diff --git a/include/osmocom/isdn/Makefile.am b/include/osmocom/isdn/Makefile.am
index bf33623ad..ad2d8dd5b 100644
--- a/include/osmocom/isdn/Makefile.am
+++ b/include/osmocom/isdn/Makefile.am
@@ -1,6 +1,7 @@
 osmoisdn_HEADERS = \
 	i460_mux.h \
 	lapd_core.h \
+	v110.h \
 	$(NULL)
 
 osmoisdndir = $(includedir)/osmocom/isdn
diff --git a/include/osmocom/isdn/v110.h b/include/osmocom/isdn/v110.h
new file mode 100644
index 000000000..4c1214c34
--- /dev/null
+++ b/include/osmocom/isdn/v110.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include <osmocom/core/bits.h>
+
+/* See Section 5.1.2.1 of ITU-T V.110 */
+#define MAX_D_BITS	48
+#define MAX_E_BITS	7
+#define MAX_S_BITS	9
+#define MAX_X_BITS	2
+
+/*! a 'decoded' representation of a single V.110 frame. contains unpacket D, E, S and X bits */
+struct osmo_v110_decoded_frame {
+	ubit_t d_bits[MAX_D_BITS];
+	ubit_t e_bits[MAX_E_BITS];
+	ubit_t s_bits[MAX_S_BITS];
+	ubit_t x_bits[MAX_X_BITS];
+};
+
+int osmo_v110_decode_frame(struct osmo_v110_decoded_frame *fr, const ubit_t *ra_bits, size_t n_bits);
+int osmo_v110_encode_frame(ubit_t *ra_bits, size_t n_bits, const struct osmo_v110_decoded_frame *fr);
+
+void osmo_v110_ubit_dump(FILE *outf, const ubit_t *fr, size_t in_len);
+
+
+/*! enum for each supported V.110 synchronous RA1 function (one for each user bitrate) */
+enum osmo_v100_sync_ra1_rate {
+	OSMO_V110_SYNC_RA1_600,
+	OSMO_V110_SYNC_RA1_1200,
+	OSMO_V110_SYNC_RA1_2400,
+	OSMO_V110_SYNC_RA1_4800,
+	OSMO_V110_SYNC_RA1_7200,
+	OSMO_V110_SYNC_RA1_9600,
+	OSMO_V110_SYNC_RA1_12000,
+	OSMO_V110_SYNC_RA1_14400,
+	OSMO_V110_SYNC_RA1_19200,
+	OSMO_V110_SYNC_RA1_24000,
+	OSMO_V110_SYNC_RA1_28800,
+	OSMO_V110_SYNC_RA1_38400,
+	_NUM_OSMO_V110_SYNC_RA1
+};
+
+int osmo_v110_sync_ra1_get_user_data_chunk_bitlen(enum osmo_v100_sync_ra1_rate rate);
+int osmo_v110_sync_ra1_get_user_data_rate(enum osmo_v100_sync_ra1_rate rate);
+int osmo_v110_sync_ra1_get_intermediate_rate(enum osmo_v100_sync_ra1_rate rate);
+
+int osmo_v110_sync_ra1_user_to_ir(enum osmo_v100_sync_ra1_rate rate, struct osmo_v110_decoded_frame *fr,
+				  const ubit_t *d_in, size_t in_len);
+
+int osmo_v110_sync_ra1_ir_to_user(enum osmo_v100_sync_ra1_rate rate, ubit_t *d_out, size_t out_len,
+				  const struct osmo_v110_decoded_frame *fr);
diff --git a/src/isdn/Makefile.am b/src/isdn/Makefile.am
index 2aed0bf73..3bb7b047b 100644
--- a/src/isdn/Makefile.am
+++ b/src/isdn/Makefile.am
@@ -13,7 +13,7 @@ endif
 noinst_LTLIBRARIES = libisdnint.la
 lib_LTLIBRARIES = libosmoisdn.la
 
-libisdnint_la_SOURCES = i460_mux.c lapd_core.c
+libisdnint_la_SOURCES = i460_mux.c lapd_core.c v110.c
 
 libisdnint_la_LDFLAGS = -no-undefined
 libisdnint_la_LIBADD = $(top_builddir)/src/core/libosmocore.la
diff --git a/src/isdn/libosmoisdn.map b/src/isdn/libosmoisdn.map
index 5ac65c908..3269771cc 100644
--- a/src/isdn/libosmoisdn.map
+++ b/src/isdn/libosmoisdn.map
@@ -21,5 +21,14 @@ osmo_i460_subchan_del;
 osmo_i460_subchan_count;
 osmo_i460_ts_init;
 
+osmo_v110_decode_frame;
+osmo_v110_encode_frame;
+osmo_v110_ubit_dump;
+osmo_v110_sync_ra1_get_user_data_chunk_bitlen;
+osmo_v110_sync_ra1_get_user_data_rate;
+osmo_v110_sync_ra1_get_intermediate_rate;
+osmo_v110_sync_ra1_user_to_ir;
+osmo_v110_sync_ra1_ir_to_user;
+
 local: *;
 };
diff --git a/src/isdn/v110.c b/src/isdn/v110.c
new file mode 100644
index 000000000..4d1354783
--- /dev/null
+++ b/src/isdn/v110.c
@@ -0,0 +1,582 @@
+/* V.110 frames according to ITU-T V.110
+ *
+ * This code implements the following functionality:
+ * - parsing/encoding of osmo_v110_decoded_frame from/to actual 80-bit V.110 frame
+ * - synchronous rate adapting of user bit rate to V.110 D-bits as per Table 6
+ *
+ * It is (at least initially) a very "naive" implementation, as it first and foremost
+ * aims to be functional and correct, rather than efficient in any way.  Hence it
+ * operates on unpacked bits (ubit_t, 1 bit per byte), and has various intermediate
+ * representations and indirect function calls.  If needed, a more optimized variant
+ * can always be developed later on.
