From Zenitel Wiki
Zenitel products are not impacted be the SPECTRE/Meltdown Vulnerability. The SPECTRE/Meltdown Vulnerability impact following CPU cores (https://en.wikipedia.org/wiki/Meltdown_(security_vulnerability) )
- Intel x86
Zenitel products are using the following CPUs:
- INCA (MIPS core)
- AMC IP (Intel xscale core)
- Turbine (ARM with ARM926EJ-S™ core core)
No Xscale and MIPS core are impacted. The ARM core Zenitel use is also not impacted. See https://developer.arm.com/support/security-update. It is only some version of the ARM Cortex family that is impacted.