Example for Configuring Frame LM for a Bidirectional LSP

This section provides an example for configuring frame loss measurement (LM) for a bidirectional label switched path (LSP).

Networking Requirements

As a connection-oriented packet switching technology, Multiprotocol Label Switching Transport Profile (MPLS-TP) is designed to convert a circuit switched transport network to a packet switched transport network. The purpose is to increase the transmission rate on the transport network.

Link reliability must be ensured when MPLS-TP is used. Although users do not sense a change in voice quality if the frame loss ratio on voice links is lower than 10%, for example, the frame loss ratio higher than 20% causes obvious reductions of voice quality.

The frame loss ratio is the ratio of lost frames to the frames sent during a specified period in percentage terms. The number of lost frames is the difference between the number of frames sent by the ingress and the number of frames received by the egress on a point-to-point LSP.

Frame LM can be used to collect frame loss statistics and evaluate link performance. LM is a performance monitoring function provided by MPLS-TP and is classified as single-ended frame LM or dual-ended frame LM.

The configuration of dual-ended frame LM is used as an example in this section. Regardless of single-ended or dual-ended, DM configurations on PEs are the same except the statistics display configurations.

On the network shown in Figure 1, a bidirectional LSP is established to connect label switching routers (LSRs) A, B, and C. The following deployment is made to ensure the connectivity between LSRA and LSRC:

LSRA and LSRC serve as MEPs.
LSRB serves as a MIP.

Figure 1 Bidirectional LSP

Interfaces 1 through 2 in this example are GE 0/1/0 and GE 0/1/8, respectively.

**Table 1** Interfaces and IP addresses
Device	Interface	IP Address
LSRA	Loopback1	1.1.1.1/32
LSRA	GigabitEthernet0/1/0	2.1.1.1/24
LSRB	Loopback1	2.2.2.2/32
	GigabitEthernet0/1/0	2.1.1.2/24
	GigabitEthernet0/1/8	3.2.1.1/24
LSRC	Loopback1	3.3.3.3/32
LSRC	GigabitEthernet0/1/8	3.2.1.2/24

Configuration Roadmap

The configuration roadmap is as follows:

Create a maintenance entity (ME) instance and bind it to a bidirectional LSP.
Enable continuity check (CC) and connectivity verification (CV) on the MEP and its remote MEP (RMEP).
Configure an alarm threshold for lost frames.
Enable dual-ended frame LM.

Data Preparation

To complete the configuration, you need the following data:

MEG name
Name of the tunnel interface to which an ME instance is bound
Alarm threshold for lost frames

Procedure

Configure a bidirectional LSP.
For configuration details, see "Example for Configuring a Static Bidirectional Co-routed CR-LSP" in HUAWEI NetEngine 8000 F SeriesRouter Configuration Guide - MPLS or "Configuration Files" in this section.

Create an ME instance and bind it to the bidirectional LSP.

# Create an ME instance named test on LSRA and bind it to Tunnel 10.

[~LSRA] mpls-tp meg test
[~LSRA-mpls-tp-meg-test] me te interface Tunnel 10 mep-id 1 remote-mep-id 2
[*LSRA-mpls-tp-meg-test] commit

# Create an ME instance named test on LSRC and bind it to Tunnel 20.

[~LSRC] mpls-tp meg test
[~LSRC-mpls-tp-meg-test] me te interface Tunnel 20 mep-id 2 remote-mep-id 1
[*LSRC-mpls-tp-meg-test] commit

(Optional) Configure an interval at which CCMs are sent and a priority for CCMs.

The same interval at which CCMs are sent and priority of CCMs must be configured on the MEP and RMEP. If the configurations at both ends are different, an alarm indicating an error is reported.
# Set the interval at which CCMs are sent to 100 ms and the priority of CCMs to 6 on LSRA.
```
[~LSRA-mpls-tp-meg-test] cc interval 100
[*LSRA-mpls-tp-meg-test] cc exp 6
[*LSRA-mpls-tp-meg-test] commit
```
# Set the interval at which CCMs are sent to 100 ms and the priority of CCMs to 6 on LSRC.
```
[~LSRC-mpls-tp-meg-test] cc interval 100
[*LSRC-mpls-tp-meg-test] cc exp 6
[*LSRA-mpls-tp-meg-test] commit
```

Enable CC and CV.

