM LLC Encapsulation: Example
Overriding a Virtual Template for IETF-Compliant PPP over ATM: Example
Disabling IETF-Compliant PPP over ATM LLC Encapsulation on a Specific VC: Example
Cisco Proprietary-PPP-over-ATM: Example
PPP over an ATM SVC Configuration: Example
PPPoA/PPPoE Autosense on an ATM PVC: Example
PPPoA/PPPoE Autosense on a VC Class: Example
PPPoA/PPPoE Autosense on Multiple VC Classes and
Virtual Templates: Example
Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
First Published: May 2, 2005Last Updated: Feb 18, 2009PPP over ATM enables a high-capacity central site router with an ATM interface to terminate multiple remote PPP connections. PPP over ATM provides security validation per user, IP address pooling, and service selection capability.
FFinding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for <Phrase Based on Module Title>" section on page 7.
Use Cisco Feature Navigator to find information about platform support and Cisco 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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How to Provide Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
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Prerequisites for Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
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Restrictions for Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
PPP over ATM cannot be configured on IETF-compliant Logical Link Control (LLC) encapsulated PPP over ATM.
Information About Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
This section describes the following concepts:
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PPP over ATM Configuration Scenario
PPP over ATM can be configured on all platforms running Cisco IOS Release 12.1 or later.
Note
Figure 2 shows a typical scenario for using Cisco-proprietary PPP over ATM.
Figure 2 PPP-over-ATM Network Environment
Note
Virtual Access Interface
When you configure PPP over ATM, a logical interface known as a virtual access interface associates each PPP connection with an ATM VC. You can create this logical interface by configuring an ATM permanent virtual circuit (PVC) or switched virtual circuit (SVC). This configuration encapsulates each PPP connection in a separate PVC or SVC, allowing each PPP connection to terminate at the router ATM interface as if received from a typical PPP serial interface.
The virtual access interface for each virtual circuit (VC) obtains its configuration from a virtual interface template (virtual template) when the VC is created. Before you create the ATM VC, it is recommended that you create and configure a virtual template as described in the "Preparing for Broadband Access Aggregation" module.
Once you have configured the router for PPP over ATM, the PPP subsystem starts and the router attempts to send a PPP configure request to the remote peer. If the peer does not respond, the router periodically goes into a listen state and waits for a configuration request from the peer.
The virtual access interface is associated with the VC after LCP negotiation completes. When the PPP session goes down, the virtual access interface is no longer associated with the VC and is returned to the pool of free virtual-access interfaces.
If you set a keepalive timer of the virtual template on the interface, the virtual access interface uses the PPP echo mechanism to verify the existence of the remote peer.
The following three types of PPP over ATM connections are supported:
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Autosense for ATM PVCs
The PPPoA/PPPoE autosense for ATM PVCs feature enables a router to distinguish between incoming PPP over ATM (PPPoA) and PPP over Ethernet (PPPoE) over ATM sessions and to create virtual access based on demand for both PPP types.
Note
Benefits of Autosense for ATM PVCs
Autosense for ATM PVCs provides resource allocation on demand. For each permanent virtual circuit (PVC) configured for both PPPoA and PPPoE, certain resources (including one virtual-access interface) are allocated upon configuration, regardless of the existence of a PPPoA or PPPoE session on that PVC. With the autosense for ATM PVCs, resources are allocated for PPPoA and PPPoE sessions only when a client initiates a session, thus reducing overhead on the network access server (NAS).
How to Provide Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
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Configuring IETF-Compliant MUX Encapsulated PPP over ATM
Internet Engineering Task Force (IETF)-compliant multiplexer (MUX) encapsulated PPP over ATM, also known as null encapsulation, allows you to configure PPP over ATM using a VC multiplexed encapsulation mode. This feature complies with IETF RFC 2364 entitled PPP over AAL5.
