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2.33 CEE Function
CEE (Converged Enhanced Ethernet) function is the one by which the extensions required to integrate the
different types of conventional communications, such as LAN, IPC, and SAN etc in one network is added in
Ethernet. It is used in FCoE (Fibre Channel over Ethernet) which is used to send/receive the Fibre Channel from
SAN (Storage Area Network) protocol by Ethernet. In this device, element technologies shown below are
supported as CEE functions.
ETS (Enhanced Transmission Selection)
It is a function used to summarize the flow of multiple traffic class (Traffic Class or Priority) as Traffic class
group (Traffic class group or Priority Group PG) and to secure the smaller region of each traffic class group by
restricting the quantity of flow. It is examined as IEEE802.1 Qaz. It is assumed that, different types of
communications such as LAN, IPC, and SAN etc are assigned in each Traffic class group.
DCBX (Data Center Bridging eXchange)
It defines the information exchanged between peer of CEE device and examined as one part of ETS (IEEE802.1
Qaz). It notifies both the ETS and PFC setting information of each peer and process by which setting is
adjusted is executed. Implemented as LLDP extension.
PFC (Priority-based Flow Control)
Though the flow control function explained in section 2.2 is considered as control of link level, it is extended
such that the flow of each Priority can be controlled therefore it is examined as IEEE802.1 Qbb. For example,
PFC is enabled for the Priority or PG which passes through the weak protocol in frame loss such as FCoE and it
is assumed that there is an operation to disable the PFC for the flow obtained by high throughput even if loss
is accepted.
Points to be noted
Though enable/ disable in each port or linkaggregation can be set by CEE function, band control and PFC control
cannot be secured when frame is transferred during enable/ disable of CEE function and between the ports with
different settings. Whether to uniform the settings by all port or it should set in such a way that, the frame is not
transferred by enable/ disable of CEE functions or between the ports with different settings by using the settings
of egress permission command or VLAN.
CEE function cannot be used simultaneously with mirror target function, output rate control function and
LAN
IP
FCoE enabled switch
DCBX
DCBX
IP
CNA expansion board
SAN
Fibre Channel
IP
FCoE
FCoE
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