| Description | A table of Extended package objects used for the
management of the queue_sets. Entries are control and
status indication objects of an EPON interface, which
are gathered in an extended package as an addition to
the objects based on the [802.3ah] attributes. The
objects in this table are specific for the queue_sets,
which are reported in the MPCP REPORT message as defined
in [802.3ah], clause 64.
The [802.3ah] MPCP defines a report message of the
occupancy of the transmit queues for the feedback BW
request from the ONUs. These queues serve the uplink
transmission of the ONU and data is gathered there until
the ONU is granted for transmission.
The management table of the queues_sets is added here
mainly to control the reporting and to gather some
statistics of their operation. This table is not
duplicating existing management objects of bridging
queues, specified in [802.1d], since the existence of a
dedicated transmit queuing mechanism is implied in the
[802.3ah], and the ONU may be a device that is not a
bridge with embedded bridging queues.
The format of the REPORT message, as specified
in [802.3], is presented below:
+-----------------------------------+
| Destination Address |
+-----------------------------------+
| Source Address |
+-----------------------------------+
| Length/Type |
+-----------------------------------+
| OpCode |
+-----------------------------------+
| TimeStamp |
+-----------------------------------+
| Number of queue Sets |
+-----------------------------------+ /|\
| Report bitmap | |
+-----------------------------------+ |
| Queue 0 report | |
+-----------------------------------+ | repeated for
| Queue 1 report | | every
+-----------------------------------+ | queue_set
| Queue 2 report | |
+-----------------------------------+ |
| Queue 3 report | |
+-----------------------------------+ |
| Queue 4 report | |
+-----------------------------------+ |
| Queue 5 report | |
+-----------------------------------+ |
| Queue 6 report | |
+-----------------------------------+ |
| Queue 7 report | |
+-----------------------------------+ \|/
| Pad/reserved |
+-----------------------------------+
| FCS |
+-----------------------------------+
As can be seen from the message format, the ONU
interface reports of the status of up to 8 queues
and it can report in a single MPCP REPORT message
of a few sets of queues.
The number of queue_sets defines the number of the
reported sets, and it can reach a value of up to 8.
It means that an ONU can hold a variable number of
sets between 0 and 7.
The dot3ExtPkgQueueSetsTable table has a variable
queue_set size that is limited by the
dot3ExtPkgObjectReportMaximumNumThreshold object as an
ONU can have fewer queue_sets to report.
The 'Queue report' field reports the occupancy of each
uplink transmission queue. The queue_sets can be used to
report the occupancy of the queues in a few levels as to
allow granting, in an accurate manner, of only part of
the data available in the queues. A Threshold is
defined for each queue_set to define the level of the
queue that is counted for the report of the occupancy.
The threshold is reflected in the queue_set table by the
dot3ExtPkgObjectReportThreshold object.
For each queue set, the report bitmap defines which
queues are present in the report, meaning that
although the MPCP REPORT message can report of up to 8
queues in a REPORT message, the actual number is
flexible.
The dot3ExtPkgQueueSetsTable table has a variable queue
size that is limited by the
dot3ExtPkgObjectReportMaximumNumQueues object as an ONU
can have fewer queues to report.
Each object has a row for every virtual link, for each
queue in the report and for each queue_set in the queue.
The LLID field, as defined in the [802.3ah], is a 2-byte
register (15-bit field and a broadcast bit) limiting the
number of virtual links to 32768. Typically the number
of expected virtual links in a PON is like the number of
ONUs, which is 32-64, plus an additional entry for
broadcast LLID (with a value of 0xffff).
The number of queues is between 0 and 7 and limited by
dot3ExtPkgObjectReportMaximumNumQueues.
The number of queues_sets is between 0 and 7 and limited
by dot3ExtPkgObjectReportMaximumNumThreshold. |