diff --git a/include/osmocom/gsm/i460_mux.h b/include/osmocom/gsm/i460_mux.h
index 770b1e1..7c2f4af 100644
--- a/include/osmocom/gsm/i460_mux.h
+++ b/include/osmocom/gsm/i460_mux.h
@@ -1,116 +1,2 @@
-/*! \file i460_mux.h
- * ITU-T I.460 sub-channel multiplexer + demultiplexer */
-/*
- * (C) 2020 by Harald Welte <laforge@gnumonks.org>
- *
- * SPDX-License-Identifier: GPL-2.0+
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- */
-
 #pragma once
-#include <stdint.h>
-#include <osmocom/core/bits.h>
-#include <osmocom/core/linuxlist.h>
-#include <osmocom/core/msgb.h>
-
-/* I.460 sub-slot rate */
-enum osmo_i460_rate {
-	OSMO_I460_RATE_NONE,		/* disabled */
-	OSMO_I460_RATE_64k,
-	OSMO_I460_RATE_32k,
-	OSMO_I460_RATE_16k,
-	OSMO_I460_RATE_8k,
-};
-
-struct osmo_i460_subchan;
-
-typedef void (*out_cb_bits_t)(struct osmo_i460_subchan *schan, void *user_data,
-			      const ubit_t *bits, unsigned int num_bits);
-typedef void (*out_cb_bytes_t)(struct osmo_i460_subchan *schan, void *user_data,
-			       const uint8_t *bytes, unsigned int num_bytes);
-
-struct osmo_i460_subchan_demux {
-	/*! bit-buffer for output bits */
-	uint8_t *out_bitbuf;
-	/*! size of out_bitbuf in bytes */
-	unsigned int out_bitbuf_size;
-	/*! offset of next bit to be written in out_bitbuf */
-	unsigned int out_idx;
-	/*! callback to be called once we have received out_bitbuf_size bits */
-	out_cb_bits_t out_cb_bits;
-	out_cb_bytes_t out_cb_bytes;
-	void *user_data;
-};
-
-typedef void (*in_cb_queue_empty_t)(struct osmo_i460_subchan *schan, void *user_data);
-
-struct osmo_i460_subchan_mux {
-	/*! list of to-be-transmitted message buffers */
-	struct llist_head tx_queue;
-	in_cb_queue_empty_t in_cb_queue_empty;
-	void *user_data;
-};
-
-struct osmo_i460_subchan {
-	struct osmo_i460_timeslot *ts;	/* back-pointer */
-	enum osmo_i460_rate rate;		/* 8/16/32/64k */
-	uint8_t bit_offset;		/* bit offset inside each byte of the B-channel */
-	struct osmo_i460_subchan_demux demux;
-	struct osmo_i460_subchan_mux mux;
-};
-
-struct osmo_i460_timeslot {
-	struct osmo_i460_subchan schan[8];
-};
-
-/*! description of a sub-channel; passed by caller */
-struct osmo_i460_schan_desc {
-	enum osmo_i460_rate rate;
-	uint8_t bit_offset;
-	struct {
-		/* size (in bits) of the internal buffer; determines granularity */
-		size_t num_bits;
-		/*! call-back function called whenever we received num_bits */
-		out_cb_bits_t out_cb_bits;
-		/*! out_cb_bytes call-back function called whenever we received num_bits.
-		 * The user is usually expected to provide either out_cb_bits or out_cb_bytes.  If only
-		 * out_cb_bits is provided, output data will always be provided as unpacked bits;  if only
-		 * out_cb_bytes is provided, output data will always be provided as packet bits (bytes).  If
-		 * both are provided, it is up to the I.460 multiplex to decide if it calls either of the two,
-		 * depending on what can be provided without extra conversion. */
-		out_cb_bytes_t out_cb_bytes;
-		/* opaque user data pointer to pass to out_cb */
-		void *user_data;
-	} demux;
-
-	struct {
-		/* call-back function whenever the muxer requires more input data from the sub-channels,
-		 * but has nothing enqueued yet. A typical function would then call osmo_i460_mux_enqueue() */
-		in_cb_queue_empty_t in_cb_queue_empty;
-		/* opaque user data pointer to pass to in_cb */
-		void *user_data;
-	} mux;
-};
-
-void osmo_i460_demux_in(struct osmo_i460_timeslot *ts, const uint8_t *data, size_t data_len);
-
-void osmo_i460_mux_enqueue(struct osmo_i460_subchan *schan, struct msgb *msg);
-int osmo_i460_mux_out(struct osmo_i460_timeslot *ts, uint8_t *out, size_t out_len);
-
-void osmo_i460_ts_init(struct osmo_i460_timeslot *ts);
-
-struct osmo_i460_subchan *
-osmo_i460_subchan_add(void *ctx, struct osmo_i460_timeslot *ts, const struct osmo_i460_schan_desc *chd);
-
-void osmo_i460_subchan_del(struct osmo_i460_subchan *schan);
-
-/*! @} */
+#include <osmocom/isdn/i460_mux.h>