I reviewed the document "Delay-Tolerant Networking TCP Convergence Layer Protocol Version 4 (draft-ietf-dtn-tcpclv4-15) as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the operational area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Intended status: Standards Track Current IESG state: In Last Call (ends 2019-11-06) IANA State: IANA - Review Needed Summary: The document describes a revised protocol for the TCP-based convergence layer (TCPCL) for Delay-Tolerant Networking (DTN). The protocol revision is based on implementation issues in the original TCPCL Version 3 of RFC7242 and updates to the Bundle Protocol contents, encodings, and convergence layer requirements in Bundle Protocol Version 7. There are nits in the document: ** Obsolete normative reference: RFC 5246 (Obsoleted by RFC 8446) == Outdated reference: A later version (-17) exists of draft-ietf-dtn-bpbis-14 As far as I can see the document does not cause any issues related to operations and management. The document can be published. Mehmet