3GPP 24.501 v20.0.0 — the document's own text
8.2.28.1 Message definition
Taught in 7. What a NAS message looks like on the wire (CT1 — the group that writes what your phone says, in depth), 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
This message is sent by the UE or the network to transfer a plain 5GS NAS message as specified in clause 8.2 together with the sequence number and the message authentication code protecting the message. See table 8.2.28.1.1.
Message type: SECURITY PROTECTED 5GS NAS MESSAGE
Significance: dual
Direction: both
Table 8.2.28.1.1: SECURITY PROTECTED 5GS NAS MESSAGE message content
| IEI | Information Element | Type/Reference | Presence | Format | Length |
|---|---|---|---|---|---|
| Extended protocol discriminator | Extended protocol discriminator9.2 | M | V | 1 | |
| Security header type | Security header type9.3 | M | V | 1/2 | |
| Spare half octet | Spare half octet9.5 | M | V | 1/2 | |
| Message authentication code | Message authentication code9.8 | M | V | 4 | |
| Sequence number | Sequence number9.10 | M | V | 1 | |
| Plain 5GS NAS message | Plain 5GS NAS message9.9 | M | V | 3-n |
NOTE: The minimum length of Plain 5GS NAS message IE can be 2 octets if it includes a Test Mode Control message specified in 3GPP TS 38.509 [31AA].