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

4-June-07 P1901_PRO_016_r0
CAC_Rsp ; Reponse from the master.
CAC_Chg ; Inform the master of a change in the allocated resources.
CAC_Chg_Rsp ; Contains the response to a CAC_Req.
CAC_Drp: Master or Repeater tells a node it shall cancel its reservation.
CAC_Stp: Inform the FMN that a traffic flow has stopped (thus that its resources can be freed).
Flow Master Node (FMN) is defined as the BPL node in charge of guarantee QoS requirement for a registered
flow. All CAC_Req messages are transmitted from the source node which request flow to the BPL subcell master of
the node. This request may be propagated to the HE, in this situation FMN of the requested flow will be network
HE, or could be blocked by an intermediate node if this node decides to be the FMN of the requested flow.
Destination MAC address of CAC messages:
CAC_Req/CAC_Chg/CAC_Stp messages are transmitted by a BPL node and it shall be addressed to its BPL
subcell master, these messages will be propagated in the network hop by hop until arrive to the FMN of the flow.
These messages have as source MAC the MAC of the node that request the flow and as destination MAC the MAC
of the BPL subcell master.
CAC_Rsp/CAC_Chg_Rsp/CAC_Drp messages are transmitted by the FMN in downstream to the node which
request the flow. CCP source address will be the MAC of the FMN and the destination MAC, the address of the
directly connected slave that is part of the requested flow.
CAC_Req
The CAC_Req message is transmitted to request QoS Resources to be committed in order to satisfy the agreed
quality parameters. It may be originated from any node except network HE. There are two subtypes Slave
CAC_Req and Master CAC_Req.
CAC_Req sequence is triggered by a CPE or Repeater node upon detection of a specific flow or statically after node
configuration. A node requesting resources must trigger a CAC_Req sequence by sending a CAC_Req message to
its master node. Master node then decides if can guarantee requested flow and can reply the request with a
CAC_Rsp message, in this case Master node will become the FMN of the requested flow (the node that should
guarantee flow requirements). In order to guarantee requested flow guarantees, FMN can trigger a new CAC_Req
message to its master or use existing resources to guarantee the flow.
If a node decides to be the FMN of a specific user flow, it must be the FMN of the totality of flows for this user.
Submission page 252 UPA-OPERA