Users Guide

Table 7. Continuity Check Message Processing

Frames at Frames from UP-MEP Action Down-MEP Action MIP Action

Less than my level Bridge-relay side or Wire

side

Drop Drop Drop

My level Bridge-relay side Consume Drop Add to MIP-DB and

forward

My level Wire side Drop Consume add to MIP-DB and

forward

Greater than my level Bridge-relay side or Wire

side

Forward Forward Forward

All the remote MEPs in the maintenance domain are defined on each MEP. Each MEP then expects a periodic CCM from the configured

list of MEPs. A connectivity failure is then defined as:

• Loss of three consecutive CCMs from any of the remote MEP, which indicates a network failure.

• Reception of a CCM with an incorrect CCM transmission interval, which indicates a configuration error.

• Reception of a CCM with an incorrect MEP ID or MAID, which indicates a configuration or cross-connect error. This error could

happen when different VLANs are cross-connected due to a configuration error.

• Reception of a CCM with an MD level lower than the receiving MEP, which indicates a configuration or cross-connect error.

• Reception of a CCM containing a port status/interface status TLV, which indicates a failed bridge or aggregated port.

The continuity check protocol sends fault notifications (Syslogs, and SNMP traps, if enabled) whenever you encounter any of the these

errors.

Enabling CCM

To enable CCM, use the following commands.

1. Enable CCM.

ECFM DOMAIN mode

no ccm disable

The default is Disabled.

2. Configure the transmit interval (mandatory). The interval specified applies to all MEPs in the domain.

ECFM DOMAIN mode

ccm transmit-interval seconds

The default is 10 seconds.

Enabling Cross-Checking

To enable cross-checking, use the following commands.

1. Enable cross-checking.

ETHERNET CFM mode

mep cross-check enable

The default is Disabled.

2. Start the cross-check operation for an MEP

ETHERNET CFM mode

mep cross-check mep-id

3. Configure the amount of time the system has to wait for a remote MEP to come up before the cross-check operation is started.

ETHERNET CFM mode

mep cross-check start-delay number

802.1ag