diff --git a/src/Makefile.am b/src/Makefile.am
index de924a6..f85a456 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -43,6 +43,7 @@
 	csn1.c \
 	gsm_rlcmac.c \
 	gprs_bssgp_pcu.c \
+	gprs_bssgp_rim.c \
 	gprs_rlcmac.cpp \
 	gprs_rlcmac_sched.cpp \
 	gprs_rlcmac_meas.cpp \
@@ -81,6 +82,7 @@
 	csn1.h \
 	gsm_rlcmac.h \
 	gprs_bssgp_pcu.h \
+	gprs_bssgp_rim.h \
 	gprs_rlcmac.h \
 	gprs_ms.h \
 	gprs_ms_storage.h \
diff --git a/src/gprs_bssgp_pcu.c b/src/gprs_bssgp_pcu.c
index c5cc39d..81a6518 100644
--- a/src/gprs_bssgp_pcu.c
+++ b/src/gprs_bssgp_pcu.c
@@ -20,6 +20,7 @@
 
 #include <gprs_rlcmac.h>
 #include <gprs_bssgp_pcu.h>
+#include <gprs_bssgp_rim.h>
 #include <pcu_l1_if.h>
 #include <gprs_debug.h>
 #include <bts.h>
@@ -419,10 +420,22 @@
 	int rc = 0;
 	struct bssgp_bvc_ctx *bctx;
 
-	if (pdu_type == BSSGP_PDUT_STATUS)
+	switch (pdu_type) {
+	case BSSGP_PDUT_STATUS:
 		/* Pass the message to the generic BSSGP parser, which handles
 		 * STATUS and RESET messages in either direction. */
+	case BSSGP_PDUT_RAN_INFO:
+	case BSSGP_PDUT_RAN_INFO_REQ:
+	case BSSGP_PDUT_RAN_INFO_ACK:
+	case BSSGP_PDUT_RAN_INFO_ERROR:
+	case BSSGP_PDUT_RAN_INFO_APP_ERROR:
+		/* Also pass all RIM related messages to the generic BSSGP
+		 * parser so that it can deliver primitive to the RIM SAP
+		 * (SAP_BSSGP_RIM) */
 		return bssgp_rcvmsg(msg);
+	default:
+		break;
+	}
 
