In the Precision Time Protocol (PTP), the message type is indicated by the value of the Message Type field in the PTP message header.

The Message Type field is a 1-byte (8-bit) field that identifies the type of message being sent or received. There are several defined message types in PTP, including:

• Sync (0x0): used to synchronize the clocks of the PTP devices
• Delay_Req (0x1): used to request the propagation delay between two PTP devices
• Pdelay_Req (0x2): used to request the propagation delay between a PTP grandmaster clock and a PTP peer clock
• Pdelay_Resp (0x3): used to respond to a Pdelay_Req message
• Follow_Up (0x8): used to provide a more precise timestamp for a Sync or Delay_Req message
• Announce (0xA): used to announce the presence of a PTP grandmaster clock on the network
• Signaling (0xB): used for various control functions

To find out the message type in a PTP message, you can examine the value of the Message Type field in the message header. This value will correspond to one of the defined message types in PTP.