Log in to the LMT. Then choose Configuration > Browse Configuration Data > Browse Site Data > Browse HDLC Path Data. View the HDLC types. If the types are PIU-PIU and TMU-PIU, the opposite slot number is the number of the slot for the board where the HDLC is configured. If the HDLC type is PTU-TMU, then run the MML command to query the HDLC status.