RKF Engineering Solutions, LLC University of California, Berkeley Aalto University This document describes a TCP-based convergence layer (TCPCL) for Delay-Tolerant Networking (DTN). This version of the TCPCL protocol is based on implementation issues in the earlier TCPCL Version 3 of RFC7242 and updates to the Bundle Protocol (BP) contents, encodings, and convergence layer requirements in BP Version 7. Specifically, the TCPCLv4 uses CBOR-encoded BPv7 bundles as its service data unit being transported and provides a reliable transport of such bundles.