mpls switch-l2vc between encapsulation bit-error-detection

Function

The mpls switch-l2vc between encapsulation bit-error-detection command enables bit-error-triggered PW switching on an SPE of an MS-PW.

The undo mpls switch-l2vc between encapsulation bit-error-detection command disables bit-error-triggered PW switching on an SPE of an MS-PW.

By default, bit-error-triggered PW switching is disabled on an SPE of an MS-PW.

Format

mpls switch-l2vc ip-address vc-id between ip-address vc-id encapsulation { atm-1to1-vcc | atm-1to1-vpc | atm-aal5-pdu | atm-aal5-sdu | atm-nto1-vcc | atm-nto1-vpc | atm-trans-cell | cesopsn-basic | ethernet | fr | ip-interworking | ip-layer2 | satop-e1 | satop-e3 | satop-t1 | vlan | cep } bit-error-detection

undo mpls switch-l2vc ip-address vc-id between ip-address vc-id encapsulation { atm-1to1-vcc | atm-1to1-vpc | atm-aal5-pdu | atm-aal5-sdu | atm-nto1-vcc | atm-nto1-vpc | atm-trans-cell | cesopsn-basic | ethernet | fr | ip-interworking | ip-layer2 | satop-e1 | satop-e3 | satop-t1 | vlan | cep } bit-error-detection

Parameters

Parameter	Description	Value
ip-address	Specifies an LSR ID of the remote device on the PW.	The value is in dotted decimal notation.
vc-id	Specifies the ID of a L2VC.	The value is a decimal integer ranging from 1 to 4294967295.
between	Specifies the PW used with the current PW to form an MS-PW.	-
encapsulation	Indicates the PW encapsulation type.	-
atm-1to1-vcc	One PW carries the AAL5 SDUs of one PVC.	-
atm-1to1-vpc	One PW carries the AAL5 SDUs of one PVC.	-
atm-aal5-pdu	One PW carries the AAL5 SDUs of one PVC.	-
atm-aal5-sdu	One PW carries the AAL5 SDUs of one PVC.	-
atm-nto1-vcc	One PW carries the ATM cells of multiple PVCs.	-
atm-nto1-vpc	ATM cells are transmitted over PWE3 VCs.	-
atm-trans-cell	ATM cells are transmitted over PWE3 VCs.	-
cesopsn-basic	Specifies the PW encapsulation type as cesopsn-basic.	-
ethernet	This encapsulation type is used when Ethernet packets do not carry VLAN information.	-
fr	FR provides protocol standards for the data link layer and physical layer.	-
ip-interworking	Enables static PW interworking when devices in the interworking are all provided by Huawei.	-
ip-layer2	Enables IP interworking for an LDP PW between a Huawei device and a non-Huawei device. ip-layer2 is required for IP interworking between a Huawei device and a non-Huawei device.	-
satop-e1	SAToP is insensitive to the E1 frame structure and encapsulates a whole E1 frame into a PW packet.	-
satop-e3	SAToP is insensitive to the E3 frame structure and encapsulates a whole E3 frame into a PW packet.	-
satop-t1	SAToP is insensitive to the T1 frame structure and encapsulates a whole T1 frame into a PW packet.	-
vlan	This encapsulation type is used when Ethernet packets carry VLAN information.	-
cep	This encapsulation type is used for CEP services.	-
bit-error-detection	Specifies to use CRC to detect bit errors.	-

Views

System view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2vpn	write

Usage Guidelines

Usage Scenario

In a PW redundancy scenario, if the endpoint PEs of a PW are in different ASs, you must configure the PW as an MS-PW. BFD for PW and BFD for LSP, two commonly deployed detection mechanisms in PW redundancy scenarios, can trigger the active/standby switchover of PWs only after detecting the loss of three consecutive BFD packets.

To resolve this problem, you can configure bit-error-triggered protection switching for the MS-PW. Bit-error-triggered PW switching uses CRC to check the bit error rate and works with the TE hot standby LSP or PW to protect services transmitted over a PW, ensuring end-to-end service quality of a PW.

Prerequisites

The mpls l2vpn command has been run to enable MPLS L2VPN.

Configuration Impact

After you enable bit-error-triggered PW switching on the SPEs and endpoint PEs, the primary and secondary PWs respond to bit error events and perform an active/standby switchover as needed. In a scenario in which both the primary and secondary PWs are normal:

If the primary PW does not encounter a bit error event, the primary PW forwards traffic.
If the primary PW encounters a bit error event but the secondary PW does not, the secondary PW takes over traffic from the primary PW.
If the primary and secondary PWs both encounter a bit error event, the primary PW forwards traffic.

Precautions

The mpls switch-l2vc bit-error-detection command applies to only dynamic LDP MS-PWs.

Example

# Enable bit-error-triggered PW switching on an SPE of a dynamic LDP MS-PW.

<HUAWEI> system-view
[*HUAWEI] mpls
[*HUAWEI-mpls] quit
[*HUAWEI] mpls l2vpn
[*HUAWEI-l2vpn] quit
[~HUAWEI] mpls switch-l2vc 1.1.1.9 100 between 3.3.3.9 100 encapsulation vlan
[*HUAWEI] mpls switch-l2vc 1.1.1.9 100 between 3.3.3.9 100 encapsulation vlan bit-error-detection