Configuring Y.1731 Functions in VLL Networking

This section describes how to configure Y.1731 functions, including single-ended frame loss measurement, dual-ended frame loss measurement, one-way frame delay measurement, and two-way frame delay measurement in VLL networking.

Application Scenario

The VLL technology implements point-to-point VPN networking. As shown in Figure 1, the PEs are connected through a PW. To collect accurate statistics about frame loss on one end of a PW or an AC in VPLS networking, the performance monitoring functions defined by Y.1731 can be used to monitor links.

Figure 1 Networking diagram for configuring Y.1731 functions in VLL networking

Pre-configuration Tasks

Before configuring Y.1731 functions in VLL networking, complete the tasks listed in Table 1.

**Table 1** Pre-configuration tasks for configuring Y.1731 functions in VLL networking
Function	Pre-configuration Tasks
Configuring Y.1731 functions (single-ended frame loss measurement, dual-ended frame loss measurement, one-way frame delay measurement, and two-way frame delay measurement) for an AC in VLL networking	Completing VLL-related configurations on PEs For details, see the chapter "VLL Configuration" in the NetEngine 8000 F Configuration Guide - VPN. Completing VLAN-related configurations on CEs Completing CFM-related configurations and configuring the MEP type as outward
Configuring Y.1731 functions (single-ended frame loss measurement, dual-ended frame loss measurement, one-way frame delay measurement, and two-way frame delay measurement) for a PW in VLL networking	Completing VLL-related configurations on PEs For details, see the chapter "VLL Configuration" in the NetEngine 8000 F Configuration Guide - VPN. Completing CFM-related configurations and configuring the MEP type as inward

Binding an MA to a VLL: Binding an MA to a VLL is a prerequisite for configuring single-ended frame loss measurement, dual-ended frame loss measurement, one-way frame delay measurement, two-way frame delay measurement.

Configuring Single-ended Frame Loss Measurement in VLL Networking: In VLL networking, CFM is enabled. CCMs are not used to monitor link connectivity, preventing them from using excessive network bandwidth resources. If frame loss measurement needs to be performed for a link, single-ended frame loss measurement can be configured to monitor the link quality.

Configuring Dual-ended Frame Loss Measurement in VLL Networking: In VLL networking, CFM is enabled to monitor link connectivity. If accurate frame loss measurement needs to be performed for a link, dual-ended frame loss measurement can be configured to monitor the quality of the link.

Configuring One-way Frame Delay Measurement in VLL Networking: In VLL networking, the clock frequencies between the two ends are synchronized and CFM is enabled to monitor link connectivity. If the unidirectional delay measurement needs to be performed for a link, one-way frame delay measurement can be configured to monitor the quality of the link.

Configuring Two-way Frame Delay Measurement in VLL Networking: In VLL networking, the clock frequencies between the two ends are not synchronized and CFM is enabled to monitor link connectivity. If the bidirectional delay measurement needs to be performed for a link, two-way frame delay measurement can be configured to monitor the quality of the link.

Configuring Single-ended SLM in VLL Networking: This section describes how to configure single-ended synthetic loss measurement (SLM) in virtual leased line (VLL) networking. To collect performance statistics for frame loss on point-to-multipoint or multipoint-to-multipoint links, deploy single-ended SLM, which helps monitor link quality.

Configuring the ETH-Test Function for a VLL: The ETH-test function is short for Ethernet test signal. ETH-test instances are performed for a unidirectional on-demand service or during an on-demand-service interruption to calculate parameters, including the maximum bandwidth, frame loss ratio, and bit error rate.

Configuring AIS: Configuring AIS prohibits a MEP in an MD of a higher level from sending the same alarm as that sent by a MEP in an MD of a lower level to the NMS.