You can configure ATM PVCs for IETF-compliant MUX encapsulated PPP over ATM on either point-to-point or multipoint subinterfaces. Multiple PVCs on multipoint subinterfaces significantly increase the maximum number of PPP-over-ATM sessions running on a router. You can configure IETF-compliant MUX encapsulated PPP over ATM over a single ATM PVC or an ATM PVC range.
IETF-compliant PPP over ATM is not supported on ATM SVCs and can only be applied to PVCs.
The IETF-compliant PPP over ATM feature was designed to support installations with AppleTalk Data Stream Protocol (ADSL) circuits. For an example of using ADSL termination, see the "ADSL Termination: Example" section.
Perform this task to configure IETF-compliant MUX Encapsulated PPP over ATM.
SUMMARY STEPS
1.
2.
3.
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
4.
or
range [range-name] pvc start-vpi/start-vci end-vpi/end-vci
5.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
•
Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
interface atm slot/port.subinterface-number point-to-point
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
Example:Router(config)# interface atm 6/0.200 point-to-point
or
Router(config)# interface atm 1/0/0.4 multipoint
Specifies the ATM point-to-point or multipoint subinterface using the appropriate format of the interface atm command.1
Step 4
pvc [name] vpi/vci
or
range [range-name] pvc start-vpi/start-vci end-vpi/end-vci
Example:Router(config-subif)# pvc cisco 0/5
or
Router(config-subif)# range range1 pvc 1/200 1/299
Configures the PVC or a range of PVCs.
Step 5
encapsulation aal5mux ppp virtual-template number
Example:Router(config-subif-atm-vc)# encapsulation aal5mux ppp virtual-template 3
or
Router(config-subif-atm-range) encapsulation aal5mux ppp virtual-template 3
Configures VC multiplexed encapsulation on a PVC or PVC range.
1 To determine the correct form of the interface atm command, consult your ATM network module, port adapter, or router documentation.
Configuring IETF-Compliant LLC Encapsulated PPP over ATM
IETF-compliant LLC encapsulated PPP over ATM allows you to configure PPP over ATM with LLC encapsulation. It accommodates Frame Relay-to-ATM service interworking (Frame Relay Forum standard FRF.8). There is no equivalent VC multiplexed encapsulation mode for Frame Relay; therefore, LLC encapsulation is required for Frame Relay-to-ATM networking. This version of PPP over ATM also enables you to carry multiprotocol traffic. For example, a VC will carry both PPP and IPX traffic.
Figure 3 shows Frame Relay-to-ATM interworking.
Figure 3 Frame Relay-to-ATM Interworking
You can configure ATM PVCs for IETF-compliant LLC encapsulated PPP over ATM on either point-to-point or multipoint subinterfaces. Multiple PVCs on multipoint subinterfaces significantly increase the maximum number of PPP-over-ATM sessions running on a router.
You can also configure IETF-compliant LLC encapsulated PPP over ATM in a VC class and apply this VC class to an ATM VC, subinterface, or interface. For information about configuring a VC class, refer to the section "Configuring VC Classes" in the module "Configuring ATM."
Note
Perform this task to configure IETF-compliant LLC encapsulated PPP over ATM on a PVC or range of PVCs.
SUMMARY STEPS
1.
2.
3.
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
4.
or
range [range-name] pvc start-vpi/end-vpi start-vci/end-vci
5.
6.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
•
Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
interface atm slot/port.subinterface-number point-to-point
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
Example:Router(config)# interface atm 6/0.200 point-to-point
or
Router(config)# interface atm 1/0/0.4 multipoint
Specifies the ATM point-to-point or multipoint subinterface using the appropriate format of the interface atm command.1
Step 4
pvc [name] vpi/vci
or
range [range-name] pvc start-vpi/start-vci end-vpi/end-vci
Example:Router(config-subif)# pvc cisco 0/5
or
Router(config-subif)# range range1 pvc 1/200 1/299
Configures the PVC or a range of PVCs.
