Data Sheet

Ethernet Controller I210 —System Manageability
766
Note that the MAC header and MAC FCS present when working over NC-SI are not part of the packet in
MCTP mode.
10.7.5.1.2 Pass Through Packets
The format used for Pass through packets is as follow. This format is the same for either packets
received from the network or packets received from the host.
The CRC is never included in the packet. In receive, the CRC is checked and removed by the I210 in
transmit, the CRC is added by the I210.
The CRC presence depends on the IC bit value. If the IC bit is set, the packet includes a CRC. If it is
cleared the packet doesn’t include it.
For the I210 to MC packets, the IC bit will always be set. For MC to the I210 packets, if the IC bit is set,
the I210 must check the CRC validity.
In any case, if the packet is modified by the I210, then a new CRC must be recalculated.
10.7.6 MCTP Programming
The MCTP programming model is based on:
1. A set of MCTP commands used for the discovery process and for the link management. The list of
supported commands is described in section Section 10.7.6.1.
2. A subset of the NC-SI commands used in the regular NC-SI interface, including all the OEM
commands as described in Section 10.6.2 (NC-SI programming I/F). The specific commands
supported are listed in Table 10-31 and Table 10 -34.
Note: For all MCTP commands (both native MCTP commands and NCSI over MCTP), the response
uses the Msg tag received in the request with TO bit cleared.
+0 +1 +2 +3
76543210765432107654321076543210
SMBus or PCIe header
MCTP
Reserved
Header
version = 1
Destination endpoint ID Source endpoint ID
S
O
M
E
O
M
SEQ#
T
O
=
1
Tag
I
C
=
0
Message Type = Pass
Through Packets Control
Type (0x03)
DA
DA SA
SA
SA Ether type Ethernet Packet
Ethernet packet
....
....