Table of Contents
Advertisement
IEEE802.1Q tunneling function. When CEE function is defined in valid port; same port cannot be used.
When CEE function is in valid port, the settings of queue specifications and queue change function become
disabled by ACL for ETHER port.
When CEE function is in valid port, priority control function using WRR and WDRR, the settings of queue
specifications and queue change function by ACL for VLAN, flow control function of link level explained in section
2.2 and settings of save queue in each priority by qos cosmap command are ignored.
When traffic class group 15 is used, traffic class group 15 is transferred to maximum priority and the traffic class
groups other than this transfers the remaining bands by dividing it with the ratio of bandwidth that is
respectively specified.
PFC becomes enabled only after the negotiation between peers is completed by DCBX.
The length of output queue related to the frame of valid traffic class group is not restricted by PFC irrespective of
the settings of buffermode command. Therefore, there is a possibility that the other traffic class group or frames
of other port address discarded easily by PFC, in the situation wherein lots of frame of valid traffic class group are
accumulated.
CEE function is enabled for the frames having size less than 2300 Bytes. The flow control does not functioned
effectively for the frames having size more than this and the band control might not be as per expectations.
Though the band of the traffic class group is specified in percentage, there is a limitation on the ratio of
minimum band and maximum band that can be actually controlled. When only 2 traffic class groups to which PFC
is disabled are defined, the ratio of minimum band and maximum band will be 1:14. When only 3 traffic class
groups to which PFC is enabled are defined, the ratio of minimum band and maximum band will be 1:7.
Moreover, when traffic class groups to which PFC is disabled are defined, the ratio of minimum band and
maximum band will be approximately 1:4. For example, when PFC is used and defined by valid traffic class group
and invalid traffic class group respectively for the port of 10Gbps and even if the band is set to 10 and 90, actually
it is controlled by 2Gbps and 8Gbps.
Page 70 of 71
Advertisement
Table of Contents