Step 5
encapsulation aal15snap
Example:Router(config-subif-atm-vc)# encapsulation aal15snap
or
Router(config-subif-atm-range)# encapsulation aal15snap
Configures LLC SNAP encapsulation on the PVC or range of PVCs.2
Step 6
protocol ppp virtual-template number
Example:Router(config-subif-atm-vc)# protocol ppp virtual-template 2
or
Router(config-subif-atm-range)# protocol ppp virtual-template 2
Configures IETF PPP over ATM LLC encapsulation on the PVC or range of PVCs.
1 To determine the correct form of the interface atm command, consult your ATM network module, port adapter, or router documentation.
2 "SNAP encapsulation" is a misnomer here, since this encapsulation configures both LLC and SNAP encapsulation on the VC. If SNAP encapsulation is not configured at a lower inheritance level, or another type of encapsulation is configured at a lower inheritance level, you will have to configure both SNAP and the protocol ppp command to ensure that PPP over ATM with LLC encapsulation is configured on your VC.
Configuring Cisco-Proprietary PPP over ATM PVCs
You can configure ATM PVCs for Cisco-proprietary PPP over ATM on either point-to-point or multipoint subinterfaces. Configuring multiple PVCs on multiple subinterfaces significantly increases the maximum number of PPP-over-ATM sessions running on a router. Remote branch offices must have Cisco-proprietary PPP over ATM configured on PPP-compatible devices interconnecting directly to Cisco's ATM Switch Interface Shelf (AXIS) equipment through a leased-line connection. The shelves provide frame forwarding encapsulation and are terminated on BPX cores prior to connecting to a Cisco 7500 series router.
Perform this task to configure Cisco-proprietary PPP over ATM on a PVC or range of PVCs.
SUMMARY STEPS
1.
2.
3.
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
4.
or
range [range-name] pvc start-vpi/start-vci end-vpi/end-vci
5.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
•
Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
interface atm slot/port.subinterface-number point-to-point
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
Example:Router(config)# interface atm 6/0.200 point-to-point
or
Router(config)# interface atm 1/0/0.4 multipoint
Specifies the ATM point-to-point or multipoint subinterface using the appropriate format of the interface atm command.1
Step 4
pvc [name] vpi/vci
or
range [range-name] pvc start-vpi/start-vci end-vpi/end-vci
Example:Router(config-subif)# pvc cisco 0/5
or
Router(config-subif)# range range1 pvc 1/200 1/299
Configures the PVC or a range of PVCs.
Step 5
encapsulation aal5ciscoppp virtual-template number
Example:Router(config-subif-atm-vc)# encapsulation aal5ciscoppp virtual-template 4
or
Router(config-subif-atm-range)# encapsulation aal5ciscoppp virtual-template 3
Configures Cisco-proprietary PPP over ATM encapsulation on a PVC or PVC range.
1 To determine the correct form of the interface atm command, consult your ATM network module, port adapter, or router documentation.
Configuring SVCs for NAPs and NSPs
When PPP over ATM is configured over an SVC rather than a PVC, an ATM SVC is established using a configured ATM address each time an end user initiates a connection to a Network Access Provider (NAP) or Network Service Provider (NSP). A PPP session is then established over the SVC. By using PPP, the NAPs and NSPs can authenticate users and provide suitable access to the various services being offered. Whereas PVCs require that services and destination addresses be predetermined, using PPP over ATM SVCs allows users to choose services and the quality of those services dynamically on the basis of the destination address.
Figure 4 shows a typical network topology for PPP over ATM SVCs terminating at an NAP.
Figure 4 PPP over ATM SVC Terminating at a Network Access Provider
Figure 5 shows a typical network topology of PPP over ATM SVCs terminating at an NSP.
Figure 5 PPP over ATM SVC Terminating at a Network Service Provider
The PPP over ATM SVCs feature works by associating each PPP session with a virtual-access interface. Each virtual-access interface is associated with an SVC. The SVCs use static maps that hold information about the encapsulation type and virtual template number. A single static map can accept multiple PPP over ATM SVC calls.
Perform this task to configure PPP over an ATM SVC.
SUMMARY STEPS
1.
2.
