PVC Bundle Protection [IP to ATM Class of Service]

Document ID: 10492

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Circuit Bumping
      Implicit Bumping
      Explicit Bumping
PVC Protection
      Bundle's Protected Group
      Individually-Protected VC Bundle Member
Verify
Troubleshoot
      Troubleshooting Commands
Related Information

Introduction

ATM Permanent Virtual Circuit (PVC) bundle management allows you to configure multiple PVCs with different Quality of Service (QoS) characteristics between two end devices. You bind a PVC from the bundle to one or more precedence values. To determine which VC in the bundle is used to forward specific traffic, the ATM VC bundle management software matches precedence levels between the packet and VCs.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

7500:
- All PA-A3 versions. Requires VIP2-50, VIP4-50, and VIP4-80 or later. Only one PA-A3 per VIP2-50. Requires Cisco IOS Software Release 12.0(3)T and later.
- All PA-A6 versions. Requires VIP4 and RSP8 and later. Requires Cisco IOS Software Release 12.2(15)T, 12.3(1), and later.
7200/7200VXR:
- All PA-A3 versions. NPE200 or later. Requires Cisco IOS Software Release 12.0(3)T and later.
- All PA-A6 versions.7200VXR: NPE400, NSE-1, and NPE-G1. Requires Cisco IOS Software Release 12.2(15)T, 12.3(1), and later.
Catalyst 6500/7600:
- FlexWan and Enhanced FlexWan with PA-A3. Supported with MSFC2 in Cisco IOS Software Release 12.1(13)E13 and later.
- FlexWan and Enhanced FlexWan with PA-A6. Supported on SUP2 and SUP720 in Cisco IOS Software Release 12.2(14)SX and later.
7401ASR:
- All PA-A6 versions. Requires Cisco IOS Software Release 12.3(1) and later.
- All PA-A3 versions. Supported is all Cisco IOS Software releases.
Cisco 2600 and 3600:
- NM-1A-OC3, NM-4E1-IMA, NM-4T1-IMA, NM-8E1-IMA, and NM-8T1-IMA network modules. Requires Cisco IOS Software Release 12.0(7)T or later.
- NM-1A-T3 and NM-1A-E3 network modules. Requires Cisco IOS Software Release 12.1(2)T or later.
Cisco 12000:
- Cisco 12000 8-Port OC-3c/STM1 ATM Line Card. Cisco IOS Software Release 12.0(23)S or later.
- Cisco 12000 4 -port OC-3c/STM-1c ATM ISE Line Card. Cisco IOS Software Release 12.0(27)S or later.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to Cisco Technical Tips Conventions.

Circuit Bumping

Circuit Bumping is a PVC bundle protection method that re-assigns the traffic bound to a failed VC to a different VC. The two bumping methods are explicit bumping and implicit bumping. For more information about bumping, refer to Understanding PVC Bundle Bumping and Protection.

The setup in this diagram is used to illustrate bumping:

Two PVCs are created between Ema and Bernard. Ema and Bernard are two 7507s that use a PA-A3 in a VIP2-50 and run Cisco IOS Software Release 12.0(7)T. These two PVCs have been assigned the values 1/130 and 1/131 on both ends of the connection. 1/130 is switched to 1/130 by the ATM switch and 1/131 is switched to 1/131. The PVC 1/130 is configured as a Variable Bit Rate Non-Real Time (VBR-nrt) VC and 1/131 as an Available Bit Rate (ABR) VC. The precedence values 0 to 4 are bound to PVC 1/130 and precedence values 5 to 7 are bound to PVC 1/131.

Implicit Bumping

In case of a VC failure, implicit bumping (which is the default) diverts the traffic to a VC in charge of a lower precedence value. This output is a sample configuration for implicit bumping:

Bernard

interface ATM2/0/0.6 point-to-point
 ip address 14.0.0.1 255.0.0.0
 no ip directed-broadcast
 bundle bernard
  protocol ip 14.0.0.2 broadcast
  broadcast
  oam-bundle manage
  pvc-bundle 1/131 
   class-vc ABR
   precedence 5-7 
   bump implicit
   bump traffic
  pvc-bundle 1/130 
   vbr-nrt 100000 100000
   precedence 0-4 
   bump implicit
   bump traffic

Ema

interface ATM2/0/0.6 point-to-point
 ip address 14.0.0.2 255.0.0.0
 no ip directed-broadcast
 bundle ema
  protocol ip 14.0.0.1 broadcast
  broadcast
  oam-bundle manage
  pvc-bundle 1/131 
   class-vc ABR
   precedence 5-7 
   bump implicit
   bump traffic
  pvc-bundle 1/130 
   vbr-nrt 100000 100000
   precedence 0-4 
   bump implicit
   bump traffic

Note: If you configure no bump traffic on the PVC part of a bundle, this PVC does not accept bumped traffic.

