Not specifically that i know of - I mean, a trunk's a trunk's a trunk.
Military hardening guides and STIGs apply to system configuration - like, is your Linux really locked down extra tight.
Presumably DoD or any security conscious customer would want a dedicated trunking service - whether that's a PRI from AT&T or an MPLS circuit from AT&T for a dedicated SIP trunk.
I mean, the ultimate goal is to get to the PSTN unencrypted - so there's only so much that can tie around that!
If its for that other UC system you were working on, you'll be sad to know you're not allowed AADS according to military hardening
The only feature from a VOIP perspective I can think of that would be of any value is V.150. It's like T38, but for inband modem negotiation to encrypt audio. Newer G450 DSPs have it. Just like T38 between 2 WAN separated G450s with fax machines, V.150 does the same but for that in-band negotiation. I suppose a carrier COULD support it, but I've never heard of it. As long as it's G711 through them, that's the probably where that would end. It would be too complicated for a carrier to do. They'd just tell the people who wanted to use it to make it work on G711, or, yknow, if you want to have private phone calls, don't use the PSTN.
