Specifications

QSSC-S4R Technical Product Specification BMC Messaging Interfaces
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25.7.2 IPMB LUN Routing
The BMC can receive ei t her reques t or response I PMB messages . The t rea t men t o f t hese messages depends on t he
des t ina t ion logical uni t number (LUN) in t he I PMB message . For I PMB reques t messages , t he des t ina t ion LUN is t he
responder’s LUN . For I PMB response messages , t he des t ina t ion LUN is t he reques t er’s LUN . The disposi t ion o f t hese
messages is described in Table 197.BMC IPMB LUN Routing . The BMC accep t s LUN 00b and LUN 10b .
I PMB messages can be up t o 36 by t es , including I PMB header and checksums .
Table 197.BMC IPMB LUN Routing
LUN Name Messa
g
e Dis
p
osition
00b BMC Request messages with this LUN are:
 Passed to the BMC command handler for execution.
 Compared with outstanding BMC originated requests.
If there is a match, the BMC sub-system that sent the request
is notified. Otherwise the message is discarded.
01b Reserved Messages arriving with this LUN are discarded.
10b SMS All messages arriving with this destination LUN are placed in
the Receive Message Queue. If that buffer is full, the message
is discarded. No further action is completed.
11b Reserved Messages arriving with this LUN are discarded.
25.7.3 Management Engine IPMB
The BMC suppor t s an addi t ional I PMB-s t yle in t er f ace f or Managemen t Engine (ME) communica t ions . Al t hough t his
bus suppor t s I PMB and I PM I pro t ocols , i t is a priva t e bus .