3.
or
interface atm number. subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
•
Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
interface atm slot/port.subinterface-number point-to-point
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
Example:Router(config)# interface atm 6/0.200 point-to-point
or
Router(config)# interface atm 1/0/0.4 multipoint
Specifies the ATM point-to-point or multipoint subinterface using the appropriate format of the interface atm command.1
Step 4
svc [name]
Example:Router(config-subif)# svc cisco
Configures the SVC.
Step 5
encapsulation aal5auto
Example:Router(config-subif-atm-vc)# encapsulation aal5auto
Specifies encapsulation auto, which allows the SVC to use either aal5snap or aal5mux encapsulation types.
Step 6
protocol ppp virtual-template number
Example:Router(config-subif-atm-vc)# protocol ppp virtual-template 6
Specifies that PPP is established over the ATM SVC using the configuration from the specified virtual template.
Step 7
max vc number
Example:Router(config-subif-atm-vc)# max vc 5
Specifies the maximum number of SVCs that can be established using the current configuration.
Step 8
max bandwidth kbps
Example:Router(config-subif-atm-vc)# max bandwidth 564
Specifies the total amount of bandwidth available to all SVCs in the current configuration.
Step 9
exit
Example:Router(config-subif-atm-vc)# exit
Exits VC configuration mode and returns to subinterface configuration mode.
Step 10
exit
Example:Router(config-subif)# exit
Exits subinterface configuration mode and returns to interface configuration mode.
Step 11
atm nsap-address nsap-address
Example:Router(config)# atm nsap-address AB.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234 .12
Sets the network service access point (NSAP) address for the ATM interface.
Step 12
exit
Example:Router(config)# exit
Exits configuration mode and returns to EXEC command mode.
Step 13
show atm svc
Example:Router# show atm svc
Displays all ATM SVCs and traffic information.
Step 14
show atm svc ppp
Example:Router# show atm svc ppp
Displays information about each SVC configured for PPP over ATM.
1 To determine the correct form of the interface atm command, consult your ATM network module, port adapter, or router documentation.
Configuring PPPoA Autosense for a Single PVC
Perform the following task to configure PPPoA/PPPoE autosense on a PVC.
SUMMARY STEPS
1.
2.
3.
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
4.
5.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
•
Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
interface atm slot/port.subinterface-number point-to-point
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
Example:Router(config)# interface atm 6/0.200 point-to-point
or
Router(config)# interface atm 1/0/0.4 multipoint
Specifies the ATM point-to-point or multipoint subinterface using the appropriate format of the interface atm command.1
Step 4
pvc [name] vpi/vci
Example:Router(config-subif)# pvc cisco 0/5
Configures the PVC.
Step 5
encapsulation aal5autoppp virtual-template number
Example:Router(config-subif-atm-vc)# encapsulation aal5ciscoppp virtual-template 1
Configures PPPoA/PPPoE autosense. Also specifies the virtual template interface to use to clone the new virtual-access interface for PPP session on this PVC.
1 To determine the correct form of the interface atm command, consult your ATM network module, port adapter, or router documentation.
Configuring PPPoA Autosense for a VC Class
Use the following procedure to configure PPPoA/PPPoE autosense on a VC class.
SUMMARY STEPS
1.
2.
3.
4.
5.
6.
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
7.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
•
Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
vc-class atm vc-class-name
Example:Router(config)# vc-class atm class3
Creates and names a map class.
Step 4
encapsulation aal5autoppp virtual-template number
Example:Router(config-vc-class)# encapsulation aal5ciscoppp virtual-template 1
Configures PPPoA/PPPoE autosense. Also specifies the virtual template interface to use to clone the new virtual-access interface for PPP session on this PVC.
Step 5
exit
Example:Router(config-vc-class)# exit
Returns to global configuration mode.
