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.

TotalBlocks: Specifies the number of blocks in the content. This value is provided by the WDS Multicast Session Initiation Protocol [MS-WDSMSI].

MissingBlocksBitmap: An array of bits where the size of the array is set to the value of TotalBlocks. Each bit in the array is initialized to 0. When a DATA packet (section 2.2.4) is received for a specified block number, the bit at that index is changed to 1. The array uses a 1-based index.

BlockSize: Specifies the number of bytes of content data sent in each DATA packet. This value is provided by the WDS Multicast Session Initiation Protocol.

MaxCacheSize: Specifies the maximum number of bytes of DATA packets that can be processed by a client before the WDS Multicast Transport Protocol [MS-WDSMT] stops sending the DATA trigger, and the protocol MUST wait for a Cache Done trigger from the WDS Multicast Application Protocol. The default maximum number of bytes is 2097152.

JoinTime:  MUST be set to local time (in seconds) on initialization.