 	/* Identifiers from DOWN: NSEI, BVCI (both in msg->cb) */
 
@@ -552,6 +565,8 @@
 		if (oph->primitive == PRIM_NM_STATUS)
 			handle_nm_status(bp);
 		break;
+	case SAP_BSSGP_RIM:
+		return handle_rim(bp);
 	default:
 		break;
 	}
diff --git a/src/gprs_bssgp_rim.c b/src/gprs_bssgp_rim.c
new file mode 100644
index 0000000..cf43a8f
--- /dev/null
+++ b/src/gprs_bssgp_rim.c
@@ -0,0 +1,169 @@
+/* gprs_bssgp_pcu.cpp
+ *
+ * Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <osmocom/gprs/gprs_bssgp.h>
+#include <osmocom/gprs/gprs_bssgp_rim.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/gsm/tlv.h>
+#include <osmocom/gprs/gprs_ns.h>
+#include <osmocom/core/prim.h>
+
+#include "gprs_debug.h"
+#include "gprs_pcu.h"
+
+#define LOGPRIM(nsei, level, fmt, args...) \
+	LOGP(DRIM, level, "(NSEI=%u) " fmt, nsei, ## args)
+
+static inline void gprs_ra_id_ci_to_cgi_ps(struct osmo_cell_global_id_ps *cgi_ps,
+					   const struct gprs_ra_id *raid, uint16_t cid)
+{
+	*cgi_ps = (struct osmo_cell_global_id_ps) {
+		.rai.lac.plmn.mcc = raid->mcc,
+		.rai.lac.plmn.mnc = raid->mnc,
+		.rai.lac.plmn.mnc_3_digits = raid->mnc_3_digits,
+		.rai.lac.lac = raid->lac,
+		.rai.rac = raid->rac,
+		.cell_identity = cid,
+	};
+}
+
+/* Mirror RIM routing information of a given PDU, see also 3GPP TS 48.018, section 8c.1.4.3 */
+static void mirror_rim_routing_info(struct bssgp_ran_information_pdu *to_pdu,
+				    const struct bssgp_ran_information_pdu *from_pdu)
+{
+	memcpy(&to_pdu->routing_info_dest, &from_pdu->routing_info_src, sizeof(to_pdu->routing_info_dest));
+	memcpy(&to_pdu->routing_info_src, &from_pdu->routing_info_dest, sizeof(to_pdu->routing_info_src));
+}
+
+/* Format a RAN INFORMATION ERROR PDU */
+static void format_response_pdu_err(struct bssgp_ran_information_pdu *resp_pdu,
+				    const struct bssgp_ran_information_pdu *req_pdu)
+{
+	memset(resp_pdu, 0, sizeof(*resp_pdu));
+	mirror_rim_routing_info(resp_pdu, req_pdu);
+
+	resp_pdu->decoded.err_rim_cont = (struct bssgp_ran_inf_err_rim_cont) {
+		.app_id = BSSGP_RAN_INF_APP_ID_NACC,
+		.prot_ver = 1,
+		.err_pdu = req_pdu->rim_cont,
+		.err_pdu_len = req_pdu->rim_cont_len,
+	};
+
+	resp_pdu->decoded_present = true;
+	resp_pdu->rim_cont_iei = BSSGP_IE_RI_ERROR_RIM_COINTAINER;
+}
+
+/* Check if the application ID in the request PDU is actually BSSGP_RAN_INF_APP_ID_NACC */
+static const enum bssgp_ran_inf_app_id *get_app_id(const struct bssgp_ran_information_pdu *pdu)
+{
+	switch (pdu->rim_cont_iei) {
+	case BSSGP_IE_RI_REQ_RIM_CONTAINER:
+		return &pdu->decoded.req_rim_cont.app_id;
+	case BSSGP_IE_RI_RIM_CONTAINER:
+		return &pdu->decoded.rim_cont.app_id;
+	case BSSGP_IE_RI_APP_ERROR_RIM_CONT:
+		return &pdu->decoded.app_err_rim_cont.app_id;
+	case BSSGP_IE_RI_ACK_RIM_CONTAINER:
+		return &pdu->decoded.ack_rim_cont.app_id;
+	case BSSGP_IE_RI_ERROR_RIM_COINTAINER:
+		return &pdu->decoded.err_rim_cont.app_id;
+	default:
+		return NULL;
+	}
+}
+
+/* Check if the application ID in the request PDU is of a certain type */
+static bool match_app_id(const struct bssgp_ran_information_pdu *pdu, enum bssgp_ran_inf_app_id exp_app_id)
+{
+	const enum bssgp_ran_inf_app_id *app_id = get_app_id(pdu);
+	if (app_id && *app_id == exp_app_id)
+		return true;
+	return false;
+}
+
+int handle_rim(struct osmo_bssgp_prim *bp)
+{
+	struct msgb *msg = bp->oph.msg;
+	uint16_t nsei = msgb_nsei(msg);
+	struct bssgp_ran_information_pdu *pdu = &bp->u.rim_pdu;
+	struct bssgp_ran_information_pdu resp_pdu;
+	struct osmo_cell_global_id_ps dst_addr;
+	struct gprs_rlcmac_bts *bts;
+
+	OSMO_ASSERT (bp->oph.sap == SAP_BSSGP_RIM);
+
+	/* At the moment we only support GERAN, so we block all other network
+	 * types here. */
+	if (pdu->routing_info_dest.discr != BSSGP_RIM_ROUTING_INFO_GERAN) {
+		LOGPRIM(nsei, LOGL_ERROR,
+			"Only GERAN supported, destination cell is not a GERAN cell -- rejected.\n");
+		return bssgp_tx_status(BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
+	}
+
+	/* Check if the RIM pdu is really addressed to this PCU. In case we
+	 * receive a RIM PDU for a cell that is not parented by this PCU we
+	 * are supposed to reject it with a BSSGP STATUS.
+	 * see also: 3GPP TS 48.018, section 8c.3.1.2 */
+	gprs_ra_id_ci_to_cgi_ps(&dst_addr, &pdu->routing_info_dest.geran.raid,
+				pdu->routing_info_dest.geran.cid);
+	bts = gprs_pcu_get_bts_by_cgi_ps(the_pcu, &dst_addr);
+	if (!bts) {
+		LOGPRIM(nsei, LOGL_ERROR, "Cell %s unknown to this pcu\n",
+			osmo_cgi_ps_name(&dst_addr));
+		return bssgp_tx_status(BSSGP_CAUSE_UNKN_DST, NULL, msg);
+	}
+
+	/* Check if the incoming RIM PDU is parseable, if not we must report
+	 * an error to the controlling BSS 3GPP TS 48.018, 8c.3.4 and 8c.3.4.2 */
+	if (!pdu->decoded_present) {
+		LOGPRIM(nsei, LOGL_ERROR, "Errornous RIM PDU received -- rejected.\n");
+		format_response_pdu_err(&resp_pdu, pdu);
+		return 0;
+	}
+
+	/* Check if the RIM container inside the incoming RIM PDU has the correct
+	 * application ID */
+	if (!match_app_id(pdu, BSSGP_RAN_INF_APP_ID_NACC)) {
+		LOGPRIM(nsei, LOGL_ERROR, "RIM PDU with unknown/wrong application ID received -- rejected.\n");
+		format_response_pdu_err(&resp_pdu, pdu);
+		return 0;
+	}
+
+	/* Handle incoming RIM container */
+	switch (pdu->rim_cont_iei) {
+	case BSSGP_IE_RI_REQ_RIM_CONTAINER:
+		LOGPRIM(nsei, LOGL_NOTICE, "Responding to RAN INFORMATION REQUEST not yet implemented!\n");
+		break;
+	case BSSGP_IE_RI_RIM_CONTAINER:
+		LOGPRIM(nsei, LOGL_NOTICE, "Responding to RAN INFORMATION not yet implemented!\n");
+		break;
+	case BSSGP_IE_RI_APP_ERROR_RIM_CONT:
+	case BSSGP_IE_RI_ACK_RIM_CONTAINER:
+	case BSSGP_IE_RI_ERROR_RIM_COINTAINER:
+		LOGPRIM(nsei, LOGL_ERROR, "RIM PDU not handled by this application\n");
+		return -EINVAL;
+	default:
+		/* This should never happen. If the RIM PDU is parsed correctly, then the rim_cont_iei will
+		 * be set to one of the cases above and if parsing fails this switch statement is guarded
+		 * by the check on decoded_present above */
+		OSMO_ASSERT(false);
+	}
+
+	return 0;
+}
diff --git a/src/gprs_bssgp_rim.h b/src/gprs_bssgp_rim.h
new file mode 100644
index 0000000..5fac56f
--- /dev/null
+++ b/src/gprs_bssgp_rim.h
@@ -0,0 +1,24 @@
+/* gprs_bssgp_rim.h
+ *
+ * Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#pragma once
+
+struct osmo_bssgp_prim;
+
+int handle_rim(struct osmo_bssgp_prim *bp);
diff --git a/src/gprs_debug.cpp b/src/gprs_debug.cpp
index a790e3f..669ea27 100644
--- a/src/gprs_debug.cpp
+++ b/src/gprs_debug.cpp
@@ -119,6 +119,13 @@
 		.loglevel = LOGL_NOTICE,
 		.enabled = 1,
 	},
+	[DRIM] = {
+		.name = "DRIM",
+		.color = "\033[1;38m",
+		.description = "RAN Information Management (RIM)",
+		.loglevel = LOGL_NOTICE,
+		.enabled = 1,
+	},
 };
 
