- Read Me First
- Preparing for Broadband Access Aggregation
- Providing Protocol Support for Broadband Access Aggregation of PPPoE Sessions
- PPP for IPv6
- DHCP for IPv6 Broadband
- Providing Protocol Support for Broadband Access Aggregation of PPP over ATM Sessions
- Providing Connectivity Using ATM Routed Bridge Encapsulation over PVCs
- PPPoE Circuit-Id Tag Processing
- Configuring PPP over Ethernet Session Limit Support
- PPPoE Session Limit Local Override
- PPPoE QinQ Support
- PPP-Max-Payload and IWF PPPoE Tag Support
- PPPoE Session Limiting on Inner QinQ VLAN
- PPPoE Agent Remote-ID and DSL Line Characteristics Enhancement
- Enabling PPPoE Relay Discovery and Service Selection Functionality
- Configuring Cisco Subscriber Service Switch Policies
- AAA Improvements for Broadband IPv6
- Per Session Queueing and Shaping for PPPoEoVLAN Using RADIUS
- 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- PPP over Ethernet Client
- PPPoE Smart Server Selection
- Monitoring PPPoE Sessions with SNMP
- PPPoE on ATM
- PPPoE on Ethernet
- PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support
- ADSL Support in IPv6
- Broadband IPv6 Counter Support at LNS
- PPP IP Unique Address and Prefix Detection
- PPP IPv4 Address Conservation in Dual Stack Environments
- TR-069 Agent
- Broadband High Availability Stateful Switchover
- Broadband High Availability In-Service Software Upgrade
- Controlling Subscriber Bandwidth
- PPPoE Service Selection
- Disabling AC-name and AC-cookie Tags from PPPoE PADS
PPPoE on ATM
This feature module describes the PPP over Ethernet (PPPoE) on ATM feature. The PPPoE on ATM feature provides the ability to connect a network of hosts over a simple bridging-access device to a remote access concentrator.
- Finding Feature Information
- Prerequisites for PPPoE on ATM
- Restrictions for PPPoE on ATM
- Information About PPPoE on ATM
- How to Configure PPPoE on ATM
- Configuration Examples for PPPoE on ATM
- Where to Go Next
- Additional References
- Feature Information for PPPoE on ATM
- Glossary
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for PPPoE on ATM
Before you can configure PPPoE on ATM, you need to specify a virtual template for the PPPoE sessions using the virtual-template command.
Restrictions for PPPoE on ATM
PPPoE is not supported on Frame Relay.
PPPoE over ATM AAl5Mux is not supported on ASR series 1000 routers. For more information, refer to the PPPoEoA over ATM AAL5Mux feature: http://www.cisco.com/en/US/docs/ios/bbdsl/configuration/guide/bba_pppoeoa_aal5mux.html
PPPoE is not supported on any other LAN interfaces such as FDDI and Token Ring.
Fast switching is supported. PPPoE over RFC 1483 fibswitching is supported for IP. All other protocols are switched over process switching.
Bridging is supported on the ATM permanent virtual connections (PVCs) running PPPoE.
PPPoE is supported on ATM PVCs compliant with RFC 1483 only.
Only dial-in mode is supported. Dial-out mode will not be supported.
Information About PPPoE on ATM
The PPPoE on ATM feature provides the ability to connect a network of hosts over a simple bridging-access device to a remote access concentrator. With this model, each host utilizes its own PPPoE stack and the user is presented with a familiar user interface. Access control, billing and type of service can be done on a per-user, rather than a per-site, basis. Before a point-to-point connection over Ethernet can be provided, each PPP session must learn the Ethernet address of the remote peer and establish a unique session identifier. A unique session identifier is provided by the PPPoE Discovery Stage protocol.
The figure below shows a sample network topology using PPPoE on ATM.
PPPoE Stage Protocols
PPPoE has two distinct stage protocols. The stage protocols are listed and summarized in the table below.
|
Stage Protocols |
Description |
|---|---|
|
Discovery Stage protocol |
Remains stateless until a PPPoE session is established. Once the PPPoE session is established, both the host and the access concentrator must allocate the resources for a PPP virtual access interface. |
|
PPP Session Stage protocol |
Once the PPPoE session is established, sends PPPoE data as in any other PPP encapsulation. |
There are four steps to the Discovery Stage:
Host broadcasts a PPPoE Active Discovery Initiation (PADI) packet.
When the access concentrator receives a PADI that it can serve, it replies by sending a PPPoE Active Discovery Offer (PADO) packet to the host.
Because the PADI was broadcast, the host may receive more than one PADO packet. The host looks through the PADO packets it receives and chooses one. The choice can be based on the AC name or the services offered. The host then sends a single PPPoE Active Discovery Request (PADR) packet to the access concentrator that it has chosen.
