mscAtmIfEpMinimumBandwidthGuarantee
1.3.6.1.4.1.562.36.2.1.114.10.100.1.1
This attribute specifies the minimum bandwidth guarantee
associated with this EmissionPriority. A minimum bandwidth
guarantee is designed to prevent starvation of traffic at this EP by
traffic at higher EPs. Minimum bandwidth guarantees only operate
for EPs within the guaranteed bandwidth range 2 through 7. Note,
that for APC-based cards, EPs 5 and 6 are not supported.
The minimum bandwidth guarantee specified is a percentage of the
bandwidth which remains after all traffic at EP 0 and EP 1 is served.
For example, if EP 0 and EP 1 traffic consumes 20% of link
bandwidth, the minimum bandwidth guarantee applies to the
remaining 80% of the link bandwidth. A minimum bandwidth
guarantee of 2% would actually result in this EP getting 2% of 80%
(total 1.6%) of the link bandwidth.
The sum of minimumBandwidthGuarantee values for all Eps under
an AtmIf must not exceed 100%.
The value priority specifies that this Ep gets the bandwidth
guarantee which is applicable based on the hierarchy of emission
priorities. In this case, there is no minimum bandwidth guarantee.
For all non Apc-based cards the allowed value of the attribute is
between 0 and 48. Such a value specifies that from 1% to 48% of
the remaining link bandwidth is reserved for traffic at this EP. Given
a value n of minimumBandwidthGuarantee, then for n% of transmit
cell opportunities in the guaranteed bandwidth range, this EP get
first opportunity to send a cell. If this EP uses less than n% of the
link bandwidth, the extra opportunities are allocated in priority. Due
to scheduling and cell arrival times, traffic at this EP may not
necessarily achieve full utilization of its minimum bandwidth
guarantee.
When specifying a value for minimumBandwidthGuarantee,
consider the effect on cell delay variation (CDV) of traffic which
would normally be of higher priority. For example, if RtVbr service
category traffic is assigned to Ep/2 and Ubr traffic is assigned on
Ep/7 where Ep/7 has a minimumBandwidthGuarantee of 25%, there
can be a large impact on CDV of the RtVbr traffic. Traffic of the
Cbr or RtVbr service category which is sensitive to CDV and is of
known volume, can be assigned on EP 0 or EP 1 which are
independent of the effects of minimum bandwidth guarantee.
VALUES (
0 = priority
)