Explicit Bumping

In case of a VC failure, you can force the traffic of a failed VC to a specific VC rather than let a stream that corresponds to an IP precedence automatically go to a VC that carries a lower IP precedence value.

Bernard

interface ATM2/0/0.6 point-to-point
 ip address 14.0.0.1 255.0.0.0
 no ip directed-broadcast
 bundle bernard
  protocol ip 14.0.0.2 broadcast
  broadcast
  oam-bundle manage
  pvc-bundle 1/131 
   class-vc ABR
   precedence 5-7 
   bump implicit
   bump traffic
  pvc-bundle 1/130 
   vbr-nrt 100000 100000
   precedence 0-4 
   bump explicit 5
   bump traffic

Ema

interface ATM2/0/0.6 point-to-point
 ip address 14.0.0.2 255.0.0.0
 no ip directed-broadcast
 bundle ema
  protocol ip 14.0.0.1 broadcast
  broadcast
  oam-bundle manage
  pvc-bundle 1/131 
   class-vc ABR
   precedence 5-7 
   bump implicit
   bump traffic
  pvc-bundle 1/130 
   random-detect attach testWRED
   vbr-nrt 100000 100000
   precedence 0-4 
   bump explicit 5
   bump traffic

In the previous configuration, the PVC 1/130 that is in charge of IP precedence from 0 to 4 is bumped to the PVC in charge of IP precedence equal to 5. In this case, traffic from PVC 1/130 is bumped to PVC 1/131 in case of a failure.

Note: If you configure no bump traffic on the PVC part of a bundle, this PVC does not accept bumped traffic.

PVC Protection

The second bundle protection method is called PVC protection. With this method, a router brings down the PVC when a VC member of a bundle goes down.

These are the two methods of PVC protection:

Bundle's protected group.
Individually-protected VC bundle member.

For more information about PVC protection, refer to Understanding PVC Bundle Bumping and Protection.

The setup in this diagram is used to illustrate PVC protection:

Three PVCs are created between Ema and Bernard. Ema and Bernard are two 7507s that use a PA-A3 in a VIP2-50 and run Cisco IOS Software Release 12.0(7)T. These three PVCs are assigned the values 1/129, 1/130, and 1/131 on both ends of the connection. 1/129 is switched to 1/129 by the ATM switch, 1/130 is switched to 1/130, and 1/131 to 1/131.

The PVC 1/129 is a simple Unspecified Bit Rate (UBR) PVC, 1/130 is configured as a VBR-nrt VC, and 1/131 as an ABR VC. The precedence values 1 to 4 are bound to PVC 1/130, precedence values 5 to 7 to the PVC 1/131, and precedence 0 to 1/129.

Bundle's Protected Group

This method assigns a VC into a protected group. If all VCs which are part of a protected group go down, the entire bundle goes down.

Bernard shows the configuration lines necessary to enable this protection method. A similar configuration exists on Ema.

In this case, PVC 1/130 and PVC 1/131 are members of one protected group:

Bernard

interface ATM2/0/0.6 point-to-point 
  ip address 14.0.0.1 255.0.0.0 
  no ip directed-broadcast 
  bundle bernard 
   protocol ip 14.0.0.2 broadcast 
   broadcast 
   oam-bundle manage 
   pvc-bundle 1/131  
    class-vc ABR 
    random-detect attach testWRED 
    precedence 5-7  
    bump implicit 
    bump traffic 
   protect group 
   pvc-bundle 1/130  
    random-detect attach testWRED 
    vbr-nrt 100000 100000 
    precedence 1-4 
    bump implicit 
    bump traffic 
    protect group 
   pvc-bundle 1/129  
    random-detect attach testWRED 
    precedence other

Ema

interface ATM2/0/0.6 point-to-point 
 ip address 14.0.0.2 255.0.0.0 
  no ip directed-broadcast 
  bundle ema 
   protocol ip 14.0.0.1 broadcast 
   broadcast 
   oam-bundle manage 
   pvc-bundle 1/131  
    class-vc ABR 
    random-detect attach testWRED 
    precedence 5-7 
    bump implicit 
    bump traffic 
    protect group 
   pvc-bundle 1/130  
    random-detect attach testWRED 
   vbr-nrt 100000 100000 
    precedence 1-4 
    bump implicit 
    bump traffic 
    protect group 
   pvc-bundle 1/129  
    random-detect attach testWRED 
    precedence other

In this configuration, PVC 1/130 and 1/131 are part of the same group. If one of these goes down, the PVC goes down.