When the access concentrator receives a PADR packet, it prepares to begin a PPP session. It generates a unique SESSION_ID for the PPPoE session and replies to the host with a PPPoE Active Discovery Session-confirmation (PADS) packet.
When a host wishes to initiate a PPPoE session, it must first perform discovery to identify the Ethernet MAC address of the peer and establish a PPPOE SESSION_ID. Although PPP defines a peer-to-peer relationship, discovery is inherently a client/server relationship. In the discovery process, a host (the client) discovers an access concentrator (the server). Based on the network topology, there may be more than one access concentrator that the host can communicate with. The Discovery Stage allows the host to discover all access concentrators and then select one. When discovery is completed, both the host and the selected access concentrator have the information they will use to build their point-to-point connection over Ethernet.
Benefits of PPPoE on ATM
The PPPoE on ATM feature provides service-provider digital subscriber line (DSL) support. As service providers begin DSL deployments, two of their most significant goals are to ease and facilitate consumer end adoption and to preserve as much of the dialup model as possible. PPPoE serves to advance both of these goals by leveraging ethernet scale curves and embedded base (such as ATM NICs) and by preserving the point-to-point session used by internet service providers (ISPs) in today’s dialup model.
Using a PPPoE client (available from RouterWare), a PPP session can be initiated on an Ethernet connected client through a standard ADSL modem. The session is transported over the ATM DSL link via RFC 1483 Ethernet bridged frames and can terminate either in the LAN emulation client (LEC) central office or the ISP point of presence (POP). The termination device can be an aggregation box such as the Cisco 6400 or a router such as the Cisco 7200 series platforms.
As customers deploy asymmetric DSL (ADSL), they will encounter the need to enable users to access remote-access concentrators via simple bridges connecting Ethernet and ATM networks.
How to Configure PPPoE on ATM
- Enabling PPP over ATM
- Creating and Configuring a Virtual Template
- Specifying an ATM Subinterface
- Creating an ATM PVC
- Enabling PPPoE on an ATM PVC
Enabling PPP over ATM
After you configure the Cisco router or access server for Ethernet encapsulation, you must configure the physical interface with the PVC and apply a virtual template with PPP encapsulation to the PVC that it applies to. To configure the physical interface that will carry the PPPoE session and link it to the appropriate virtual template interface, use the following commands:
 Note | You can use the virtual-template, sessions per-vc, and sessions per-mac commands in any order. |
- protocol pppoe group {group-name | global}
- or
- encapsulation aal5snap
1.
enable
2.
configure
terminal
3.
bba-group
pppoe
{group-name | global}
4.
virtual-template
template-number
5.
sessions
per-vc
limit
per-vc-limit
[threshold threshold-value]
6.
sessions
per-mac
limit
per-mac-limit
7.
exit
8.
interface
atm
slot
/
subslot
/
port
[.subinterface][point-to-point | multipoint]
9.
ip
address
ip-address
mask
[secondary]
10.
range
[range-name] pvc start-vpi / start-vci end-vpi / end-vci
11.
dbs
enable
[aggregated | maximum]
12.
Do one of the following:
13.
create
on-demand
14.
end
DETAILED STEPS
Creating and Configuring a Virtual Template
Specifying an ATM Subinterface
After you create a virtual template for PPPoE on ATM, specify a multipoint or point-to-point subinterface per PVC connection. To specify an ATM multipoint subinterface, use the following commands:
1.
enable
2.
configure
terminal
3.
interface
atm
slot
/
subslot
/
port
.subinterface
] [multipoint| point-to-point]
4.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| 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
/
subslot
/
port
.subinterface
] [multipoint| point-to-point] Example: Router# interface atm 6/0.110 multipoint |
Configures the ATM interface and enters subinterface configuration mode.
|
| Step 4 |
end
Example: Router(config-subif)# end |
(Optional) Exits the subinterface configuration mode and returns to privileged EXEC mode. |
Creating an ATM PVC
Enabling PPPoE on an ATM PVC
To enable PPPoE on an ATM PVC, use the following commands:
1.
enable
2.
configure
terminal
3.
interface
atm
slot
/
subslot
/
port
[.subinterface]
[multipoint |
point-to-point]
4.
pvc
[name]
vpi / vci
5.
pppoe
max-sessions
number-of-sessions
[threshold-sessions number-of-sessions]
6.
