Original text:
concepts presents the Transport Services architecture diagram and defines the concepts that are used by both the API and implementation documents.  The Preconnection allows applications <del> to configure Connection Properties, and the Connection represents an object that can be used to send and receive Messages. </del>  <del> A Connection is an abstraction that represents the communication. If the transport services interface selects a protocol such as TCP for the communication, a Connection will correspond to an underlying protocol connection.  If however a protocol such as UDP is selected, the Connection remains an abstraction at the end points. </del>  1.3. Connection: A Connection object represents one or more active transport protocol instances that can send and/or receive Messages <del> between local and remote systems.  It holds state pertaining to the underlying transport protocol instances and any ongoing data transfers.  This represents, for example, an active Connection in a connection-oriented protocol such as TCP, or a fully-specified 5-tuple for a connectionless protocol such as UDP.  It can also represent a pool of transport protocol instances, e.g., a set of TCP and QUIC connections to equivalent endpoints, or a stream of a multi-streaming transport protocol instance.  Connections can be created from a Preconnection or by a Listener. </del>  Listener: A Listener object accepts incoming transport protocol connections from remote systems and generates corresponding

Reviewer comments:
Trying to with a hint upfront that connections can be UDP, TCP or any other transport protocol instance... and then later explain about a connection that can remain an abstraction at the end points for a UDP example.
The last bullet in the Overview is out of place - the others are an overview of the document, but this one is a description of a concept.

Revised text:
concepts presents the Transport Services architecture diagram and defines the concepts that are used by both the API and implementation documents.  The Preconnection allows applications  <ins> to configure Connection Properties. </ins>  <ins> concepts also presents how an abstract Connection is used to select a transport protocol instance such as TCP, UDP, or another transport.  The Connection represents an object that can be used to send and receive Messages. </ins> 1.3. Connection: A Connection object represents one or more active transport protocol instances that can send and/or receive Messages  <ins> between local and remote systems.  It is an abstraction that represents the communication.  The Connection object holds state pertaining to the underlying transport protocol instances and any ongoing data transfers.  For example, an active Connection can represent a connection-oriented protocol such as TCP, or can represent a fully-specified 5-tuple for a connectionless protocol such as UDP, where the Connection remains an abstraction at the end points.  It can also represent a pool of transport protocol instances, e.g., a set of TCP and QUIC connections to equivalent endpoints, or a stream of a multi-streaming transport protocol instance.  Connections can be created from a Preconnection or by a Listener. </ins> Listener: A Listener object accepts incoming transport protocol connections from remote systems and generates corresponding