3.2.1 Abstract Data Model

This section describes a conceptual model of possible data organization that an implementation maintains to participate in this protocol. The described organization is provided to facilitate the explanation of how the protocol behaves. This document does not mandate that implementations adhere to this model as long as their external behavior is consistent with that described in this document.

User agents are responsible for generating epid parameter values in accordance with requirements in section 3.2.3.1; however, the exact mechanism is outside the scope of this protocol. To create a value for an epid parameter, the user agent SHOULD use a hexadecimal string no more than 16 hexadecimal characters long. A 64-bit random number or the 8-byte Media Access Control (MAC) address of the local network interface card can be encoded as a 16-character hexadecimal string to form a value for an epid parameter.