Medium Access Control (MAC) and Physical Layer (PHY) - CISE

4-June-07 P1901_PRO_016_r0
• Priority Congestion Management Policy (PCMP): lower priority traffic performance is decreased in
order to guarantee higher priority traffic SLA. Therefore, access to the channel is denied to lower service
types first, until SLA of higher service types can be maintained.
• “Quality Service” Congestion Management Policy (QSCMP): The congestion manager will act like as
Priority Congestion Management but uses the service class and the quality session parameters to perform
the scheduling and the acceptance criteria for new sessions. The sessions with higher quality session values
will have more probabilities to be scheduled accomplishing its requirements when network is congested.
Quality Session parameter can be also a mixture of priority and age, or an arbitrary parameter defined by
the network operator.
8.3.1 Configuration
The Congestion Management can be configured using the Auto-configuration protocol. In this section, we
enumerate the auto-configuration parameters that modify the behavior of the Congestion Management. For more
information, see 11.
QOS_BW_POLICY = [0|1|2] configures the CM in which the QoS manages the network in the event of congestion
(0 configures the CM in FCMP mode; 1 configures the CM in PCMP mode; 2 configures the CM in QSCMP
mode).
8.4 CONNECTION ADMISSION CONTROL
Initiation of a Connection Admission Control (CAC) procedure is required for any connected flow. The mission of
the Connection Admission Control is to ensure that the BPL network can deliver the agreed services and guarantees
to new flows while maintaining the requested performance of already accepted flows.
The Connection Admission Control functionality is embedded inall the network. The CAC protocol might be used
in the following two scenarios:
• Before the transmission of a connected flow, the CAC shall be used to reserve resources on the nodes in the
system that collaborates in the communication of the new flow (from the node initiating the flow to the
nodethat shall guarantee the flow). The CAC requests made to commit resources for a given Service Class
may be new or updates from previous reservations.
• At the end of the transmission of a connected flow, resources may be released. Release of resources may be
done explicitly by transmitting a CAC Stop message indicating traffic flow is not longer needed, or may be
done when a timer, MAX_CAC_DRP_TO expires since the last time a Data Token with the Session ID of
the traffic was received by the node.
In the CAC protocol, the exchanged parameters to verify whether or not the BPL network can guarantee the
required service shall include the required bandwidth, and the maximum latency demanded by the new node.
Submission page 184 UPA-OPERA