Value,Description,Reference
0,Reserved,[RFC8169]
1,No payload,[RFC8169]
2,"PTPv2, Ethernet encapsulation",[RFC8169]
3,"PTPv2, IPv4 encapsulation",[RFC8169]
4,"PTPv2, IPv6 encapsulation",[RFC8169]
5,NTP,[RFC8169]
6-191,Unassigned,
192-254,Reserved for Private Use,[RFC8169]
255,Reserved,[RFC8169]