Step 6
interface atm slot/port.subinterface-number point-to-point
or
interface atm number.subinterface-number point-to-point
or
interface atm slot/port.subinterface-number multipoint
or
interface atm number.subinterface-number multipoint
Example:Router(config)# interface atm 6/0.200 point-to-point
or
Router(config)# interface atm 1/0/0.4 multipoint
Specifies the ATM point-to-point or multipoint subinterface using the appropriate format of the interface atm command.1
Step 7
class-int vc-class-name
Example:Router(config-subif)# class-int class3
Applies the VC class to all VCs on the ATM interface or subinterface.
1 To determine the correct form of the interface atm command, consult your ATM network module, port adapter, or router documentation.
Verifying PPPoA Autosense for ATM PVCs
Use the following procedure to verify PPPoA/PPPoE autosense.
SUMMARY STEPS
1.
2.
3.
4.
5.
DETAILED STEPS
Step 1
After the client at the other end of the PVC has initiated a PPPoA session, use this command to check that the PVC contains the PPPoA session.
Step 2
Use this command to:
•
•
•
Router# show callerLine User Service Activecon 0 - TTY 00:08:21BR0:1 hatteras PPP 00:00:14Vi1 hatteras PPP Bundle 00:00:13Step 3
Displays information about the virtual-access interface, link control protocol (LCP), protocol states, and interface statistics:
Router# show interface virtual access Virtual-Access3Virtual-Access3 is up, line protocol is upStep 4
Displays information about the active lines on the router.
Router# show userLine User Host(s) Idle Location * 2 vty 0 idle 00:00:00 bru-cse-058.cisco.com tty 2/01 ww Async interface 00:00:01 PPP: 12.12.12.3Step 5
Displays information about active Level 2 Forwarding (L2F) Protocol tunnel and message identifiers in a virtual private dial-up network (VPDN).
Router# show vpdnActive L2F tunnelsNAS Name Gateway Name NAS CLID Gateway CLID Statenas gateway 4 2 openL2F MIDsName NAS Name Interface MID Staterouter1@cisco.com nas As7 1 openrouter2@cisco.com nas As8 2 open
Configuration Examples for Configuring PPP over ATM
This section provides the following configuration examples:
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•
•
•
•
•
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IETF-Compliant MUX Encapsulated PPP over ATM Configuration: Examples
This section provides the following examples for configuring IETF-compliant PPP over ATM:
•
•
•
IETF-Compliant PPP over ATM with Different Traffic-Shaping Parameters: Example
PVCs with different PPP-over-ATM traffic-shaping parameters can be configured on the same subinterface. In the following example, three PVCs are configured for PPP over ATM on subinterface ATM 2/0.1. PVC 0/60 is configured with IETF-compliant PPP over ATM encapsulation. Its traffic-shaping parameter is an unspecified bit rate with peak cell rate at 500 kbps. PVC 0/70 is also configured with IETF-compliant PPP over ATM encapsulation, but its traffic-shaping parameter is nonreal-time variable bit rate, with peak cell rate at 1 Mbps, sustainable cell rate at 500 kbps, and burst cell size of 64 cells. PVC 0/80 is configured with the Cisco-proprietary PPP over ATM encapsulation. Its traffic-shaping parameter is an unspecified bit rate with peak cell rate at 700 kbps. For further information, refer to the "Configuring IETF-Compliant MUX Encapsulated PPP over ATM" section earlier in this module.
interface atm 2/0.1 multipointpvc 0/60encapsulation aal5mux ppp virtual-template 3ubr 500exitpvc 0/70encapsulation aal5mux ppp virtual-template 3vbr-nrt 1000 500 64exitpvc 0/80encapsulation aal5ciscoppp virtual-template 3ubr 700exitADSL Termination: Example
The IETF-Compliant PPP over ATM feature was designed to support installations with asymmetric digital subscriber line (ADSL) circuits. Figure 6 illustrates a topology for ADSL termination. This topology allows you to establish a PPP connection to a Cisco 7200 series router.
The example also illustrates the use of PPP tunneling using L2TP to provide VPDN services, in this case for the domain cisco.com. Thus, a user who logs in as bob2257@cisco.com is automatically tunneled to IP address 10.1.2.3. (See the module "Configuring Virtual Private Networks" in the Cisco IOS VPDN Configuration Guide for details about setting up VPDN services.)
