diff --git a/include/osmocom/mgcp/mgcp_internal.h b/include/osmocom/mgcp/mgcp_internal.h
new file mode 100644
index 0000000..dcc75f1
--- /dev/null
+++ b/include/osmocom/mgcp/mgcp_internal.h
@@ -0,0 +1,337 @@
+/* MGCP Private Data */
+
+/*
+ * (C) 2009-2012 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2009-2012 by On-Waves
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <string.h>
+
+#include <osmocom/core/select.h>
+
+#define CI_UNUSED 0
+
+enum mgcp_trunk_type {
+	MGCP_TRUNK_VIRTUAL,
+	MGCP_TRUNK_E1,
+};
+
+struct mgcp_rtp_stream_state {
+	uint32_t ssrc;
+	uint16_t last_seq;
+	uint32_t last_timestamp;
+	uint32_t err_ts_counter;
+	int32_t last_tsdelta;
+	uint32_t last_arrival_time;
+};
+
+struct mgcp_rtp_state {
+	int initialized;
+	int patch_ssrc;
+
+	uint32_t orig_ssrc;
+
+	int seq_offset;
+
+	int32_t  timestamp_offset;
+	uint32_t packet_duration;
+
+	struct mgcp_rtp_stream_state in_stream;
+	struct mgcp_rtp_stream_state out_stream;
+
+	/* jitter and packet loss calculation */
+	int stats_initialized;
+	uint16_t stats_base_seq;
+	uint16_t stats_max_seq;
+	uint32_t stats_ssrc;
+	uint32_t stats_jitter;
+	int32_t stats_transit;
+	int stats_cycles;
+	bool patched_first_rtp_payload; /* FIXME: drop this, see OS#2459 */
+};
+
+struct mgcp_rtp_codec {
+	uint32_t rate;
+	int channels;
+	uint32_t frame_duration_num;
+	uint32_t frame_duration_den;
+
+	int payload_type;
+	char *audio_name;
+	char *subtype_name;
+};
+
+struct mgcp_rtp_end {
+	/* statistics */
+	unsigned int packets;
+	unsigned int octets;
+	unsigned int dropped_packets;
+	struct in_addr addr;
+
+	/* in network byte order */
+	int rtp_port, rtcp_port;
+
+	/* audio codec information */
+	struct mgcp_rtp_codec codec;
+	struct mgcp_rtp_codec alt_codec; /* TODO/XXX: make it generic */
+
+	/* per endpoint data */
+	int  frames_per_packet;
+	uint32_t packet_duration_ms;
+	char *fmtp_extra;
+	int output_enabled;
+	int force_output_ptime;
+
+	/* RTP patching */
+	int force_constant_ssrc; /* -1: always, 0: don't, 1: once */
+	int force_aligned_timing;
+	void *rtp_process_data;
+
+	/*
+	 * Each end has a socket...
+	 */
+	struct osmo_fd rtp;
+	struct osmo_fd rtcp;
+
+	int local_port;
+	int local_alloc;
+};
+
+enum {
+	MGCP_TAP_BTS_IN,
+	MGCP_TAP_BTS_OUT,
+	MGCP_TAP_NET_IN,
+	MGCP_TAP_NET_OUT,
+
+	/* last element */
+	MGCP_TAP_COUNT
+};
+
+struct mgcp_rtp_tap {
+	int enabled;
+	struct sockaddr_in forward;
+};
+
+struct mgcp_lco {
+	char *string;
+	char *codec;
+	int pkt_period_min; /* time in ms */
+	int pkt_period_max; /* time in ms */
+};
+
+enum mgcp_type {
+	MGCP_RTP_DEFAULT	= 0,
+	MGCP_RTP_TRANSCODED,
+	MGCP_OSMUX_BSC,
+	MGCP_OSMUX_BSC_NAT,
+};
+
+#include <osmocom/legacy_mgcp/osmux.h>
+
+struct mgcp_endpoint {
+	int allocated;
+	uint32_t ci;
+	char *callid;
+	struct mgcp_lco local_options;
+	int conn_mode;
+	int orig_mode;
+
+	/* backpointer */
+	struct mgcp_config *cfg;
+	struct mgcp_trunk_config *tcfg;
+
+	/* port status for bts/net */
+	struct mgcp_rtp_end bts_end;
+	struct mgcp_rtp_end net_end;
+
+	/*
+	 * For transcoding we will send from the local_port
+	 * of trans_bts and it will arrive at trans_net from
+	 * where we will forward it to the network.
