Symptom:
When IPv6 only endpoints make a call over a DO-ANAT-SIP trunk with IPv6 addressing preferred on the SIP trunk to another IPv6 only phone,  and hold is initiated, if the call fails to allocate an MOH/ANN resource, the call gets disconnected in both directions with reorder.

Conditions:
CUCM Image: 10.0.1.10000-15

Topology:

Phone-A(V6)---(CM)------(SIP-DO-ANAT-V4V6-Trunk)---------(SME)--------(SIP-DO-ANAT-V4V6-Trunk)--------(CM)---Phone-B(V6)


Phone-A (Single STack V6) makes call over SME using SIP-DO-ANAT enable V6V4 (V6 Prefer) to Phone-B (Single Stack V6)
--- Voice Path Established ----
Phone-A Put Call on Hold.
Phone-A Resume Call.
Phone-A gets reorder.
Phone--B gets reorder.