D.3.2 Header layout for NetworkMessages
A UADP NetworkMessage header shall consist of the following fields according to this header layout:
Version / Flags
ExtendedFlags1
PublisherId
DataSetClassId
Additional restrictions:
The datatype for the PublisherId shall be UInt64
The NetworkMessage header layout is shown in Figure D.2.

Table D.5 shows the configuration for the NetworkMessage header.
| Name | Type | Restrictions |
| UADPVersion | Bit[0-3] | The version shall be 1 |
| UADPFlags | Bit[4-7] | Bit 4: PublisherId enabled = 1 Bit 5: GroupHeader enabled = 0 Bit 6: PayloadHeader enabled = 0 Bit 7: ExtendedFlags1 enabled = 1 |
| ExtendedFlags1 | Byte | Bit range 0-2: PublisherId Type 011 The PublisherId is of DataType UInt64 Bit 3: DataSetClassId enabled = 1 Bit 4: SecurityHeader enabled configurable (default=1) Bit 5: Timestamp enabled = 0 Bit 6: PicoSeconds enabled = 0 Bit 7: ExtendedFlags2 enabled = 0 |
| PublisherId | UInt64 | Configured value for the PubSubConnection. The datatype shall be UInt64. |
| DataSetClassId | Guid | The DataSetClassId associated with the DataSets in the NetworkMessage. All DataSetMessages in the NetworkMessage shall have the same DataSetClassId. – It shall be 65880051-7e5b-4a96-ae47-e0ef4704b924 |