9.2 Extended protocol discriminator

24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 18Stage 3TS

Bits 1 to 8 of the first octet of every 5GS NAS message contain the Extended protocol discriminator (EPD) IE. The EPD and its use are defined in 3GPP TS 24.007 [11]. The extended protocol discriminator in the header (see 3GPP TS 24.007 [11]) of a security protected 5GS NAS message is encoded as "5GS mobility management messages".