diff --git a/include/osmocom/msc/rtp_stream.h b/include/osmocom/msc/rtp_stream.h
new file mode 100644
index 0000000..794e806
--- /dev/null
+++ b/include/osmocom/msc/rtp_stream.h
@@ -0,0 +1,64 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <osmocom/core/sockaddr_str.h>
+#include <osmocom/mgcp_client/mgcp_client.h>
+
+struct gsm_trans;
+
+struct osmo_fsm_inst;
+struct call_leg;
+struct osmo_mgcpc_ep;
+struct osmo_mgcpc_ep_ci;
+
+enum rtp_direction {
+	RTP_TO_RAN,
+	RTP_TO_CN,
+};
+
+extern const struct value_string rtp_direction_names[];
+static inline const char *rtp_direction_name(enum rtp_direction val)
+{ return get_value_string(rtp_direction_names, val); }
+
+/* A single bidirectional RTP hop between remote and MGW's local RTP port. */
+struct rtp_stream {
+	struct osmo_fsm_inst *fi;
+	struct call_leg *parent_call_leg;
+	enum rtp_direction dir;
+
+	uint32_t call_id;
+
+	/* Backpointer for callers (optional) */
+	struct gsm_trans *for_trans;
+
+	struct osmo_sockaddr_str local;
+	struct osmo_sockaddr_str remote;
+	bool remote_sent_to_mgw;
+
+	bool codec_known;
+	enum mgcp_codecs codec;
+	bool codec_sent_to_mgw;
+
+	struct osmo_mgcpc_ep_ci *ci;
+
+	enum mgcp_connection_mode crcx_conn_mode;
+};
+
+#define RTP_STREAM_FMT "local=" RTP_IP_PORT_FMT ",remote=" RTP_IP_PORT_FMT
+#define RTP_STREAM_ARGS(RS) RTP_IP_PORT_ARGS(&(RS)->local), RTP_IP_PORT_ARGS(&(RS)->remote),
+
+struct rtp_stream *rtp_stream_alloc(struct call_leg *parent_call_leg, enum rtp_direction dir,
+				    uint32_t call_id, struct gsm_trans *for_trans);
+
+int rtp_stream_ensure_ci(struct rtp_stream *rtps, struct osmo_mgcpc_ep *at_endpoint);
+int rtp_stream_do_mdcx(struct rtp_stream *rtps);
+
+void rtp_stream_set_codec(struct rtp_stream *rtps, enum mgcp_codecs codec);
+void rtp_stream_set_remote_addr(struct rtp_stream *rtps, const struct osmo_sockaddr_str *r);
+int rtp_stream_commit(struct rtp_stream *rtps);
+
+void rtp_stream_release(struct rtp_stream *rtps);
+
+bool rtp_stream_is_established(struct rtp_stream *rtps);