+ */
+
+/* (C) 2022 by Harald Welte <laforge@osmocom.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.
+ */
+
+#include <stdint.h>
+#include <errno.h>
+
+#include <osmocom/core/bits.h>
+
+#include <osmocom/isdn/v110.h>
+
+/*************************************************************************
+ * V.110 frame decoding/encoding (ubits <-> struct with D/S/X/E bits)
+ *************************************************************************/
+
+/*! Decode a 80-bit V.110 frame present as 80 ubits into a struct osmo_v110_decoded_frame.
+ *  \param[out] fr caller-allocated output data structure, filled by this function
+ *  \param[in] ra_bits One V.110 frame as 80 unpacked bits.
+ *  \param[in] n_bits number of unpacked bits provided in ra_bits
+ *  \returns 0 in case of success; negative on error. */
+int osmo_v110_decode_frame(struct osmo_v110_decoded_frame *fr, const ubit_t *ra_bits, size_t n_bits)
+{
+	if (n_bits < 80)
+		return -EINVAL;
+
+	/* X1 .. X2 */
+	fr->x_bits[0] = ra_bits[2 * 8 + 7];
+	fr->x_bits[1] = ra_bits[7 * 8 + 7];
+
+	/* S1, S3, S4, S6, S8, S9 */
+	fr->s_bits[0] = ra_bits[1 * 8 + 7];
+	fr->s_bits[2] = ra_bits[3 * 8 + 7];
+	fr->s_bits[3] = ra_bits[4 * 8 + 7];
+	fr->s_bits[5] = ra_bits[6 * 8 + 7];
+	fr->s_bits[7] = ra_bits[8 * 8 + 7];
+	fr->s_bits[8] = ra_bits[9 * 8 + 7];
+
+	/* E1 .. E7 */
+	memcpy(fr->e_bits, ra_bits + 5 * 8 + 1, 7);
+
+	/* D-bits */
+	memcpy(fr->d_bits + 0 * 6, ra_bits + 1 * 8 + 1, 6);
+	memcpy(fr->d_bits + 1 * 6, ra_bits + 2 * 8 + 1, 6);
+	memcpy(fr->d_bits + 2 * 6, ra_bits + 3 * 8 + 1, 6);
+	memcpy(fr->d_bits + 3 * 6, ra_bits + 4 * 8 + 1, 6);
+
+	memcpy(fr->d_bits + 4 * 6, ra_bits + 6 * 8 + 1, 6);
+	memcpy(fr->d_bits + 5 * 6, ra_bits + 7 * 8 + 1, 6);
+	memcpy(fr->d_bits + 6 * 6, ra_bits + 8 * 8 + 1, 6);
+	memcpy(fr->d_bits + 7 * 6, ra_bits + 9 * 8 + 1, 6);
+
+	return 0;
+}
+
+/*! Encode a struct osmo_v110_decoded_frame into an 80-bit V.110 frame as ubits.
+ *  \param[out] ra_bits caller-provided output buffer at leat 80 ubits large
+ *  \param[in] n_bits length of ra_bits. Must be at least 80.
+ *  \param[in] input data structure
+ *  \returns number of bits written to ra_bits */
+int osmo_v110_encode_frame(ubit_t *ra_bits, size_t n_bits, const struct osmo_v110_decoded_frame *fr)
+{
+	if (n_bits < 80)
+		return -ENOSPC;
+
+	/* alignment pattern */
+	memset(ra_bits+0, 0, 8);
+	for (int i = 1; i < 10; i++)
+		ra_bits[i*8] = 1;
+
+	/* X1 .. X2 */
+	ra_bits[2 * 8 + 7] = fr->x_bits[0];
+	ra_bits[7 * 8 + 7] = fr->x_bits[1];
+
+	/* S1, S3, S4, S6, S8, S9 */
+	ra_bits[1 * 8 + 7] = fr->s_bits[0];
+	ra_bits[3 * 8 + 7] = fr->s_bits[2];
+	ra_bits[4 * 8 + 7] = fr->s_bits[3];
+	ra_bits[6 * 8 + 7] = fr->s_bits[5];
+	ra_bits[8 * 8 + 7] = fr->s_bits[7];
+	ra_bits[9 * 8 + 7] = fr->s_bits[8];
+
+	/* E1 .. E7 */
+	memcpy(ra_bits + 5 * 8 + 1, fr->e_bits, 7);
+
+	/* D-bits */
+	memcpy(ra_bits + 1 * 8 + 1, fr->d_bits + 0 * 6, 6);
+	memcpy(ra_bits + 2 * 8 + 1, fr->d_bits + 1 * 6, 6);
+	memcpy(ra_bits + 3 * 8 + 1, fr->d_bits + 2 * 6, 6);
+	memcpy(ra_bits + 4 * 8 + 1, fr->d_bits + 3 * 6, 6);
+
+	memcpy(ra_bits + 6 * 8 + 1, fr->d_bits + 4 * 6, 6);
+	memcpy(ra_bits + 7 * 8 + 1, fr->d_bits + 5 * 6, 6);
+	memcpy(ra_bits + 8 * 8 + 1, fr->d_bits + 6 * 6, 6);
+	memcpy(ra_bits + 9 * 8 + 1, fr->d_bits + 7 * 6, 6);
+
+	return 10 * 8;
+}
+
+/*! Print a encoded V.110 frame in the same table-like structure as the spec.
