ACP allows negotiation for specific levels of accuracy and precision. Although an interva may be written in terms of nanoseconds, clients and servers may understand that less accuracy or precision may be expected. Absolute times may be specified in terms of any of several clocks. Network Delays ACP does not measure or allow for network delays. ACP allows for messages to be time- stamped, giving enough information to clients to permit adjustment for these factors.
All messages use a common format.
Each message consists of zero or more tagged fields. A tagged field contains of a tag followed by data. The tag determines the form and meaning of its associated data item. One type of tag specifies a request identifier , which identifies a specific request which is being made or which has been made by a client to a server. The client assigns half of the request identifier when the request is made, and the server assigns the second half when responding.