protocol
pppoe
7.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| 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
/
subslot
/
port
[.subinterface]
[multipoint |
point-to-point]
Example: Router(config)# interface atm 0/0/0.3 multipoint |
Configures the ATM interface and enters the subinterface configuration mode. |
| Step 4 |
pvc
[name]
vpi / vci Example: Router(config-subif)# pvc 5/120 |
Creates an ATM PVC and enters ATM VC configuration mode. |
| Step 5 |
pppoe
max-sessions
number-of-sessions
[threshold-sessions number-of-sessions]
Example: Router(config-if-atm-vc)# pppoe max-sessions 5 threshold-sessions 3 |
Sets the maximum number of PPPoE sessions that will be permitted on an ATM PVC, PVC range, VC class, or VLAN, and sets the PPPoE session-count threshold at which an SNMP trap will be generated. |
| Step 6 |
protocol
pppoe
Example: Router(config-if-atm-vc)# protocol pppoe |
Enables PPPoE sessions to be established on ATM PVCs. |
| Step 7 |
end
Example: Router(config-if-atm-vc)# end |
(Optional) Exits the ATM VC configuration mode and returns to privileged EXEC mode. |
Configuration Examples for PPPoE on ATM
PPPoE on ATM Example
The following example configures PPPoE on ATM to accept dial-in PPPoE sessions. The virtual access interface for the PPP session is cloned form virtual template interface 1. On subinterface ATM 2/0.1, ATM PVC with VPI 0 and VCI 60 is configured with Logical Link Control (LLC)/Subnetwork Access Protocol (SNAP) encapsulation and is configured to run PPPoE.
bba-group pppoe pppoe-group virtual-template 1 sessions per-vc limit 1 sessions per-mac limit 4000 interface atm 2/0.1 multipoint ip address 192.0.10.2 255.255.255.0 secondary range pvc 1/100 1/202 pvc 0/60 dbs enable encapsulation aal5snap protocol pppoe group two create on-demand interface virtual-template 1 ip addr 10.0.1.2 255.255.255.0 mtu 1492
Where to Go Next
If you want to enable PPP authentication on the virtual template using the ppp authentication chap command, refer to the "Configuring Virtual Template Interfaces" chapter in the Cisco IOS Dial Solutions Configuration Guide .
If you want to configure an authentication, authorization, and accounting (AAA) server, refer to the "Configuring per-User Configuration" chapter in the Cisco IOS Dial Solutions Configuration Guide .
Additional References
The following sections provide references related to the PPPoE on ATM feature.
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
Broadband and DSL commands |
Cisco IOS Broadband Access Aggregation and DSL Command Reference |
|
Enabling PPP authentication on the virtual template |
Configuring Virtual Template Interfaces |
|
Configuring an AAA server |
Configuring per-User Configuration |
|
Configuring Broadband and DSL |
Cisco IOS XE Broadband Access Aggregation and DSL Configuration Guide |
Standards
|
Standard |
Title |
|---|---|
|
None |
-- |
|
|
|
MIBs
|
MIB |
MIBs Link |
|---|---|
|
|
To locate and download MIBs for selected platforms, Cisco IOS XE software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
|
RFC |
Title |
|---|---|
|
RFC 1483 |
Multiprotocol Encapsulation over ATM Adaptation Layer 5 |
|
RFC 2364 |
PPP over AAL5 |
|
RFC 2516 |
A Method for Transmitting PPP over Ethernet (PPPoE) |
Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
Feature Information for PPPoE on ATM
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.|
Feature Name |
Releases |
Feature Information |
|---|---|---|
|
PPPoE on ATM |
Cisco IOS XE Release 2.5 |
This feature was introduced on Cisco ASR 1000 Series Aggregation Services Routers. This feature module describes the PPP over Ethernet (PPPoE) on ATM feature. The PPPoE on ATM feature provides the ability to connect a network of hosts over a simple bridging-access device to a remote access concentrator. The following commands were introduced or modified: bba-group, protocol (VPDN), virtual-template. |
Glossary
AAL5 --ATM Adaptation Layer 5
ADSL --Asymmetric Digital Subscriber Line
ATM --Asynchronous Transfer Mode
CPCS --Common Part of Convergence Sublayer
CPI --Common Part Indicator
CRC --Cyclic Redundancy Check
DSLAM --Digital Subscriber Line Access Multiplexer
FCS --Frame Check Sequence
IETF --Internet Engineering Task Force
ID -Identifier
IP --Internet Protocol
L2TP --Layer two Tunneling Protocol
LAN --Local Area Network
LLC --Logical Link Control
MAC --Media Access Control
PDU --Protocol Data Unit
PPP --Point to Point Protocol
PPPoE --Point to Point Protocol over Ethernet
PVC --Permanent Virtual Connection
VPDN --Virtual Private Dialup Network
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