+ *  \param outf output FILE stream to which to dump
+ *  \param[in] fr unpacked bits to dump
+ *  \param[in] in_len length of unpacked bits available at fr. */
+void osmo_v110_ubit_dump(FILE *outf, const ubit_t *fr, size_t in_len)
+{
+	if (in_len < 80)
+		fprintf(outf, "short input data\n");
+
+	for (unsigned int octet = 0; octet < 10; octet++) {
+		fprintf(outf, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
+			fr[octet * 8 + 0], fr[octet * 8 + 1], fr[octet * 8 + 2], fr[octet * 8 + 3],
+			fr[octet * 8 + 4], fr[octet * 8 + 5], fr[octet * 8 + 6], fr[octet * 8 + 7]);
+	}
+}
+
+/*************************************************************************
+ * RA1 synchronous rate adaptation
+ *************************************************************************/
+
+/* I actually couldn't find any reference as to the value of F(ill) bits */
+#define F 1
+
+/*! Adapt from 6 synchronous 600bit/s input bits to a decoded V.110 frame.
+ *  \param[out] fr caller-allocated output frame to which E+D bits are stored
+ *  \param[in] d_in input user bits
+ *  \param[in] in_len number of bits in d_in. Must be 6.
+ *  \returns 0 on success; negative in case of error. */
+static int v110_adapt_600_to_IR8000(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+	if (in_len != 6)
+		return -EINVAL;
+
+	/* Table 6a / V.110 */
+	fr->e_bits[0] = 1;
+	fr->e_bits[1] = 0;
+	fr->e_bits[2] = 0;
+	for (int i = 0; i < 6; i++)
+		memset(fr->d_bits + i*8, d_in[i], 8);
+
+	return 0;
+}
+
+static int v110_adapt_IR8000_to_600(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+	if (out_len < 6)
+		return -ENOSPC;
+
+	if (fr->e_bits[0] != 1 || fr->e_bits[1] != 0 || fr->e_bits[2] != 0)
+		return -EINVAL;
+
+	for (int i = 0; i < 6; i++) {
+		/* we only use one of the bits, not some kind of consistency check or majority vote */
+		d_out[i] = fr->d_bits[i*8];
+	}
+
+	return 6;
+}
+
+/*! Adapt from 12 synchronous 1200bit/s input bits to a decoded V.110 frame.
+ *  \param[out] fr caller-allocated output frame to which E+D bits are stored
+ *  \param[in] d_in input user bits
+ *  \param[in] in_len number of bits in d_in. Must be 12.
+ *  \returns 0 on success; negative in case of error. */
+static int v110_adapt_1200_to_IR8000(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+	if (in_len != 12)
+		return -EINVAL;
+
+	/* Table 6b / V.110 */
+	fr->e_bits[0] = 0;
+	fr->e_bits[1] = 1;
+	fr->e_bits[2] = 0;
+	for (int i = 0; i < 12; i++)
+		memset(fr->d_bits + i*4, d_in[i], 4);
+
+	return 0;
+}
+
+static int v110_adapt_IR8000_to_1200(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+	if (out_len < 12)
+		return -ENOSPC;
+
+	if (fr->e_bits[0] != 0 || fr->e_bits[1] != 1 || fr->e_bits[2] != 0)
+		return -EINVAL;
+
+	for (int i = 0; i < 12; i++) {
+		/* we only use one of the bits, not some kind of consistency check or majority vote */
+		d_out[i] = fr->d_bits[i*4];
+	}
+
+	return 12;
+}
+
+/*! Adapt from 24 synchronous 2400bit/s input bits to a decoded V.110 frame.
+ *  \param[out] fr caller-allocated output frame to which E+D bits are stored
+ *  \param[in] d_in input user bits
+ *  \param[in] in_len number of bits in d_in. Must be 24.
+ *  \returns 0 on success; negative in case of error. */
+static int v110_adapt_2400_to_IR8000(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+	if (in_len != 24)
+		return -EINVAL;
+
+	/* Table 6c / V.110 */
+	fr->e_bits[0] = 1;
+	fr->e_bits[1] = 1;
+	fr->e_bits[2] = 0;
+	for (int i = 0; i < 24; i++) {
+		fr->d_bits[i*2 + 0] = d_in[i];
+		fr->d_bits[i*2 + 1] = d_in[i];
+	}
+
+	return 0;
+}
+
+static int v110_adapt_IR8000_to_2400(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+	if (out_len < 24)
+		return -ENOSPC;
+
+	if (fr->e_bits[1] != 1 || fr->e_bits[1] != 1 || fr->e_bits[2] != 0)
+		return -EINVAL;
+
+	for (int i = 0; i < 24; i++) {
+		/* we only use one of the bits, not some kind of consistency check or majority vote */
+		d_out[i] = fr->d_bits[i*2];
+	}
+
+	return 24;
+}
+
+/*! Adapt from 36 synchronous N x 3600bit/s input bits to a decoded V.110 frame.
+ *  \param[out] fr caller-allocated output frame to which E+D bits are stored
+ *  \param[in] d_in input user bits
+ *  \param[in] in_len number of bits in d_in. Must be 36.
