255-700-019
3-31
PacketStar
™
PSAX 20 Access Concentrator User Guide
, Issue 1
Release 6.3.0
Chapter 3 System Features
PSAX 20 Software Features
~
Network-to-endpoint loopback: An end-to-end loopback cell is
inserted by one network operator, and looped back by the end point in
another domain.
~
Intradomain loopback: A segment loopback is inserted by a
connection/segment end point or a connecting point, and looped back
by a segment or a connecting point. For this application, the use of the
loopback location identifier is a network operator option.
Activation/Deactivation
Activation/deactivation is an in-service OAM mechanism used to remotely
start and stop the generation of cells that perpetually monitor performance
and continuity.
A VPC or VCC end or connecting point (the source) sends an activation or
deactivation request to the receiving point. The receiving point responds by
either confirming or denying the request. On receiving an activation
confirmation, the source or receiver (depending on the direction of the
action) periodically generates performance management or continuity check
cells.
Characteristics of
OAM Activation /
Deactivation Cells
The activation/deactivation cells are OAM cells with the function-specific
fields shown in Figure 3-9.
•
Message ID: indicates whether to request, confirm, or deny the activation
or deactivation of cells
•
Directions of Action: direction (s) in which to start/stop generating
performance management or continuity cells
~
A-B (ingress): away from the activator/deactivator
~
B-A (egress): toward the activator/deactivator
~
both: bidirectional
•
Correlation Tag: number used to correlate transmitted
activation/deactivation requests with their responses
•
PM Block Size (A-B, B-A): This feature works with activation requests
only. It monitors the size of user cell blocks used to monitor the
performance in the forward or backward direction (default is 1,024 cells).
Figure 3-9. OAM Activation/Deactivation Cells
Message
ID
Directions
of Action
Correlation
Tag
PM Block
Size A-B
PM Block
Size B-A
Unused
6
2
8
4
4
336 bits (42 bytes)
Summary of Contents for PacketStar PSAX 20
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