ISO/IEC 14476-1:2002 情報技術—強化された通信トランスポートプロトコル：シンプレックスマルチキャストトランスポートの仕様—パート1： | ページ 6

3.3.1

application

Represents an Internet multicast application in this Specification. It corresponds to a transport service user in the OSI mode. It exchanges transport service primitives with the corresponding transport protocol entity. In the Internet, it communicates with the transport protocol entity via a socket interface.

3.3.2

packet

Represents a unit of transport data, which is equivalent to a segment in TCP/IP and a transport protocol data unit (TPDU) in OSI model. A transport entity communicates with another transport entity by transmitting packets. A transport protocol entity creates a packet, which is encapsulated into an IP datagram and then delivered to the destination entity over networks.

3.3.3

sender

Represents a transport protocol entity that sends the multicast data to the receivers.

3.3.4

receiver

Represents a transport protocol entity that receives the multicast data.

3.3.5

tree

Is a hierarchical logical tree employed for providing scalable reliability control. A tree defines a parent-child relationship between a pair of tree nodes. Sender and receivers are organized into a tree. In the tree hierarchy, a tree node is designated as TO (Top Owner), LO (Local Owner) or LE (Leaf Entity). TO is a single ECTP sender. All the receivers are designated as LOs or LEs.

3.3.6

TO (top owner)

Is a single sender in the ECTP simplex multicast connection. TO is the root of the tree and manages the overall protocol operations for the connection.

3.3.7

LO (local owner)

Is a receiver that manages a local group. An LO is responsible for the overall protocol operations for its local group defined by the control tree. For error recovery, it retransmits the multicast data that have been lost by its children. For flow and congestion control, it aggregates the control information for all of its children and then delivers the aggregated information toward TO. In terms of the reliability control operations, TO is also an LO.

3.3.8

LE (leaf entity)

Is a receiver that has not been designated as an LO. An LE cannot have any children. It is located as a leaf node on the tree.

3.3.9

local group

Consists of a parent and its children in the tree hierarchy.

3.3.10

parent

Is a parent node for a local group. TO or an LO can be a parent.

3.3.11

child

Is a child node for a local group. An LO or LE can be a child.