An example of the commands that you might enter for the user_router, dsl7200, and cisco-gateway (as shown in Figure 6) are described below. For further information, refer to the "Configuring IETF-Compliant MUX Encapsulated PPP over ATM" section earlier in this module.
Figure 6 ADSL Termination
user_router Configuration
interface virtual-template 1ip address negotiatedppp chap hostname user_router@cisco.comppp chap password 0 ciscoexitinterface atm 0pvc 0/40encapsulation aal5mux ppp virtual-template 1exitexitdsl7200 Configuration
username user_router@cisco.com password 0 ciscousername dsl7200 password 0 ciscovpdn enablevpdn-group 1request dialin l2tp ip 10.2.1.1 domain cisco.cominterface virtual-template 1ppp authentication chapexitinterface atm 2/0pvc 0/40encapsulation aal5mux ppp virtual-template 1exitexitcisco-gateway Configuration
username cisco_gateway password 0 ciscousername user_router@cisco.com password 0 ciscovpdn enablevpdn-group 1accept dialin l2tp virtual-template 1 remote dsl7200interface loopback 0ip address 10.0.1.1 255.255.255.0exitinterface virtual-template 1ip unnumbered loopback 0peer default ip address pool pool-1exitip local pool pool-1 10.1.2.1 10.1.2.254Two Routers with Back-to-Back PVCs: Example
Figure 7 illustrates an ATM interface with two PPP sessions over two PVC session connections. (See the module "PPP Configuration" in the Cisco IOS Dial Technologies Configuration Guide for details on PPP configuration.) The sample commands following Figure 7 establish the back-to-back router configuration. For further information, refer to the "Configuring IETF-Compliant MUX Encapsulated PPP over ATM" section earlier in this module.
Figure 7 Two Routers with Back-to-Back PVCs
R1 Configuration
interface atm 2/0atm clock internalpvc 0/60encapsulation aal5mux ppp virtual-template 1ubr 90exitpvc 0/70encapsulation aal5mux ppp virtual-template 2vbr-nrt 90 50 1024exitinterface virtual-template 1ip address 10.0.1.1 255.255.255.0interface virtual-template 2ip address 10.0.2.1 255.255.255.0exitR2 Configuration
interface atm 2/0.1 multipointpvc 0/60encapsulation aal5mux ppp virtual-template 1ubr 90exitpvc 0/70encapsulation aal5mux ppp virtual-template 2vbr-nrt 90 50 1024exitexitinterface virtual-template 1ip address 10.0.1.2 255.255.255.0exitinterface virtual-template 2ip address 10.0.2.2 255.255.255.0Multiplexed Encapsulation Using VC Class: Example
In the following example, PVC 0/60 is configured on subinterface ATM 2/0.1 with a VC class attached to it. For details on creating and applying a VC class, see the section "Configuring VC Classes" in the module "Configuring ATM." By rule of inheritance, PVC 0/60 runs with IETF-compliant PPP over ATM encapsulation using the configuration from interface virtual-template 1. Its parameter is an unspecified bit rate with peak cell at 90 kbps.
interface atm 2/0.1pvc 0/60class-vc pvc-pppexitexitvc-class atm pvc-pppencapsulation aal5mux ppp virtual-template 1ubr 90exitIETF-Compliant LLC Encapsulated PPP over ATM Configuration: Examples
This section provides the following examples for configuring IETF-compliant LLC encapsulated PPP over ATM:
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•
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Configuring IETF-Compliant PPP over ATM LLC Encapsulation: Example
This example shows how to configure IETF PPP over ATM LLC encapsulation in the VC class called ppp-default. The VC class specifies virtual template 1 from which to spawn PPP interfaces, SNAP encapsulation (the default), and a UBR class traffic type at 256 kbps. When the VC class ppp-default is configured on interface 0.1, PVC 0/70 inherits these properties. PVC 0/80 overrides virtual template 1 in the VC class and uses virtual template 2 instead. PVC 0/90 also overrides virtual template 1 and uses virtual template 3 instead. In addition, PVC 0/90 uses a VC multiplexed encapsulation and a UBR class traffic type at 500 kbps. For further information, refer to the "IETF-Compliant LLC Encapsulated PPP over ATM Configuration: Examples" section.
