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Sonus supports either host-passthrough or host-model for non-S/M/T-SBC instances; this includes the SBC Configurator.

S/M/T-SBC Instances

Sonus recommends setting CPU Mode to host-passthrough for SBC instances so every detail of the host CPU can be known by SBC SWe. The host-model setting impacts how CPU L2 / L3 cache information is communicated to the guest OS since the libvert emulated CPU does not accurately represent the L2 and L3 CPU hardware caches to the guest OS.  In performance testing of the Sonus SBC, Sonus has seen significant performance degradation, which goes beyond just a simple reduction in capacity. This results in signaling latency and jitter that is outside of acceptable limits even at modest loads.

This setting is defined in /etc/nova/nova.conf:

This change is made in /etc/nova/nova-compute.conf:

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Apply below settings to all Nova compute hosts where Sonus VMs are installed:

• EMS
• PSX-M
• PSX-Replica
• S-SBC
• M-SBC
• T-SBC
• SBC Configurator

The CPU model defines the CPU flags and the CPU architecture that is exposed from the host processor to the guest. Modify nova.conf file located at /etc/nova/nova.confand set CPU-. Sonus recommends setting CPU Mode to host-passthrough that helps SBC SWe to know for SBC instances so every detail of the host CPU can be known by SBC SWe. The host-model setting impacts how CPU L2 / L3 cache information is communicated to the guest OS since the libvert emulated CPU does not accurately represent the L2 and L3 CPU hardware caches to the guest OS. In performance testing of the Sonus SBC, Sonus has seen significant performance degradation that , which goes beyond just a simple reduction in capacity. This results in signaling latency and jitter that is outside of acceptable limits even at modest loads.

This setting is defined in /etc/nova/nova.conf:

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This change is made in /etc/nova/nova-compute.conf:

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Removal of CPU and Memory Over Commit

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