H.2 Signalling of ingress time for time synchronization

The ingress timestamp (TSi) of the PTP event (e.g. Sync) message is provided from the ingress TT (NW-TT/UPF or DS-TT/UE) to the egress TT, if supported in the PTP messages as described in clauses 5.27.1.2.2.1 and 5.27.1.2.2.2 using the Suffix field defined in clause 13.4 of IEEE Std 1588 [126]. The structure of the Suffix field follows the recommendation of clause 14.3 of IEEE Std 1588 [126], with an organizationId specific to 3GPP, an organizationSubType referring to an ingress timestamp and data field that carries the ingress timestamp encoded as specified in clause 5.3.3 of IEEE Std 1588 [126]. TS 24.535 [117] specifies the coding of the ingress timestamp in the (g)PTP messages between a DS-TT and a NW-TT.