 static int filter_fn(const struct log_context *ctx,
diff --git a/src/gprs_debug.h b/src/gprs_debug.h
index 84a0a07..8df405a 100644
--- a/src/gprs_debug.h
+++ b/src/gprs_debug.h
@@ -46,6 +46,7 @@
 	DTBFUL,
 	DNS,
 	DPCU,
+	DRIM,
 	aDebug_LastEntry
 };
 
diff --git a/src/gprs_pcu.c b/src/gprs_pcu.c
index d291e71..32259b8 100644
--- a/src/gprs_pcu.c
+++ b/src/gprs_pcu.c
@@ -116,6 +116,16 @@
 	return NULL;
 }
 
+struct gprs_rlcmac_bts *gprs_pcu_get_bts_by_cgi_ps(struct gprs_pcu *pcu, struct osmo_cell_global_id_ps *cgi_ps)
+{
+	struct gprs_rlcmac_bts *pos;
+	llist_for_each_entry(pos, &pcu->bts_list, list) {
+		if (memcmp(&pos->cgi_ps, cgi_ps, sizeof(*cgi_ps)) == 0)
+			return pos;
+	}
+	return NULL;
+}
+
 void gprs_pcu_set_initial_cs(struct gprs_pcu *pcu, uint8_t cs_dl, uint8_t cs_ul)
 {
 	struct gprs_rlcmac_bts *bts;
diff --git a/src/gprs_pcu.h b/src/gprs_pcu.h
index 058d102..a1cd1ed 100644
--- a/src/gprs_pcu.h
+++ b/src/gprs_pcu.h
@@ -124,6 +124,7 @@
 struct gprs_pcu *gprs_pcu_alloc(void *ctx);
 
 struct gprs_rlcmac_bts *gprs_pcu_get_bts_by_nr(struct gprs_pcu *pcu, uint8_t bts_nr);
+struct gprs_rlcmac_bts *gprs_pcu_get_bts_by_cgi_ps(struct gprs_pcu *pcu, struct osmo_cell_global_id_ps *cgi_ps);
 
 void gprs_pcu_set_initial_cs(struct gprs_pcu *pcu, uint8_t cs_dl, uint8_t cs_ul);
 void gprs_pcu_set_initial_mcs(struct gprs_pcu *pcu, uint8_t mcs_dl, uint8_t mcs_ul);