+ *  \returns 0 on success; negative in case of error. */
+static int v110_adapt_Nx3600_to_IR(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+	int d_idx = 0;
+
+	if (in_len != 36)
+		return -EINVAL;
+
+	/* Table 6d / V.110 */
+	fr->e_bits[0] = 1;
+	fr->e_bits[1] = 0;
+	fr->e_bits[2] = 1;
+
+	memcpy(fr->d_bits + d_idx, d_in + 0, 10); d_idx += 10;	/* D1..D10 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 10, 2); d_idx += 2;	/* D11..D12 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 12, 2); d_idx += 2;	/* D13..D14 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 14, 14); d_idx += 14;	/* D15..D28 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 28, 2); d_idx += 2;	/* D29..D30 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 30, 2); d_idx += 2;	/* D31..D32 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 32, 4); d_idx += 4;	/* D33..D36 */
+
+	OSMO_ASSERT(d_idx == 48);
+
+	return 0;
+}
+
+static int v110_adapt_IR_to_Nx3600(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+	int d_idx = 0;
+
+	if (out_len < 36)
+		return -ENOSPC;
+
+	if (fr->e_bits[0] != 1 || fr->e_bits[1] != 0 || fr->e_bits[2] != 1)
+		return -EINVAL;
+
+	memcpy(d_out + 0, fr->d_bits + d_idx, 10); d_idx += 10;	/* D1..D10 */
+	d_idx += 2;
+	memcpy(d_out + 10, fr->d_bits + d_idx, 2); d_idx += 2;	/* D11..D12 */
+	d_idx += 2;
+	memcpy(d_out + 12, fr->d_bits + d_idx, 2); d_idx += 2;	/* D13..D14 */
+	d_idx += 2;
+	memcpy(d_out + 14, fr->d_bits + d_idx, 14); d_idx += 14;/* D15..D28 */
+	d_idx += 2;
+	memcpy(d_out + 28, fr->d_bits + d_idx, 2); d_idx += 2;	/* D29..D30 */
+	d_idx += 2;
+	memcpy(d_out + 30, fr->d_bits + d_idx, 2); d_idx += 2;	/* D31..D32 */
+	d_idx += 2;
+	memcpy(d_out + 32, fr->d_bits + d_idx, 4); d_idx += 4;	/* D33..D36 */
+
+	OSMO_ASSERT(d_idx == 48);
+
+	return 36;
+}
+
+
+/*! Adapt from 48 synchronous N x 4800bit/s input bits to a decoded V.110 frame.
+ *  \param[out] fr caller-allocated output frame to which E+D bits are stored
+ *  \param[in] d_in input user bits
+ *  \param[in] in_len number of bits in d_in. Must be 48.
+ *  \returns 0 on success; negative in case of error. */
+static int v110_adapt_Nx4800_to_IR(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+	if (in_len != 48)
+		return -EINVAL;
+
+	/* Table 6e / V.110 */
+	fr->e_bits[0] = 0;
+	fr->e_bits[1] = 1;
+	fr->e_bits[2] = 1;
+
+	memcpy(fr->d_bits, d_in, 48);
+
+	return 0;
+}
+
+static int v110_adapt_IR_to_Nx4800(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+	if (out_len < 48)
+		return -ENOSPC;
+
+	if (fr->e_bits[0] != 0 || fr->e_bits[1] != 1 || fr->e_bits[2] != 1)
+		return -EINVAL;
+
+	memcpy(d_out, fr->d_bits, 48);
+
+	return 48;
+}
+
+/*! Adapt from 30 synchronous N x 12000bit/s input bits to a decoded V.110 frame.
+ *  \param[out] fr caller-allocated output frame to which E+D bits are stored
+ *  \param[in] d_in input user bits
+ *  \param[in] in_len number of bits in d_in. Must be 30.
+ *  \returns 0 on success; negative in case of error. */
+static int v110_adapt_Nx12000_to_IR(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+	int d_idx = 0;
+
+	if (in_len != 30)
+		return -EINVAL;
+
+	/* Table 6f / V.110 */
+	fr->e_bits[0] = 0;
+	fr->e_bits[1] = 0;
+	fr->e_bits[2] = 1;
+
+	memcpy(fr->d_bits + d_idx, d_in + 0, 10); d_idx += 10;	/* D1..D10 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 10, 2); d_idx += 2;	/* D11..D12 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 12, 2); d_idx += 2;	/* D13..D14 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	fr->d_bits[d_idx++] = d_in[14];				/* D15 */
+	memset(fr->d_bits + d_idx, F, 3); d_idx += 3;
+	memcpy(fr->d_bits + d_idx, d_in + 15, 10); d_idx += 10;	/* D16..D25 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 25, 2); d_idx += 2;	/* D26..D27 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	memcpy(fr->d_bits + d_idx, d_in + 27, 2); d_idx += 2;	/* D28..D29 */
+	memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+	fr->d_bits[d_idx++] = d_in[29];				/* D30 */
+	memset(fr->d_bits + d_idx, F, 3); d_idx += 3;
+
+	OSMO_ASSERT(d_idx == 48);
+
+	return 0;
+}
+
+static int v110_adapt_IR_to_Nx12000(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+	int d_idx = 0;
+
+	if (out_len < 30)
+		return -ENOSPC;
+
+	if (fr->e_bits[0] != 0 || fr->e_bits[1] != 0 || fr->e_bits[2] != 1)
+		return -EINVAL;
+
+	memcpy(d_out + 0, fr->d_bits + d_idx, 10); d_idx += 10;	/* D1..D10 */
+	d_idx += 2;
+	memcpy(d_out + 10, fr->d_bits + d_idx, 2); d_idx += 2;	/* D11..D12 */
+	d_idx += 2;
+	memcpy(d_out + 12, fr->d_bits + d_idx, 2); d_idx += 2;	/* D13..D14 */
+	d_idx += 2;
+	d_out[14] = fr->d_bits[d_idx++];			/* D15 */
+	d_idx += 3;
