As a reminder, the NSI Connection Service document v 2.1 is in public comment until October 30 2018 in the OGF Redmine Editor public comments page, or directly at https://redmine.ogf.org/boards/41/topics/500 This document describes the Connection Service v2.1, which is one of a suite of services that make up the Network Service Interface (NSI). The NSI is a web-service based protocol that operates between a requester software agent and a provider software agent. The full suite of NSI services allows an application or network provider to request and manage circuit service instances. Apart from the Connection Service, this includes the Document Distribution Service, which allows NSI documents such as the NSI Topology and the NSA Description to be shared among participating NSI agents. The complete set of NSI services is described in the Network Services Framework v2.0. This Connection Service document describes the protocol, state machine, architecture and associated processes and environment in which software agents interact to deliver a Connection. A Connection is a point-to-point network circuit that can transit multiple networks belonging to different providers. Comments from the community would be helpful, even to note that the document is complete and well formed. (Of course, more substantial and critical comments are also welcome).