diff --git a/TODO-RELEASE b/TODO-RELEASE
index 1c5d61f..44ee421 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -1 +1,3 @@
 #component	what		description / commit summary line
+libosmogb > 1.5.1       bssgp_encode_rim_pdu    symbol was not exported previously
+libgtp > 1.7.1          use gtp_ran_info_relay_req(), gtp_set_cb_ran_info_relay_ind()
diff --git a/doc/manuals/chapters/configuration.adoc b/doc/manuals/chapters/configuration.adoc
index 7d3072e..c31761c 100644
--- a/doc/manuals/chapters/configuration.adoc
+++ b/doc/manuals/chapters/configuration.adoc
@@ -11,7 +11,8 @@
 administrator only has to ensure that the NS and BSSGP layer identities
 (NSEI, NSVCI, BVCI) are unique for each PCU connecting to the SGSN.
 
-=== Configuring the Gp interface
+[[gp-if-ggsn]]
+=== Configuring the Gp interface (towards GGSN)
 
 The Gp interface is the GTP-C and GTP-U based interface between the SGSN
 and the GGSNs.  It is implemented via UDP on well-known source and
@@ -67,6 +68,58 @@
 <2> Enable the dynamic GGSN resolving mode
 <3> Specify the IP address of a DNS server for APN resolution
 
+[[gp-if-mme]]
+=== Configuring the Gp interface (towards MME)
+
+The Gp interface also contains the GTP-C v1 based interface between the SGSN
+and the MMEs. This interface between SGSN and MMEs is used to transfer _RAN
+Information Relay_ GTP-C messages between them, which are used as containers to
+allow PCUs under the SGSN and eNodeBs under MMEs to  exchange cell information
+(RIM).
+
+In the SGSN, this interface re-uses the same socket local configuration as per
+the GGSN connections (see _gtp local-ip_ VTY command in <<gp-if-ggsn>>).
+
+Similarly as with GGSNs, (again see <<gp-if-ggsn>>), selection of destination
+peers for the _RAN Information Relay_ message can be configured statically or
+dynamically over GRX.
+
+
+==== Static MME/TAI configuration
+
+In this mode, there is a static list of MMEs and TAIs configured in
+OsmoSGSN via the VTY / config file. One MME in the list can be configured as the
+_default route_, where all unspecified TAIs are routed too.
+
+This is a non-standard method outside of the 3GPP specifications for the
+SGSN, and is typically only used in private/small GPRS networks without
+any access to a GRX.
+
+.Example: Static MME/TAI configuration (single catch-all GGSN)
+----
+sgsn
+...
+ gtp local-ip 192.168.0.10 <1>
+ mme test-mme0 <2>
+  gtp remote-ip 192.168.0.20 <3>
+  gtp ran-info-relay 262 42 3 <4>
+  gtp ran-info-relay 262 42 4
+ mme test-mme1 <5>
+  gtp remote-ip 192.168.0.30
+  gtp ran-info-relay default  <6>
+----
+<1> Configure the local IP address at the SGSN used for Gp/GTP
+<2> Configure an MME named "test-mme0"
+<3> Specify the remote IP address of the MME (for MME "test-mme0")
+<4> Route specified TAIs towards this MME
+<5> Configure an MME named "test-mme1"
+<6> Route all TAIs with an unspecified MME towards MM "test-mme1"
+
+==== Dynamic MME/TAI configuration
+
+Dynamic MME/TAI peer look up over GRX is not yet supported by OsmoSGSN.
+
+
 [[auth-pol]]
 === Authorization Policy
 