+	memcpy(d_out + 15, fr->d_bits + d_idx, 10); d_idx += 10;/* D16..D25 */
+	d_idx += 2;
+	memcpy(d_out + 25, fr->d_bits + d_idx, 2); d_idx += 2;	/* D26..D27 */
+	d_idx += 2;
+	memcpy(d_out + 27, fr->d_bits + d_idx, 2); d_idx += 2;	/* D28..D29 */
+	d_idx += 2;
+	d_out[29] = fr->d_bits[d_idx++];			/* D30 */
+	d_idx += 3;
+
+	OSMO_ASSERT(d_idx == 48);
+
+	return 30;
+}
+
+/* definition of a synchronous V.110 RA1 rate adaptation. There is one for each supported tuple
+ * of user data rate and intermediate rate (IR). */
+struct osmo_v110_sync_ra1 {
+	unsigned int data_rate;
+	unsigned int intermediate_rate;
+	unsigned int user_data_chunk_bits;
+	/*! RA1 function in user bitrate -> intermediate rate direction */
+	int (*adapt_user_to_ir)(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len);
+	/*! RA1 function in intermediate rate -> user bitrate direction */
+	int (*adapt_ir_to_user)(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr);
+};
+
+/* all of the synchronous data signalling rates; see Table 1/V.110 */
+static const struct osmo_v110_sync_ra1 osmo_v110_sync_ra1_def[_NUM_OSMO_V110_SYNC_RA1] = {
+	[OSMO_V110_SYNC_RA1_600] = {
+		.data_rate = 600,
+		.intermediate_rate = 8000,
+		.user_data_chunk_bits = 6,
+		.adapt_user_to_ir = v110_adapt_600_to_IR8000,
+		.adapt_ir_to_user = v110_adapt_IR8000_to_600,
+	},
+	[OSMO_V110_SYNC_RA1_1200] = {
+		.data_rate = 1200,
+		.intermediate_rate = 8000,
+		.user_data_chunk_bits = 12,
+		.adapt_user_to_ir = v110_adapt_1200_to_IR8000,
+		.adapt_ir_to_user = v110_adapt_IR8000_to_1200,
+	},
+	[OSMO_V110_SYNC_RA1_2400] = {
+		.data_rate = 2400,
+		.intermediate_rate = 8000,
+		.user_data_chunk_bits = 24,
+		.adapt_user_to_ir = v110_adapt_2400_to_IR8000,
+		.adapt_ir_to_user = v110_adapt_IR8000_to_2400,
+	},
+	[OSMO_V110_SYNC_RA1_4800] = {
+		.data_rate = 4800,
+		.intermediate_rate = 8000,
+		.user_data_chunk_bits = 48,
+		.adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+	},
+	[OSMO_V110_SYNC_RA1_7200] = {
+		.data_rate = 7200,
+		.intermediate_rate = 16000,
+		.user_data_chunk_bits = 36,
+		.adapt_user_to_ir = v110_adapt_Nx3600_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx3600,
+	},
+	[OSMO_V110_SYNC_RA1_9600] = {
+		.data_rate = 9600,
+		.intermediate_rate = 16000,
+		.user_data_chunk_bits = 48,
+		.adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+	},
+	[OSMO_V110_SYNC_RA1_12000] = {
+		.data_rate = 12000,
+		.intermediate_rate = 32000,
+		.user_data_chunk_bits = 30,
+		.adapt_user_to_ir = v110_adapt_Nx12000_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx12000,
+	},
+	[OSMO_V110_SYNC_RA1_14400] = {
+		.data_rate = 14400,
+		.intermediate_rate = 32000,
+		.user_data_chunk_bits = 36,
+		.adapt_user_to_ir = v110_adapt_Nx3600_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx3600,
+	},
+	[OSMO_V110_SYNC_RA1_19200] = {
+		.data_rate = 19200,
+		.intermediate_rate = 32000,
+		.user_data_chunk_bits = 48,
+		.adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+	},
+	[OSMO_V110_SYNC_RA1_24000] = {
+		.data_rate = 24000,
+		.intermediate_rate = 64000,
+		.user_data_chunk_bits = 30,
+		.adapt_user_to_ir = v110_adapt_Nx12000_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx12000,
+	},
+	[OSMO_V110_SYNC_RA1_28800] = {
+		.data_rate = 28800,
+		.intermediate_rate = 64000,
+		.user_data_chunk_bits = 36,
+		.adapt_user_to_ir = v110_adapt_Nx3600_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx3600,
+	},
+	[OSMO_V110_SYNC_RA1_38400] = {
+		.data_rate = 38400,
+		.intermediate_rate = 64000,
+		.user_data_chunk_bits = 48,
+		.adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+		.adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+	},
+};
+
+/*! obtain the size (in number of bits) of the user data bits in one V.110
+ *  frame for specified RA1 rate */
+int osmo_v110_sync_ra1_get_user_data_chunk_bitlen(enum osmo_v100_sync_ra1_rate rate)
+{
+	if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+		return -EINVAL;
+
+	return osmo_v110_sync_ra1_def[rate].user_data_chunk_bits;
+}
+
+/*! obtain the user data rate (in bits/s) for specified RA1 rate */
+int osmo_v110_sync_ra1_get_user_data_rate(enum osmo_v100_sync_ra1_rate rate)
+{
+	if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+		return -EINVAL;
+
+	return osmo_v110_sync_ra1_def[rate].data_rate;
+}
+
+/*! obtain the intermediate rate (in bits/s) for specified RA1 rate */
+int osmo_v110_sync_ra1_get_intermediate_rate(enum osmo_v100_sync_ra1_rate rate)
+{
+	if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+		return -EINVAL;
+
+	return osmo_v110_sync_ra1_def[rate].intermediate_rate;
+}
+
+/*! perform V.110 RA1 function in user rate -> intermediate rate direction.
