- Configuring ATM
- Multiprotocol over ATM Overview
- LAN Emulation Overview
- Configuring LAN Emulation
- Autosense of ATM PVCs and MUX SNAP Encapsulation
- MQC Policy Map on Configured VC Range ATM
- ATM OAM Ping
- OAM Segment Endpoint
- 802.1ah Support for Ethernet Infrastructure
- Define Interface Policy-Map AV Pairs AAA
- IMA Dynamic Bandwidth
- ATM Multilink PPP Support on Multiple VCs
- N:1 PVC Mapping to PWE with Nonunique VPIs
- Local Template-Based ATM PVC Provisioning
- Configuring ATM SNMP Trap and OAM Enhancements
- Configuring ATM PVC F5 OAM Recovery Traps
- Access Circuit Redundancy Support for IMA
- ATM AC VC Signaling and Provisioning
- Index
Contents
- ATM AC VC Signaling and Provisioning
- Finding Feature Information
- Prerequisites for ATM AC VC Signaling and Provisioning
- Restrictions for ATM AC VC Signaling and Provisioning
- Information About ATM AC VC Signaling and Provisioning
- How to Configure ATM AC VC Signaling and Provisioning
- Configuring ATM AC VC Signaling and Provisioning
- Configuration Examples for ATM AC VC Signaling and Provisioning
- Example Configuring ATM AC VC Signaling and Provisioning
- Example Verifying the VP States
- Example Verifying the VC States
- Additional References
- Feature Information for ATM AC VC Signaling and Provisioning
ATM AC VC Signaling and Provisioning
Bidirectional Forwarding Detection (BFD) is a generic protocol that detects faults in the bidirectional path between two forwarding engines. Virtual Circuit Connectivity Verification (VCCV), as applied to a pseudowire (PW), is a protocol that addresses the end-to-end fault detection and diagnostics for a pseudowire, for health monitoring purposes.
In the event of a fault in the local attachment circuit (AC), the ATM asynchronous feature supports keeping the virtual circuits (VC) or path provisioned on the data plane. The data plane remains continuously active so that the BFD VCCV packets are passed on to the peer within the Multiprotocol Label Switching (MPLS) core. When the interface goes down, the PVC is disabled in the line card; when the interface is up or enabled, the PVC is enabled once again.
- Finding Feature Information
- Prerequisites for ATM AC VC Signaling and Provisioning
- Restrictions for ATM AC VC Signaling and Provisioning
- Information About ATM AC VC Signaling and Provisioning
- How to Configure ATM AC VC Signaling and Provisioning
- Configuration Examples for ATM AC VC Signaling and Provisioning
- Additional References
- Feature Information for ATM AC VC Signaling and Provisioning
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 at the end of this module.
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 ATM AC VC Signaling and Provisioning
You need to configure the atm asynchronous command under the main ATM interface.
Cisco IOS Release 12.2(33)SRE and later support the ATM Attachment Circuit--VC Signaling and Provisioning feature only on Cisco 7600 series routers and the SIP-400 line card with Warlord Shared Port Adapter (SPA)(SPA-2XOC3-ATM) and Circuit Emulation over Packet (CEoP) SPAs and Black Russian SPAs (SPA-1CHOC3-CE-ATM).
Restrictions for ATM AC VC Signaling and Provisioning
Local switching is not supported.
PW redundancy is not supported.
A maximum of 2000 VCs are supported with or without OAM emulation.
Configuring the ATM asynchronous feature is only allowed under the main interface and not supported under the subinterface. The ATM interface with the ATM Asynchronous feature supports only L2transport virtual path (VP) and L2transport VC. All the other features such as bridging, VC bundle, and IP are not supported.
Any change to the ATM VC parameters results in the disconnection of the PW.
Enabling or disabling the ATM Asynchronous feature on a VC causes malfunction of ATM and BFD VCCV. Once the ATM Asynchronous feature is enabled, changing the interface configuration is not recommended.
Service Policy installation on ATM VP or L2transport VP is not supported.
Information About ATM AC VC Signaling and Provisioning
When an ATM interface is shut down (Customer Edge or Provider Edge, or the ATM link is down), all the VCs and VPs configured on the interface are removed from the driver. As a result, all types of traffic including VCCV and data traffic are blocked.
When there is a fault in the access side of the ATM network, or if the ATM link facing the Customer Edge router is down on the Provider Edge (PE) router, the ATM Attachment Circuit--VC Signaling and Provisioning feature ensures that the data plane is active on the Provider Edge (PE) routers that the BFD VCCV control packets are passed on to the Route Processor from the line card for BFD VCCV processing. The ATM VCs and VPs remain provisioned in the forwarding table entries on the Network Processor and line card. As a result, when the access side network is down, the health of the MPLS core can still be monitored and there is less programming required when the fault is removed from the access side network. Additionally, the Route Processor bundles a number of requests and sends a single message to the line cards for performing different operations on the VP or VCs that contribute to better performance under scale situations.