+	 */
+	struct mgcp_rtp_end trans_bts;
+	struct mgcp_rtp_end trans_net;
+	enum mgcp_type type;
+
+	/* sequence bits */
+	struct mgcp_rtp_state net_state;
+	struct mgcp_rtp_state bts_state;
+
+	/* fields for re-transmission */
+	char *last_trans;
+	char *last_response;
+
+	/* tap for the endpoint */
+	struct mgcp_rtp_tap taps[MGCP_TAP_COUNT];
+
+	struct {
+		/* Osmux state: disabled, activating, active */
+		enum osmux_state state;
+		/* Allocated Osmux circuit ID for this endpoint */
+		int allocated_cid;
+		/* Used Osmux circuit ID for this endpoint */
+		uint8_t cid;
+		/* handle to batch messages */
+		struct osmux_in_handle *in;
+		/* handle to unbatch messages */
+		struct osmux_out_handle out;
+		/* statistics */
+		struct {
+			uint32_t chunks;
+			uint32_t octets;
+		} stats;
+	} osmux;
+};
+
+#define for_each_line(line, save)			\
+	for (line = strline_r(NULL, &save); line;\
+	     line = strline_r(NULL, &save))
+
+static inline char *strline_r(char *str, char **saveptr)
+{
+	char *result;
+
+	if (str)
+		*saveptr = str;
+
+	result = *saveptr;
+
+	if (*saveptr != NULL) {
+		*saveptr = strpbrk(*saveptr, "\r\n");
+
+		if (*saveptr != NULL) {
+			char *eos = *saveptr;
+
+			if ((*saveptr)[0] == '\r' && (*saveptr)[1] == '\n')
+				(*saveptr)++;
+			(*saveptr)++;
+			if ((*saveptr)[0] == '\0')
+				*saveptr = NULL;
+
+			*eos = '\0';
+		}
+	}
+
+	return result;
+}
+
+
+
+#define ENDPOINT_NUMBER(endp) abs((int)(endp - endp->tcfg->endpoints))
+
+/**
+ * Internal structure while parsing a request
+ */
+struct mgcp_parse_data {
+	struct mgcp_config *cfg;
+	struct mgcp_endpoint *endp;
+	char *trans;
+	char *save;
+	int found;
+};
+
+int mgcp_send_dummy(struct mgcp_endpoint *endp);
+int mgcp_bind_bts_rtp_port(struct mgcp_endpoint *endp, int rtp_port);
+int mgcp_bind_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port);
+int mgcp_bind_trans_bts_rtp_port(struct mgcp_endpoint *enp, int rtp_port);
+int mgcp_bind_trans_net_rtp_port(struct mgcp_endpoint *enp, int rtp_port);
+int mgcp_free_rtp_port(struct mgcp_rtp_end *end);
+
+/* For transcoding we need to manage an in and an output that are connected */
+static inline int endp_back_channel(int endpoint)
+{
+	return endpoint + 60;
+}
+
+struct mgcp_trunk_config *mgcp_trunk_alloc(struct mgcp_config *cfg, int index);
+struct mgcp_trunk_config *mgcp_trunk_num(struct mgcp_config *cfg, int index);
+
+void mgcp_rtp_end_config(struct mgcp_endpoint *endp, int expect_ssrc_change,
+			 struct mgcp_rtp_end *rtp);
+uint32_t mgcp_rtp_packet_duration(struct mgcp_endpoint *endp,
+				  struct mgcp_rtp_end *rtp);
+
+void mgcp_state_calc_loss(struct mgcp_rtp_state *s, struct mgcp_rtp_end *,
+			uint32_t *expected, int *loss);
+uint32_t mgcp_state_calc_jitter(struct mgcp_rtp_state *);
+
+/* payload processing default functions */
+int mgcp_rtp_processing_default(struct mgcp_endpoint *endp, struct mgcp_rtp_end *dst_end,
+				char *data, int *len, int buf_size);
+
+int mgcp_setup_rtp_processing_default(struct mgcp_endpoint *endp,
+				      struct mgcp_rtp_end *dst_end,
+				      struct mgcp_rtp_end *src_end);
+
+void mgcp_get_net_downlink_format_default(struct mgcp_endpoint *endp,
+					  int *payload_type,
+					  const char**subtype_name,
+					  const char**fmtp_extra);
+
+/* internal RTP Annex A counting */
+void mgcp_rtp_annex_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *state,
+			const uint16_t seq, const int32_t transit,
+			const uint32_t ssrc);
+
+int mgcp_set_ip_tos(int fd, int tos);
+
+enum {
+	MGCP_DEST_NET = 0,
+	MGCP_DEST_BTS,
+};
+
+
+#define MGCP_DUMMY_LOAD 0x23
+
+
+/**
+ * SDP related information
+ */
+/* Assume audio frame length of 20ms */
+#define DEFAULT_RTP_AUDIO_FRAME_DUR_NUM 20
+#define DEFAULT_RTP_AUDIO_FRAME_DUR_DEN 1000
+#define DEFAULT_RTP_AUDIO_PACKET_DURATION_MS 20
+#define DEFAULT_RTP_AUDIO_DEFAULT_RATE  8000
+#define DEFAULT_RTP_AUDIO_DEFAULT_CHANNELS 1
+
+#define PTYPE_UNDEFINED (-1)
+int mgcp_parse_sdp_data(struct mgcp_endpoint *endp, struct mgcp_rtp_end *rtp, struct mgcp_parse_data *p);
+int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec,
+			int payload_type, const char *audio_name);
+
+
+/**
+ * Internal network related
+ */
+static inline const char *mgcp_net_src_addr(struct mgcp_endpoint *endp)
+{
+	if (endp->cfg->net_ports.bind_addr)
+		return endp->cfg->net_ports.bind_addr;
+	return endp->cfg->source_addr;
+}
+
+static inline const char *mgcp_bts_src_addr(struct mgcp_endpoint *endp)
+{
+	if (endp->cfg->bts_ports.bind_addr)
+		return endp->cfg->bts_ports.bind_addr;
+	return endp->cfg->source_addr;
+}
+
+int mgcp_msg_terminate_nul(struct msgb *msg);