interface atm 0.1 multipointclass-int ppp-default!pvc 0/70exit!pvc 0/80protocol ppp virtual-template 2exit!pvc 0/90encapsulation aal5mux ppp virtual-template 3ubr 500exitexit!vc-class atm ppp-defaultprotocol ppp virtual-template 1ubr 256exitOverriding a Virtual Template for IETF-Compliant PPP over ATM: Example
This example illustrates how to use inheritance to override a virtual template configuration for muxppp or ciscoppp encapsulation options. For PVC 5/505, since the encapsulation option at that level is ciscoppp virtual template 1, as specified in the VC class called muxppp, the protocol ppp virtual-template 2 command overrides only the virtual-template configuration. For further information, refer to the "IETF-Compliant LLC Encapsulated PPP over ATM Configuration: Examples" section.
interface atm 2/0class-int muxppp!pvc 5/505protocol ppp virtual-template 2exit!muxpppencapsulation aal5ciscoppp virtual-template 1exitDisabling IETF-Compliant PPP over ATM LLC Encapsulation on a Specific VC: Example
This example shows how to limit the configuration of a particular LLC encapsulated protocol to a particular VC. First, we see that the VC class called "ppp" is configured with IETF PPP over ATM with LLC encapsulation and virtual template 1. This VC class is then applied to ATM interface 1/0/0. By configuring SNAP encapsulation by itself on PVC 0/32, you disable IETF PPP over ATM with LLC encapsulation on this particular PVC; PVC 0/32 will only carry IP. For further information, refer to the "IETF-Compliant LLC Encapsulated PPP over ATM Configuration: Examples" section.
interface atm 1/0/0class-int pppexit!interface atm 1/0/0.100 point-to-pointdescription IP only VCip address 10.1.1.1 255.255.255.0pvc 0/32encapsulation aal5snapexitexit!vc-class atm pppencapsulation aal5snapprotocol ppp virtual-template 1exitCisco Proprietary-PPP-over-ATM: Example
The following example shows how to configure Cisco-proprietary PPP over ATM to use PPP unnumbered link and Challenge Handshake Authentication Protocol (CHAP) authentication. For further information, refer to the "Configuring Cisco-Proprietary PPP over ATM PVCs" section.
configure terminal!interface virtual-template 2encapsulation pppip unnumbered ethernet 0/0ppp authentication chap!interface atm 2/0.2 point-to-pointpvc 0/34encapsulation aal5ciscoppp virtual-template 2exitPPP over an ATM SVC Configuration: Example
In the following example, ATM interface 2/0/0 is configured to accept ATM SVC calls whose called party address is 47.00918100000000400B0A2501.0060837B4740.00. The same ATM NSAP address can be configured on other physical ATM interfaces as well. When a PPP session is established, a virtual-access interface is created and cloned with the configuration from virtual template 1. All PPP sessions established on this ATM interface will use the IP address of loopback interface 0. A maximum of 100 SVCs can be established using this configuration. SVCs established using this configuration cannot take up more than 50 Mbps in total bandwidth.
