TD0589: Reliable Time for VVoIP Software TOEs
FPT_STM_EXT.1/VVoIP does not take into account that a VVoIP software application TOE gets its time from the platform OS, not an ESC.
The introductory text for FPT_STM_EXT.1/VVoIP is modified as follows, with bold and underlines denoting additions:
The following SFR shall be claimed by the TOE if “register the TOE to an ESC…” is selected in FMT_SMF.1.1/VVoIP and the TOE is a hardware device. Note that if the TOE claims conformance to the NDcPP as its Base-PP, the TOE does not need to implement two distinct time services for different purposes. The same time service defined by FPT_STM_EXT.1 may be used here as well. Note however, for this PP-Module, if the TOE is a hardware device, it must use ESCs to which it is registered as its NTP time sources. If the TOE is a software VVoIP application, FMT_SMF.1.1/VVoIP is not required as the TOE relies upon the platform for time.
The first paragraph under the heading “FCS_NTP_EXT.1 NTP Protocol” on page 13 is modified as follows, with bold and underlines denoting additions:
FCS_NTP_EXT.1 NTP Protocol
This SFR is selection-based in the NDcPP and remains selection-based in this PP-Module. However, an additional trigger for this SFR’s inclusion is added for the selection of “register the TOE to an ESC…” in FMT_SMF.1/VVoIP if the TOE is a hardware device. This is because any hardware-based VVoIP TOE that can be registered to ESCs is required to use them as NTP servers.
As described in the rationale for FPT_STM.1 – Reliable time stamps in table 14 of MOD_VVOIP_V1.0, the PP_APP_1.3 has an assumption for the TOE to rely upon a trustworthy computing platform with a reliable time clock.