User's Manual

ALFOplus 24GHz (North America) - Release 01.05.0x - MN.00395.E - 004 61
After the Hold-Time expires, the MEP detects the SD defect condition and the Cisco MWR will perform the
following actions:
• Issue a Syslog message that displays the Nominal Tx BW as well as the Current Tx BW.
• Evaluate, based on the degradation in BW, which ERP instances need to be failed over and trigger
the failover for these instances.
For the duration of the fading event, any subsequent VSM messages received will trigger the following ac-
tions:
• If the reported Current Tx BW is different from the value previously received, issue a Syslog mes-
sage that displays the Nominal Tx BW as well as the Current Tx BW.
• If the reported Current Tx BW is the same as the one previously received, then no further action is
taken.
• If the reported Current Tx BW is less than the one previously received, evaluate which additional
ERP instances need to be failed over, and trigger failover for these instances.
• If the reported Current Tx BW is more than the one previously received, then no further action is
taken
When the fading subsides and the MEP receives a BW-VSM indicating that the Current Tx BW is equal to
the Nominal Tx BW, the switch then starts a Fading Wait-to-Restore timer M. M will be configurable in 1
sec increments from 0 to 600 seconds. If the timer expires before receiving any further BW-VSMs, then
the MEP clears the SD defect condition associated with the ERP instances.
In case the BW-VSM announcing the return to nominal BW is lost, the MEP will detect that it has stopped
receiving periodic BW-VSM frames. In this case, the MEP waits for 3.5 times the BW-VSM transmission in-
terval, and then starts the Fading Wait-to-Restore timer. When the timer expires, the MEP clears the SD
defect condition.
Equipment setup parameters
In order to modify the management parameters of the BW-VSM messages (MAB), the following parameters
have to be set (refer to the image below):
• Enable/disable the management of the BW-VSM messages at level of single LAN port
• Define the parameters for the forwarding of the BW-VSM messages:
- the Tag 802.1Q VLAN value in the TX VLan ID box (value between 2 and 4094). By default, the
BW-VSM message is sent untagged (value 0)
- Maintenance Level of the OAM domain in the TX OAM Maint. Level box (value between 0 and 7).
The Default value is 0. This setting involves even the change of the destination MAC address of
the BW-VSMmessage because this address corresponds to the CCM multicast address for the
associated OAM maintenance level (the CCM multicast address depends on the CISCO equip-
ment configuration)
- in the Fading Hold Off (s) box, set the waiting period (in seconds) before declaring Fading and
starting the transmission of BW-VSM messages (value between 10 and 60). The lesser is this
value, the faster will be the reaction of the device after a fading phenomena. However, small
values of the Fading Hold Off parameters can cause instability in the device in presence of fast
phenomena. The default waiting period is 10 seconds
- in the TX Period box, set the transmission period (in seconds) between one BW-VSM message
and the next one (1, 10 or 60 seconds). The default waiting period is 10 seconds. The same
value has to be set into CISCO equipment as well
- in the BW Tx Type box, set the criterion used to calculate the band value available within every
transmission period (Tx Period):
- Average: The BW-VSM messages contain the indication of the average value of the available
band within the observation period
- Min: The BW-VSM messages contain the indication of the minimum value of the available
band within the observation period
- Max: The BW-VSM messages contain the indication of the maximum value of the available
band within the observation period