+ *  \param[in] rate specification of the user bitrate
+ *  \param[out] fr caller-allocated output buffer for the [decoded] V.110 frame generated
+ *  \param[in] d_in input user data (unpacked bits)
+ *  \param[in] in_len length of user input data (in number of bits)
+ *  \returns 0 on success; negative in case of error */
+int osmo_v110_sync_ra1_user_to_ir(enum osmo_v100_sync_ra1_rate rate, struct osmo_v110_decoded_frame *fr,
+				  const ubit_t *d_in, size_t in_len)
+{
+	if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+		return -EINVAL;
+
+	return osmo_v110_sync_ra1_def[rate].adapt_user_to_ir(fr, d_in, in_len);
+}
+
+/*! perform V.110 RA1 function in intermediate rate -> user rate direction.
+ *  \param[in] rate specification of the user bitrate
+ *  \param[out] d_out caller-allocated output user data (unpacked bits)
+ *  \param[out] out_len length of d_out output buffer
+ *  \param[in] fr [decoded] V.110 frame used as input
+ *  \returns number of unpacked bits written to d_out on success; negative in case of error */
+int osmo_v110_sync_ra1_ir_to_user(enum osmo_v100_sync_ra1_rate rate, ubit_t *d_out, size_t out_len,
+				  const struct osmo_v110_decoded_frame *fr)
+{
+	if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+		return -EINVAL;
+
+	return osmo_v110_sync_ra1_def[rate].adapt_ir_to_user(d_out, out_len, fr);
+}
diff --git a/tests/Makefile.am b/tests/Makefile.am
index eeefd3ed3..f0c80d52b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -50,6 +50,8 @@ check_PROGRAMS = timer/timer_test sms/sms_test ussd/ussd_test		\
 		 smscb/gsm0341_test                                     \
 		 smscb/cbsp_test                                        \
 		 auth/xor2g_test                                        \
+		 v110/test_frame                                        \
+		 v110/test_ra1                                          \
 		 $(NULL)
 
 if ENABLE_MSGFILE
@@ -339,6 +341,12 @@ time_cc_time_cc_test_LDADD = $(LDADD)
 iuup_iuup_test_SOURCES = iuup/iuup_test.c
 iuup_iuup_test_LDADD = $(LDADD) $(top_builddir)/src/gsm/libosmogsm.la
 
+v110_test_frame_SOURCES = v110/test_frame.c
+v110_test_frame_LDADD = $(LDADD) $(top_builddir)/src/isdn/libosmoisdn.la
+
+v110_test_ra1_SOURCES = v110/test_ra1.c
+v110_test_ra1_LDADD = $(LDADD) $(top_builddir)/src/isdn/libosmoisdn.la
+
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
 $(srcdir)/package.m4: $(top_srcdir)/configure.ac
 	:;{ \
@@ -437,6 +445,8 @@ EXTRA_DIST = testsuite.at $(srcdir)/package.m4 $(TESTSUITE)		\
 	     smscb/smscb_test.ok \
 	     smscb/gsm0341_test.ok \
 	     smscb/cbsp_test.ok \
+	     v110/test_frame.ok \
+	     v110/test_ra1.ok \
 	     $(NULL)
 
 if ENABLE_LIBSCTP
@@ -640,6 +650,10 @@ endif
 		>$(srcdir)/time_cc/time_cc_test.ok
 	iuup/iuup_test \
 		>$(srcdir)/iuup/iuup_test.ok
+	v110/test_frame \
+		>$(srcdir)/v110/test_frame.ok
+	v110/test_ra1 \
+		>$(srcdir)/v110/test_ra1.ok
 
 check-local: atconfig $(TESTSUITE)
 	[ -e /proc/cpuinfo ] && cat /proc/cpuinfo
diff --git a/tests/testsuite.at b/tests/testsuite.at
index e447cdc21..39cf54ad6 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -490,3 +490,15 @@ AT_KEYWORDS([iuup])
 cat $abs_srcdir/iuup/iuup_test.ok > expout
 AT_CHECK([$abs_top_builddir/tests/iuup/iuup_test], [0], [expout], [ignore])
 AT_CLEANUP
+
+AT_SETUP([v110_test_frame])
+AT_KEYWORDS([v110_test_frame])
+cat $abs_srcdir/v110/test_frame.ok > expout
+AT_CHECK([$abs_top_builddir/tests/v110/test_frame], [], [expout],[])
+AT_CLEANUP
+
+AT_SETUP([v110_test_ra1])
+AT_KEYWORDS([v110_test_ra1])
+cat $abs_srcdir/v110/test_ra1.ok > expout
+AT_CHECK([$abs_top_builddir/tests/v110/test_ra1], [], [expout],[])
+AT_CLEANUP
diff --git a/tests/v110/test_frame.c b/tests/v110/test_frame.c
new file mode 100644
index 000000000..ebc617c0e
--- /dev/null
+++ b/tests/v110/test_frame.c
@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/isdn/v110.h>
+
+
+static void test_frame_enc(void)
+{
+	struct osmo_v110_decoded_frame fr;
+	ubit_t bits[80];
+	unsigned int i;
+
+	memset(&fr, 0, sizeof(fr));
+
+	/* we abuse the fact that ubit_t is 8bit so we can actually
+	 * store integer values to clearly identify which bit ends up where */
+
+	/* D1..D48: 101..148 */
+	for (i = 0; i < ARRAY_SIZE(fr.d_bits); i++)
+		fr.d_bits[i] = 101 + i;
+	/* E1..E7: 201..207 */
+	for (i = 0; i < ARRAY_SIZE(fr.e_bits); i++)
+		fr.e_bits[i] = 201 + i;
+	/* S1..S9: 211..219 */
+	for (i = 0; i < ARRAY_SIZE(fr.s_bits); i++)
+		fr.s_bits[i] = 211 + i;
+	/* X1..X2: 221..222 */
+	for (i = 0; i < ARRAY_SIZE(fr.x_bits); i++)
+		fr.x_bits[i] = 221 + i;
+
+	/* run encoder and dump to stdout */
+	memset(bits, 0xff, sizeof(bits));