Individually-Protected VC Bundle Member

If an individually-protected VC goes down, the whole bundle is brought down. Bernard shows the configuration lines necessary to enable this protection method. A similar configuration exists on Ema.

In this case, PVC 1/131 is the individually-protected VC:

Bernard

interface ATM2/0/0.6 point-to-point
  ip address 14.0.0.1 255.0.0.0
  no ip directed-broadcast
  bundle bernard
   protocol ip 14.0.0.2 broadcast
   broadcast
   oam-bundle manage
   pvc-bundle 1/131 
    class-vc ABR
    random-detect attach testWRED
    precedence 5-7 
    bump implicit
    bump traffic
    protect vc
  pvc-bundle 1/130 
   random-detect attach testWRED
   vbr-nrt 100000 100000
   precedence 1-4
  pvc-bundle 1/129  
    random-detect attach testWRED 
    precedence other

Ema

interface ATM2/0/0.6 point-to-point
   ip address 14.0.0.2 255.0.0.0
   no ip directed-broadcast
   bundle ema
    protocol ip 14.0.0.1 broadcast
    broadcast
    oam-bundle manage
    pvc-bundle 1/131 
     class-vc ABR
     random-detect attach testWRED
     precedence 5-7 
     bump implicit
     bump traffic
     protect vc
   pvc-bundle 1/130 
    random-detect attach testWRED
    vbr-nrt 100000 100000
    precedence 1-4
   pvc-bundle 1/129  
    random-detect attach testWRED 
    precedence other

Verify

This section provides information you can use to confirm your configuration is working properly.

Certain show commands are supported by the Output Interpreter Tool (registered customers only) , which allows you to view an analysis of show command output.

show atm bundle [bundle name]

Bernard#show atm bundle

bernard on ATM2/0/0.6: UP

                       Config    Current   Bumping  PG/ Peak Avg/Min Burst
VC Name      VPI/ VCI  Prec/Exp  Prec/Exp  PrecExp/ PV  Kbps   kbps  Cells Sts
                                           Accept

1              1/131   7-5       7-5       - / Yes  PV 155000  50000        UP
2              1/130   4-1       4-1       - / Yes  -  100000 100000   94   UP
3*             1/129   0         0         - / No   -  149760               UP

show atm pvc vpi/vci

Bernard#show atm pvc 1/130
ATM2/0/0.6: VCD: 2, VPI: 1, VCI: 130
VBR-NRT, PeakRate: 100000 (235850 cps), Average Rate: 100000 (235850 cps)
Burst Cells: 94
AAL5-LLC/SNAP, etype:0x0, Flags: 0x20, VCmode: 0x0, Encapsize: 12
OAM frequency: 10 second(s), OAM retry frequency: 1 second(s)
OAM up retry count: 3, OAM down retry count: 5
OAM Loopback status: OAM Received
OAM VC Status: Verified
ILMI VC status: Not Managed
VC is managed by OAM.
InARP frequency: 15 minutes(s)
Transmit priority 4
InPkts: 0, OutPkts: 0, InBytes: 0, OutBytes: 0
InCells: 0, OutCells: 0
InPRoc: 0, OutPRoc: 0
InFast: 0, OutFast: 0, InAS: 0, OutAS: 0
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0, CPIErrors: 0
Out CLP=1 Pkts: 0, Cells: 0
OAM cells received: 1399
F5 InEndloop: 1399, F5 InSegloop: 0, F5 InAIS: 0, F5 InRDI: 0
F4 InEndloop: 0, F4 InSegloop: 0, F4 InAIS: 0, F4 InRDI: 0
OAM cells sent: 1428
F5 OutEndloop: 1428, F5 OutSegloop: 0, F5 OutRDI: 0
F4 OutEndloop: 0, F4 OutSegloop: 0, F4 OutRDI: 0
OAM cell drops: 0
Status: UP
VC 1/130 doesn't exist on 1 of 2 ATM interface(s)