# Enable CC and CV on LSRA.

[~LSRA-mpls-tp-meg-test] cc send enable
[*LSRA-mpls-tp-meg-test] cc receive enable
[LSRA-mpls-tp-meg-test] return

# Enable CC and CV on LSRC.

[~LSRC-mpls-tp-meg-test] cc send enable
[*LSRC-mpls-tp-meg-test] cc receive enable
[*LSRA-mpls-tp-meg-test] commit

Enable dual-ended frame LM.

# Enable dual-ended frame LM on LSRA.

[~LSRA-mpls-tp-meg-test] lost-measure dual-ended enable
[*LSRA-mpls-tp-meg-test] commit

# Enable dual-ended frame LM on LSRC.

[~LSRC-mpls-tp-meg-test] lost-measure dual-ended enable
[*LSRC-mpls-tp-meg-test] commit

Verify the configuration.

After completing the configurations, run the display mpls-tp oam command on LSRA to view frame loss statistics.

<LSRA> display mpls-tp oam meg test statistic-type lost-measure dual-ended
Dual-end loss measurement statistics:
Index Near-end lost frames Loss ratio Far-end lost frames Loss ratio
1     10                   12.50%     10                  12.50%
Max near-end lost frames:10,frame loss ratio:12.50%
Min near-end lost frames:10,frame loss ratio:12.50%
Average near-end lost frames:10,frame loss ratio:12.50%
Max far-end lost frames:10,frame loss ratio:12.50%
Min far-end lost frames:10,frame loss ratio:12.50%
Average far-end lost frames:10,frame loss ratio:12.50%

Configuration Files

LSRA configuration file

#
 sysname LSRA
#
 mpls lsr-id 1.1.1.1
 mpls
  mpls te
#
 bidirectional static-cr-lsp ingress Tunnel10
  forward nexthop 2.1.1.2 out-label 20
  backward in-label 20
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 2.1.1.1 255.255.255.0
 mpls
 mpls te
#
interface LoopBack1
 ip address 1.1.1.1 255.255.255.255
#
interface Tunnel10
 ip address unnumbered interface LoopBack1
 tunnel-protocol mpls te
 destination 3.3.3.3
 mpls te signal-protocol cr-static
 mpls te tunnel-id 100
 mpls te bidirectional
#
 ip route-static 2.2.2.2 255.255.255.255 2.1.1.2
 ip route-static 3.3.3.3 255.255.255.255 2.1.1.2
#
 mpls-tp meg test
  me te interface Tunnel10 mep-id 1 remote-mep-id 2
  cc send enable
  cc receive enable
lost-measure dual-ended enable
#
return

LSRB configuration file

#
 sysname LSRB
#
 mpls lsr-id 2.2.2.2
 mpls
  mpls te
#
 bidirectional static-cr-lsp transit lsp1
  forward in-label 20 nexthop 3.2.1.2 out-label 40
  backward in-label 16 nexthop 2.1.1.1 out-label 20
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 2.1.1.2 255.255.255.0
 mpls
 mpls te
#
interface GigabitEthernet0/1/8
 undo shutdown
 ip address 3.2.1.1 255.255.255.0
 mpls
 mpls te
#
interface LoopBack1
 ip address 2.2.2.2 255.255.255.255
#
 ip route-static 1.1.1.1 255.255.255.255 2.1.1.1
 ip route-static 3.3.3.3 255.255.255.255 3.2.1.2
#
return

LSRC configuration file

#
 sysname LSRC
#
 mpls lsr-id 3.3.3.3
 mpls
  mpls te
#
 bidirectional static-cr-lsp egress lsp1
  forward in-label 40 lsrid 1.1.1.1 tunnel-id 100
  backward nexthop 3.2.1.1 out-label 16
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 3.2.1.2 255.255.255.0
 mpls
 mpls te
#
interface LoopBack1
 ip address 3.3.3.3 255.255.255.255
#
interface Tunnel20
 ip address unnumbered interface LoopBack1
 tunnel-protocol mpls te
 destination 1.1.1.1
 mpls te signal-protocol cr-static
 mpls te tunnel-id 200
 mpls te passive-tunnel
 mpls te binding bidirectional static-cr-lsp egress lsp1 
#
 ip route-static 1.1.1.1 255.255.255.255 3.2.1.1
 ip route-static 2.2.2.2 255.255.255.255 3.2.1.1
#
 mpls-tp meg test
  me te interface Tunnel20 mep-id 2 remote-mep-id 1
  cc send enable
  cc receive enable
lost-measure dual-ended enable
#
return