In addition, for the ATM Attachment Circuit--VC Signaling and Provisioning feature, the following criteria apply:
AAL5 and AAL0 encapsulation with cell packing is supported.
The Packet Switched Network is based on a transport technology such as MPLS or Layer 2 Tunnel Protocol Version 3 (L2TPv3).
BFD provides a generalized Hello protocol for fast failure detection of network resources such as when the interface is in a shut down state and link failures.
VCCV provides a control channel and manages the ingress and egress points so that connectivity verification messages can be sent.
BFD VCCV control channel mechanisms exchange connectivity packets between ingress and egress points over PW.
When the ATM interface is shut down, all the VCs and VPs configured on the interface are disconnected from the driver, resulting in blocking of all traffic including VCCV and data traffic.
How to Configure ATM AC VC Signaling and Provisioning
Configuring ATM AC VC Signaling and Provisioning
Perform this task to configure the ATM Attachment Circuit--VC Signaling and Provisioning feature.
1.
enable
2.
configure
terminal
3.
interface
atm
interface-number
/
slot
/
port
4.
atm
asynchronous
5.
atm
mcpt-timers
timer1
timer2
timer3
6.
cell-packing
maxcells
mcpt-timer
timer-number
7.
xconnect
peer-ipaddress
vc-id
encapsulation
mpls
8.
xconnect
peer-ipaddress
vc-id
pw-class
pw-class-name
9.
end
10.
show
atm
[vc| vp]
11.
show
atm
[vc| vp] detail
DETAILED STEPS
Configuration Examples for ATM AC VC Signaling and Provisioning
- Example Configuring ATM AC VC Signaling and Provisioning
- Example Verifying the VP States
- Example Verifying the VC States
Example Configuring ATM AC VC Signaling and Provisioning
This example shows the configuration on the PE router:
Router# interface ATM1/0/0 Router(config-if)# no ip address Router(config-if)# no atm enable-ilmi-trap Router(config-if)# pvc 2/210 l2transport Router(config-if)# xconnect 3.1.1.3 1010 pw-class BFD_dyn Router(config-if-xconn)# end
Example Verifying the VP States
This example shows the output of the show atm vp
command and lists the statistics for all VPs on an interface:
Router# show atm vp
Data CES Peak CES Avg/Min Burst MCR
Interface VPI SC VCs VCs Kbps Kbps Kbps Cells Kbps CDVT Status
1/1/0 29 0 0 149760 0 N/A N/A N/A N/A ACTIVE
1/1/0 40 0 0 149760 0 N/A N/A N/A N/A ACTIVE
1 90 0 0 149760 0 N/A N/A N/A N/A INACTIVE
10 25 0 0 149760 0 N/A N/A N/A N/A INACTIVE
10 30 0 0 149760 0 N/A N/A N/A N/A INACTIVE
Example Verifying the VC States
When the ATM interface is shut down, the VCs go into inactive state. This example shows the output of the show atm vc command that lists VC states:
Router# show atm vc
Codes: DN - DOWN, IN - INACTIVE
VCD / Peak Av/Min Burst
Interface Name VPI VCI Type Encaps SC Kbps Kbps Cells St
1/1/0 1 2 200 PVC AAL5 UBR 149760 UP
1/1/0 2 29 3 PVC F4-OAM UBR 149760 UP
1/1/0 3 29 4 PVC F4-OAM UBR 149760 UP
1/1/0 4 40 3 PVC F4-OAM UBR 149760 UP
1/1/0 5 40 4 PVC F4-OAM UBR 149760 UP
3/1/0 1 1 200 PVC AAL0 UBR 149760 UP
This example shows the output of the show atm vc detail command that lists the details of VC states:
Router# show atm vc detail ATM4/0/0: VCD: 1, VPI: 2, VCI: 200 :: Status: INACTIVE Async Status: SETUP_COMP, Admin Status: DISABLED, Flags: Setup ATM4/0/0: VCD: 1, VPI: 2, VCI: 200 :: Status: UP Async Status: SETUP_COMP, Admin Status: ENABLED, Flags: Enable
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
ATM commands |
Cisco IOS Asynchronous Transfer Mode Command Reference |
Standards
|
Standard |
Title |
|---|---|
|
None |
|
MIBs
|
MIB |
MIBs Link |
|---|---|
|
None |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
|
RFC |
Title |
|---|---|
|
None |
|
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 ATM AC VC Signaling and Provisioning
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 |
|---|---|---|
|
ATM Attachment Circuit--VC Signaling and Provisioning |
15.0(1)S |
The ATM Attachment Circuit--VC Signaling and Provisioning feature ensures that the data plane is active on the PE box, the BFD VCCV or control packets are passed on to the peer within the MPLS core (PE to PE MPLS cloud), and the smooth flow of data traffic. |