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<p class="MsoNormal">Nancy,<o:p></o:p></p>
<p class="MsoNormal">As IPMI is still a legacy so ipmb will still be used I guess
<span style="font-family:"Apple Color Emoji"">😊</span>. Once MCTP starts getting supported widely and they become more stable and generic then it can be used. But currently it is still a challenge to use across all devices.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">-Vijay<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">Nancy Yuen <yuenn@google.com><br>
<b>Date: </b>Wednesday, April 29, 2020 at 6:32 PM<br>
<b>To: </b>Vijay Khemka <vijaykhemka@fb.com><br>
<b>Cc: </b>OpenBMC Maillist <openbmc@lists.ozlabs.org><br>
<b>Subject: </b>Re: Multiple BMCs in a system: IPMB? Redfish? MCTP?<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Vijay, I wonder if IPMB would still be used in later generations or would something like MCTP be considered?<br clear="all">
<o:p></o:p></p>
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<p class="MsoNormal">----------<br>
Nancy<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, Apr 29, 2020 at 5:42 PM Vijay Khemka <<a href="mailto:vijaykhemka@fb.com">vijaykhemka@fb.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Nancy,<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">We have multiple hosts which has a small controller called BIC (Bridge IC). This BIC on each host connected via i2c to main BMC and communicates through ipmi messages to BMC over
IPMB/i2c.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Regards<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">-Vijay<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">Nancy Yuen <<a href="mailto:yuenn@google.com" target="_blank">yuenn@google.com</a>><br>
<b>Date: </b>Wednesday, April 29, 2020 at 5:25 PM<br>
<b>To: </b>Vijay Khemka <<a href="mailto:vijaykhemka@fb.com" target="_blank">vijaykhemka@fb.com</a>><br>
<b>Cc: </b>OpenBMC Maillist <<a href="mailto:openbmc@lists.ozlabs.org" target="_blank">openbmc@lists.ozlabs.org</a>><br>
<b>Subject: </b>Re: Multiple BMCs in a system: IPMB? Redfish? MCTP?</span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Neeraj, I was not considering aggregation in this case, just having the intermediate BMC "route".
<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Vijay, thanks. I was wondering what your applications for IPMB were for. What's the rationale for using IPMB vs something else? In your multihost system, one BMC supports multiple
host CPUs? Are there also multiple BMCs?<o:p></o:p></p>
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<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">----------<br>
Nancy<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Wed, Apr 29, 2020 at 5:15 PM Vijay Khemka <<a href="mailto:vijaykhemka@fb.com" target="_blank">vijaykhemka@fb.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hi Nancy,<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">We are currently using (1) in our current multi host design. Option (3) also looks good.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Regards<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">-Vijay<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">openbmc <openbmc-bounces+vijaykhemka=<a href="mailto:fb.com@lists.ozlabs.org" target="_blank">fb.com@lists.ozlabs.org</a>> on behalf of Nancy Yuen <<a href="mailto:yuenn@google.com" target="_blank">yuenn@google.com</a>><br>
<b>Date: </b>Wednesday, April 29, 2020 at 3:53 PM<br>
<b>To: </b>OpenBMC Maillist <<a href="mailto:openbmc@lists.ozlabs.org" target="_blank">openbmc@lists.ozlabs.org</a>><br>
<b>Subject: </b>Multiple BMCs in a system: IPMB? Redfish? MCTP?</span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I've talked with some people a while back (long while back) about multiple BMCs in a system. Either for redundancy or managing separate parts of a system. I'm wondering what
other people are thinking in this area if at all.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">We are considering similar designs and I'm looking into options for BMC-BMC communications. Some BMCs may not be externally accessible. Here are some options that we've looked
at:<o:p></o:p></p>
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<ol start="1" type="1">
<li class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1">
i2c/IPMB<o:p></o:p></li><li class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1">
usbnet/Redfish<o:p></o:p></li><li class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1">
i2c/MCTP/PLDM or something else?<o:p></o:p></li><li class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1">
internal network via switch chip/Redfish or MCTP<o:p></o:p></li></ol>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> I'd like to reduce our use of IPMI so I want to avoid (1).<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">----------<br>
Nancy<o:p></o:p></p>
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