Bernard#show atm pvc 1/131
ATM2/0/0.6: VCD: 1, VPI: 1, VCI: 131
ABR, PeakRate: 155000 (365567 cps), Minimum Rate: 50000 (117925 cps)
Initial Rate: 155000 (365567 cps), Current Rate: 0 (0 cps)
RIF: 16, RDF: 16
FRM cells received: 0, BRM cells received: 0
RM cells sent: 0
AAL5-LLC/SNAP, etype:0x0, Flags: 0x10820, VCmode: 0x0, Encapsize: 12
OAM frequency: 10 second(s), OAM retry frequency: 1 second(s)
OAM up retry count: 3, OAM down retry count: 5
OAM Loopback status: OAM Received
OAM VC Status: Verified
ILMI VC status: Not Managed
VC is managed by OAM.
InARP frequency: 15 minutes(s)
Transmit priority 5
InPkts: 0, OutPkts: 0, InBytes: 0, OutBytes: 0
InCells: 0, OutCells: 0
InPRoc: 0, OutPRoc: 0
InFast: 0, OutFast: 0, InAS: 0, OutAS: 0
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0, CPIErrors: 0
Out CLP=1 Pkts: 0, Cells: 0
OAM cells received: 1413
F5 InEndloop: 1413, F5 InSegloop: 0, F5 InAIS: 0, F5 InRDI: 0
F4 InEndloop: 0, F4 InSegloop: 0, F4 InAIS: 0, F4 InRDI: 0
OAM cells sent: 1441
F5 OutEndloop: 1441, F5 OutSegloop: 0, F5 OutRDI: 0
F4 OutEndloop: 0, F4 OutSegloop: 0, F4 OutRDI: 0
OAM cell drops: 0
Status: UP
VC 1/131 doesn't exist on 1 of 2 ATM interface(s)

Troubleshoot

This section provides information you can use to troubleshoot your configuration.

Troubleshooting Commands

Certain show commands are supported by the Output Interpreter Tool (registered customers only) , which allows you to view an analysis of show command output.

Note: Before issuing debug commands, refer to Important Information on Debug Commands.

debug atm bundle events and debug atm bundle errors

Bernard#debug atm bundle events
ATM VC Bundle Events debugging is on
Bernard#debug atm bundle errors
ATM VC Bundle Errors debugging is on

1d17h: BUNDLE EVENT(bernard): b_update_vc for   1/131   with bstate 1, vc_state3
1d17h: BUNDLE EVENT(bernard): bundle active precedence erased
1d17h: BUNDLE EVENT(bernard):bundle down
	
Bernard#show atm bundle

bernard on ATM2/0/0.6: DOWN, PV down

                       Config    Current   Bumping  PG/ Peak Avg/Min Burst
VC Name      VPI/ VCI  Prec/Exp  Prec/Exp  PrecExp/ PV  Kbps   kbps  Cells Sts
                                           Accept

1              1/131   7-5                 - / Yes  PV 155000  50000      DOWN
2              1/130   4-1                 - / Yes  -  100000 100000   94   UP
3*             1/129   0                   - / No   -  149760               UP

Bernard#show atm pvc 1/131
ATM2/0/0.6: VCD: 1, VPI: 1, VCI: 131
ABR, PeakRate: 155000 (365567 cps), Minimum Rate: 50000 (117925 cps)
Initial Rate: 155000 (365567 cps), Current Rate: 0 (0 cps)
RIF: 16, RDF: 16
FRM cells received: 0, BRM cells received: 0
RM cells sent: 0
AAL5-LLC/SNAP, etype:0x0, Flags: 0x10820, VCmode: 0x0, Encapsize: 12
OAM frequency: 10 second(s), OAM retry frequency: 1 second(s)
OAM up retry count: 3, OAM down retry count: 5
OAM Loopback status: OAM Sent
OAM VC Status: Not Verified
ILMI VC status: Not Managed
VC is managed by OAM.
InARP frequency: 15 minutes(s)
Transmit priority 5
InPkts: 0, OutPkts: 0, InBytes: 0, OutBytes: 0
InCells: 0, OutCells: 0
InPRoc: 0, OutPRoc: 0
InFast: 0, OutFast: 0, InAS: 0, OutAS: 0
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0, LengthViolation: 0, CPIErrors: 0
Out CLP=1 Pkts: 0, Cells: 0
OAM cells received: 1450
F5 InEndloop: 1450, F5 InSegloop: 0, F5 InAIS: 0, F5 InRDI: 0
F4 InEndloop: 0, F4 InSegloop: 0, F4 InAIS: 0, F4 InRDI: 0
OAM cells sent: 1508
F5 OutEndloop: 1508, F5 OutSegloop: 0, F5 OutRDI: 0
F4 OutEndloop: 0, F4 OutSegloop: 0, F4 OutRDI: 0
OAM cell drops: 0
Status: DOWN, State: NOT_VERIFIED

VC 1/131 doesn't exist on 1 of 2 ATM interface(s)

Related Information

Understanding PVC Bundle Bumping and Protection
ATM Technology Support Pages
ATM Acronyms
Technical Support - Cisco Systems

Updated: Nov 15, 2007

Document ID: 10492

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