Test objective "IUT successfully processes all mandatory AVPs in a RT-Request received due to S-CSCF network de-registration notification procedure and sends RT-Answer."
Reference
"TS 129 228 (V15.1.0) [4], clause 6.1.3",
"TS 129 229 (V15.0.0) [5], clauses 6.1.9 and 6.1.10"