+	osmo_v110_encode_frame(bits, sizeof(bits), &fr);
+	osmo_v110_ubit_dump(stdout, bits, sizeof(bits));
+
+	/* run decoder on what we just encoded */
+	memset(&fr, 0, sizeof(fr));
+	osmo_v110_decode_frame(&fr, bits, sizeof(bits));
+
+	/* re-encode and dump again 'expout' will match it. */
+	memset(bits, 0xff, sizeof(bits));
+	osmo_v110_encode_frame(bits, sizeof(bits), &fr);
+	osmo_v110_ubit_dump(stdout, bits, sizeof(bits));
+}
+
+
+int main(int argc, char **argv)
+{
+	test_frame_enc();
+}
+
diff --git a/tests/v110/test_frame.ok b/tests/v110/test_frame.ok
new file mode 100644
index 000000000..ecefaa87d
--- /dev/null
+++ b/tests/v110/test_frame.ok
@@ -0,0 +1,20 @@
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	211
+1	107	108	109	110	111	112	221
+1	113	114	115	116	117	118	213
+1	119	120	121	122	123	124	214
+1	201	202	203	204	205	206	207
+1	125	126	127	128	129	130	216
+1	131	132	133	134	135	136	222
+1	137	138	139	140	141	142	218
+1	143	144	145	146	147	148	219
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	211
+1	107	108	109	110	111	112	221
+1	113	114	115	116	117	118	213
+1	119	120	121	122	123	124	214
+1	201	202	203	204	205	206	207
+1	125	126	127	128	129	130	216
+1	131	132	133	134	135	136	222
+1	137	138	139	140	141	142	218
+1	143	144	145	146	147	148	219
diff --git a/tests/v110/test_ra1.c b/tests/v110/test_ra1.c
new file mode 100644
index 000000000..775ec4b76
--- /dev/null
+++ b/tests/v110/test_ra1.c
@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/isdn/v110.h>
+
+
+static void test_ra1(enum osmo_v100_sync_ra1_rate rate)
+{
+	int user_rate = osmo_v110_sync_ra1_get_user_data_rate(rate);
+	int user_data_chunk_bits = osmo_v110_sync_ra1_get_user_data_chunk_bitlen(rate);
+	struct osmo_v110_decoded_frame fr;
+	ubit_t user_bits[48];
+	ubit_t bits[80];
+	unsigned int i;
+	int rc;
+
+	printf("\n======= User data rate %u\n", user_rate);
+
+	/* we abuse the fact that ubit_t is 8bit so we can actually
+	 * store integer values to clearly identify which bit ends up where */
+	memset(user_bits, 0xFE, sizeof(user_bits));
+	for (i = 0; i < user_data_chunk_bits; i++)
+		user_bits[i] = 101 + i;
+
+	printf("user_bits: ");
+	for (i = 0; i < user_data_chunk_bits; i++)
+		printf("%03d ", user_bits[i]);
+	printf("\n");
+
+	/* generate the decoded v.110 frame */
+	memset(&fr, 0, sizeof(fr));
+	rc = osmo_v110_sync_ra1_user_to_ir(rate, &fr, user_bits, user_data_chunk_bits);
+	OSMO_ASSERT(rc == 0);
+
+	/* run encoder and dump to stdout */
+	memset(bits, 0xff, sizeof(bits));
+	osmo_v110_encode_frame(bits, sizeof(bits), &fr);
+	printf("dumping %u encoded bits in V.110 frame:\n", user_data_chunk_bits);
+	osmo_v110_ubit_dump(stdout, bits, sizeof(bits));
+
+	/* run decoder on what we just encoded */
+	memset(&fr, 0, sizeof(fr));
+	osmo_v110_decode_frame(&fr, bits, sizeof(bits));
+	printf("dumping re-decoded V.110 frame:\n");
+	printf("E-bits: %s\n", osmo_hexdump(fr.e_bits, sizeof(fr.e_bits)));
+	printf("S-bits: %s\n", osmo_hexdump(fr.s_bits, sizeof(fr.s_bits)));
+
+	/* re-encode and dump again 'expout' will match it. */
+	memset(user_bits, 0xff, sizeof(user_bits));
+	rc = osmo_v110_sync_ra1_ir_to_user(rate, user_bits, sizeof(user_bits), &fr);
+	if (rc != user_data_chunk_bits) {
+		fprintf(stderr, "ERROR: adapt_ir_to_user() returned %d, expected %u\n", rc,
+			user_data_chunk_bits);
+		exit(23);
+	}
+	fprintf(stdout, "re-decoded user bits: ");
+	for (i = 0; i < user_data_chunk_bits; i++)
+		printf("%03d ", user_bits[i]);
+	printf("\n");
+}
+
+
+int main(int argc, char **argv)
+{
+	for (int i = 0; i < _NUM_OSMO_V110_SYNC_RA1; i++)
+		test_ra1(i);
+}
+
diff --git a/tests/v110/test_ra1.ok b/tests/v110/test_ra1.ok
new file mode 100644
index 000000000..8a61fc3fb
--- /dev/null
+++ b/tests/v110/test_ra1.ok
@@ -0,0 +1,216 @@
+
+======= User data rate 600
+user_bits: 101 102 103 104 105 106 
+dumping 6 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	101	101	101	101	101	0
+1	101	101	102	102	102	102	0
+1	102	102	102	102	103	103	0
+1	103	103	103	103	103	103	0
+1	1	0	0	0	0	0	0
+1	104	104	104	104	104	104	0
+1	104	104	105	105	105	105	0
+1	105	105	105	105	106	106	0
+1	106	106	106	106	106	106	0
+dumping re-decoded V.110 frame:
+E-bits: 01 00 00 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 
+
+======= User data rate 1200
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 
+dumping 12 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	101	101	101	102	102	0
+1	102	102	103	103	103	103	0
+1	104	104	104	104	105	105	0
+1	105	105	106	106	106	106	0
+1	0	1	0	0	0	0	0
+1	107	107	107	107	108	108	0
+1	108	108	109	109	109	109	0
+1	110	110	110	110	111	111	0
+1	111	111	112	112	112	112	0
+dumping re-decoded V.110 frame:
+E-bits: 00 01 00 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 
+
+======= User data rate 2400
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 
+dumping 24 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	101	102	102	103	103	0
+1	104	104	105	105	106	106	0
+1	107	107	108	108	109	109	0
+1	110	110	111	111	112	112	0
+1	1	1	0	0	0	0	0
+1	113	113	114	114	115	115	0
+1	116	116	117	117	118	118	0
+1	119	119	120	120	121	121	0
+1	122	122	123	123	124	124	0
+dumping re-decoded V.110 frame:
+E-bits: 01 01 00 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 
+
+======= User data rate 4800
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+dumping 48 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	111	112	0
+1	113	114	115	116	117	118	0
+1	119	120	121	122	123	124	0
+1	0	1	1	0	0	0	0
+1	125	126	127	128	129	130	0
+1	131	132	133	134	135	136	0
+1	137	138	139	140	141	142	0
+1	143	144	145	146	147	148	0
+dumping re-decoded V.110 frame:
+E-bits: 00 01 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+
+======= User data rate 7200
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 
+dumping 36 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	1	1	0
+1	111	112	1	1	113	114	0
+1	1	1	115	116	117	118	0
+1	1	0	1	0	0	0	0
+1	119	120	121	122	123	124	0
+1	125	126	127	128	1	1	0
+1	129	130	1	1	131	132	0
+1	1	1	133	134	135	136	0
+dumping re-decoded V.110 frame:
+E-bits: 01 00 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 
+
+======= User data rate 9600
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+dumping 48 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	111	112	0
+1	113	114	115	116	117	118	0
+1	119	120	121	122	123	124	0
+1	0	1	1	0	0	0	0
+1	125	126	127	128	129	130	0
+1	131	132	133	134	135	136	0
+1	137	138	139	140	141	142	0
+1	143	144	145	146	147	148	0
+dumping re-decoded V.110 frame:
+E-bits: 00 01 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+
+======= User data rate 12000
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 
+dumping 30 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	1	1	0
+1	111	112	1	1	113	114	0
+1	1	1	115	1	1	1	0
+1	0	0	1	0	0	0	0
+1	116	117	118	119	120	121	0
+1	122	123	124	125	1	1	0
+1	126	127	1	1	128	129	0
+1	1	1	130	1	1	1	0
+dumping re-decoded V.110 frame:
+E-bits: 00 00 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 
+
+======= User data rate 14400
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 
+dumping 36 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	1	1	0
+1	111	112	1	1	113	114	0
+1	1	1	115	116	117	118	0
+1	1	0	1	0	0	0	0
+1	119	120	121	122	123	124	0
+1	125	126	127	128	1	1	0
+1	129	130	1	1	131	132	0
+1	1	1	133	134	135	136	0
+dumping re-decoded V.110 frame:
+E-bits: 01 00 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 
+
+======= User data rate 19200
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+dumping 48 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	111	112	0
+1	113	114	115	116	117	118	0
+1	119	120	121	122	123	124	0
+1	0	1	1	0	0	0	0
+1	125	126	127	128	129	130	0
+1	131	132	133	134	135	136	0
+1	137	138	139	140	141	142	0
+1	143	144	145	146	147	148	0
+dumping re-decoded V.110 frame:
+E-bits: 00 01 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+
+======= User data rate 24000
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 
+dumping 30 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	1	1	0
+1	111	112	1	1	113	114	0
+1	1	1	115	1	1	1	0
+1	0	0	1	0	0	0	0
+1	116	117	118	119	120	121	0
+1	122	123	124	125	1	1	0
+1	126	127	1	1	128	129	0
+1	1	1	130	1	1	1	0
+dumping re-decoded V.110 frame:
+E-bits: 00 00 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 
+
+======= User data rate 28800
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 
+dumping 36 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	1	1	0
+1	111	112	1	1	113	114	0
+1	1	1	115	116	117	118	0
+1	1	0	1	0	0	0	0
+1	119	120	121	122	123	124	0
+1	125	126	127	128	1	1	0
+1	129	130	1	1	131	132	0
+1	1	1	133	134	135	136	0
+dumping re-decoded V.110 frame:
+E-bits: 01 00 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 
+
+======= User data rate 38400
+user_bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 
+dumping 48 encoded bits in V.110 frame:
+0	0	0	0	0	0	0	0
+1	101	102	103	104	105	106	0
+1	107	108	109	110	111	112	0
+1	113	114	115	116	117	118	0
+1	119	120	121	122	123	124	0
+1	0	1	1	0	0	0	0
+1	125	126	127	128	129	130	0
+1	131	132	133	134	135	136	0
+1	137	138	139	140	141	142	0
+1	143	144	145	146	147	148	0
+dumping re-decoded V.110 frame:
+E-bits: 00 01 01 00 00 00 00 
+S-bits: 00 00 00 00 00 00 00 00 00 
+re-decoded user bits: 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148