ACE-3105, ACE-3205 Ver. 5.2
1BPSN-to-ATM Alarm Forwarding
F-1
Appendix
F
Alarm Forwarding
When interworking between ATM/TDM ends and packet-switched networks, it is
necessary to deliver alarms from end-to-end. The ACE-3105, ACE-3205 alarm
forwarding mechanism translates PSN and ATM/TDM link failures to alarms that
are sent to the customer equipment on each end of the application.
In all ATM over PSN applications, ACE-3105, ACE-3205 sends either F4 or F5
Segment/End-to-End AIS alarms towards the ATM backbone side, and performs
VCCV-BFD connectivity checks with the PSN side. In addition, the ATM point is
configured as VP or VC Intermediate or segment point. All F4/F5 OAM cells that
are received on the ATM interface are encapsulated by ACE-3105, ACE-3205 over
the PSN.
In all TDM over PSN applications, the alarms are propagated using designated bits
in the encapsulated PW's Control Word, as well as via LOS, AIS, and RAI signals
towards/from the TDM ends.
F.1
PSN-to-ATM Alarm Forwarding
Failures on the PSN side are propagated by ACE-3105, ACE-3205 towards the
ATM side. The following figures illustrate the unit's behavior and alarm types used
in case of logical/physical Ethernet link failures, depending on the ATM
connection type/assignment (VP or VC, Intermediate or Segment point).
VP/VC Intermediate Point
When the ATM interface is defined as Intermediate point, the following
forwarding cases are possible:
Figure
F-1. PW Link Failure in case of VP Intermediate Point
