S/UNI®-ATLAS-3200 Telecom Standard Product Data Sheet
Preliminary
10.9.2 Loopback Cells
The S/UNI-ATLAS-3200 provides support for generating Returned Loopback cells via the
BCIFs. Generation of parent loopback cells is left up to the microprocessor.
If enabled, loopback cells will have their Loopback Indication and Loopback Location ID
examined. Cells with Loopback Indication = 0 will be dropped and routed to the Microprocessor
Cell Interface at flow end-points, and at intermediate points whose Loopback Location ID
Register matches the Source ID Field of the loopback cell. For cells with Loopback Indication =
1, segment Loopback cells will be dropped and looped back if their Loopback Location ID
matches the Loopback Location ID register, and looped back but not dropped if their Loopback
Location ID is all-zeroes. Both segment and end-to-end cells will be dropped and looped back at
flow end points if their Loopback Location ID is all-ones. In any event, Loopback cells are
always dropped at flow end points. Cells which are looped back always have their Loopback
Indication bit set to 0, and their Loopback Location ID replaced with the contents of the
Loopback Location ID Register.
Alternately, loopback cells may also be routed to the microprocessor for external processing.
10.9.3 Activation/Deactivation Cells
Activation/Deactivation cells are identified with an OAM Cell Type of 1000. They are used by
the management entity to implement the handshaking required to initiate or cease the
Performance Management or Continuity Check processes.
The S/UNI-ATLAS-3200 does not process these cells. If this S/UNI-ATLAS-3200 is not an end-
point for an OAM flow, all Activate/Deactivate cells are passed to the Output Cell Interface. If
the S/UNI-ATLAS-3200 is an OAM flow end-point, the Activate/Deactivate cells are optionally
passed to the Microprocessor Cell Interface or to the Output Cell Interface. The flow of
Activate/Deactivate cells is controlled by the ACTDEtoUP, ACTDEtoBCIF and ACTDEtoOCIF
register bits.
10.9.4 System Management Cells
System Management cells are identified with an OAM Cell Type of 1111. Their use is largely for
security puposes, and is under consideration by the ITU. The S/UNI-ATLAS-3200 does not
process these cells. If the S/UNI-ATLAS-3200 is not a flow end-point for an OAM flow, all
System Management cells are passed to the Output Cell Interface. If the S/UNI-ATLAS-3200 is
an OAM flow end-point, the System Management cells are optionally passed to the
Microprocessor Cell Interface.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990553, Issue 4
107
PMC [ PMC-SIERRA, INC ]