interface ATM 2/0/0svc annaencapsulation aal5autoprotocol ppp virtual-template 1max vc 100max bandwidth 50000atm nsap 47.00918100000000400B0A2501.0060837B4740.00!interface virtual-template 1ip unnumbered loopback 0!interface loopback 0ip address 10.7.1.1 255.255.255.0PPPoA/PPPoE Autosense on an ATM PVC: Example
In the following example, the NAS is configured with PPPoA/PPPoE autosense for ATM PVCs on PVC 30/33:
!! Configure PPP Autosense!interface ATM 0/0/0.33 multipointpvc 30/33encapsulation aal5autoppp Virtual-Template1!! Configure PPPoE!vpdn enablevpdn-group 1accept dialinprotocol pppoevirtual-template 1!ip cefinterface virtual-template 1ip unnumbered fastethernet 0/0/0ip route-cache cef!interface fastethernet 0/0/0ip address 10.1.1.1 255.255.255.0!! Enable precloning for virtual-template 1!virtual-template 1 pre-clone 2000PPPoA/PPPoE Autosense on a VC Class: Example
In the following example, the NAS is configured with PPPoA/PPPoE autosense on the VC class called MyClass. MyClass applies PPPoA/PPPoE autosense to all PVCs on the ATM 0/0/0.99 interface.
!! Configure PPP Autosense!vc-class ATM MyClassencapsulation aal5autoppp Virtual-Template1!interface ATM 0/0/0.99 multipointclass-int MyClassno ip directed-broadcastpvc 20/40pvc 30/33!! Configure PPPoE!vpdn enablevpdn-group 1accept dialinprotocol pppoevirtual-template 1!ip cefinterface virtual-template 1ip unnumbered fastethernet 0/0/0ip route-cache cef!interface fastethernet 0/0/0ip address 10.1.1.1 255.255.255.0!! Enable precloning for virtual-template 1!virtual-template 1 pre-clone 2000!PPPoA/PPPoE Autosense on Multiple VC Classes and
Virtual Templates: Example
Note
In the following example, PPPoA and PPPoE sessions are handled separately by two virtual templates.
ip cefvpdn enable!vpdn-group 1accept-dialinprotocol pppoevirtual-template 1pppoe limit per-mac 1pppoe limit per-vc 1!virtual-template 1 pre-clone 1500virtual-template 2 pre-clone 1000!interface ATM0/0/0.3 multipointno ip directed-broadcastclass-int pppauto!interface ATM0/0/0.9 multipointip address 10.16.40.1 255.255.0.0no ip directed-broadcast!interface Virtual-Template1ip unnumbered ATM0/0/0.9ip route-cache cefno ip directed-broadcastpeer default ip address pool pool-1ppp authentication pap!interface Virtual-Template2ip unnumbered ATM0/0/0.9ip route-cache cefno ip directed-broadcastpeer default ip address pool pool-2ppp authentication chap!interface fastethernet 0/0/0ip address 10.1.1.1 255.255.255.0!vc-class atm pppautoencapsulation aal5autoppp Virtual-Template2!
Note
Where to Go Next
If you want to identify a physical subscriber line for RADIUS communication with a RADIUS server, refer to the "Identifying a Physical Subscriber Line for RADIUS Access and Accounting" module.
Additional References
The following sections provide references related to providing protocol support for broadband access aggregation of PPP over ATM sessions.
Related Documents
Broadband access aggregation concepts
Understanding Broadband Access Aggregation
Broadband access aggregation preparation tasks
Preparing for Broadband Access Aggregation
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
Feature Information for Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
Table 5 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in Cisco IOS Release 12.1(1) or later releases appear in the table.
Not all commands may be available in your Cisco IOS software release. For details on when support for specific commands was introduced, see the command reference documents.
If you are looking for information on a feature in this technology that is not documented here, see the "Configuring Broadband Access Aggregation Features Roadmap."
Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. 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.
Note
Table 5 Feature Information for Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
PPP over ATM
12.1(1)
PPP over ATM enables a high-capacity central site router with an ATM interface to terminate multiple remote PPP connections. PPP over ATM provides security validation per user, IP address pooling, and service selection capability.
The following sections provide information about this feature:
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PPPoA/PPPoE Autosense for ATM PVCs
12.2(4)T
12.2(4)T3The PPPoA/PPPoE autosense for ATM PVCs feature enables a router to distinguish between incoming PPP over ATM (PPPoA) and PPP over Ethernet (PPPoE) over ATM sessions and to create virtual access based on demand for both PPP types.
The following sections provide information about this feature:
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