This Recommendation describes a method for bonding of multiple digital subscriber lines (DSL) using Time-Division Inverse Multiplexing (TDIM). This Recommendation provides a specification of the TDIM protocol in sufficient detail, to allow development and testing of interoperable implementations for both transmitter and receiver. It includes a multi-pair synchronization frame format, Bonding Communication Channel (BCC), byte-oriented dispatching, hitless addition and removal of pairs, fast removal of pair upon pair failure, using IEEE 802.3ah handshake for pair discovery, parameter negotiation and setup, and an optional FEC and interleaver.