diff --git a/include/osmocom/sgsn/Makefile.am b/include/osmocom/sgsn/Makefile.am
index 51bdee8..289f502 100644
--- a/include/osmocom/sgsn/Makefile.am
+++ b/include/osmocom/sgsn/Makefile.am
@@ -22,6 +22,7 @@
 	gprs_subscriber.h \
 	gprs_utils.h \
 	gtphub.h \
+	gtp_mme.h \
 	sgsn.h \
 	sgsn_rim.h \
 	signal.h \
diff --git a/include/osmocom/sgsn/gtp_mme.h b/include/osmocom/sgsn/gtp_mme.h
new file mode 100644
index 0000000..ceea405
--- /dev/null
+++ b/include/osmocom/sgsn/gtp_mme.h
@@ -0,0 +1,41 @@
+#pragma once
+
+#include <netinet/in.h>
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/gprs/protocol/gsm_24_301.h>
+
+struct gsn_t;
+
+struct mme_rim_route {
+	struct llist_head list; /* item in struct sgsn_mme_ctx */
+	struct osmo_eutran_tai tai;
+};
+
+struct sgsn_mme_ctx {
+	struct llist_head list; /* item in sgsn_mme_ctxts */
+	struct llist_head routes; /* list of struct mme_rim_route */
+	struct sgsn_instance *sgsn; /* backpointer */
+	char *name;
+	struct in_addr remote_addr;
+
+	/* is it the default route for outgoing message? are all incoming messages accepted? */
+	bool default_route;
+};
+struct sgsn_mme_ctx *sgsn_mme_ctx_alloc(struct sgsn_instance *sgsn, const char *name);
+struct sgsn_mme_ctx *sgsn_mme_ctx_find_alloc(struct sgsn_instance *sgsn, const char *name);
+void sgsn_mme_ctx_free(struct sgsn_mme_ctx *mme);
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_name(const struct sgsn_instance *sgsn, const char *name);
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_addr(const struct sgsn_instance *sgsn, const struct in_addr *addr);
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_route(const struct sgsn_instance *sgsn, const struct osmo_eutran_tai *tai);
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_default_route(const struct sgsn_instance *sgsn);
+
+void sgsn_mme_ctx_route_add(struct sgsn_mme_ctx *mme, const struct osmo_eutran_tai *tai);
+void sgsn_mme_ctx_route_del(struct sgsn_mme_ctx *mme, const struct osmo_eutran_tai *tai);
+
+#define LOGMME(mme, cat, level, fmt, args...) { \
+	char _buf[INET_ADDRSTRLEN]; \
+	LOGP(cat, level, "MME(%s:%s): " fmt, (mme)->name, inet_ntop(AF_INET, &(mme)->remote_addr, _buf, sizeof(_buf)), ## args); \
+	} while (0)
diff --git a/include/osmocom/sgsn/sgsn.h b/include/osmocom/sgsn/sgsn.h
index d9ef938..b686c7c 100644
--- a/include/osmocom/sgsn/sgsn.h
+++ b/include/osmocom/sgsn/sgsn.h
@@ -6,7 +6,10 @@
 #include <osmocom/core/select.h>
 #include <osmocom/crypt/gprs_cipher.h>
 #include <osmocom/gprs/gprs_ns2.h>
+#include <osmocom/gprs/gprs_bssgp.h>
+
 #include <osmocom/sgsn/gprs_sgsn.h>
+#include <osmocom/sgsn/gtp_mme.h>
 #include <osmocom/gsm/oap_client.h>
 #include <osmocom/gsupclient/gsup_client.h>
 #include <osmocom/sgsn/common.h>
@@ -145,6 +148,8 @@
 	struct ares_addr_node *ares_servers;
 
 	struct rate_ctr_group *rate_ctrs;
+
+	struct llist_head mme_list; /* list of struct sgsn_mme_ctx */
 };
 
 extern struct sgsn_instance *sgsn;
@@ -169,6 +174,7 @@
 void sgsn_pdp_upd_gtp_u(struct sgsn_pdp_ctx *pdp, void *addr, size_t alen);
 void sgsn_ggsn_echo_req(struct sgsn_ggsn_ctx *ggc);
 int send_act_pdp_cont_acc(struct sgsn_pdp_ctx *pctx);
+int sgsn_mme_ran_info_req(struct sgsn_mme_ctx *mme, const struct bssgp_ran_information_pdu *pdu);
 
 /* gprs_sndcp.c */
 
diff --git a/include/osmocom/sgsn/sgsn_rim.h b/include/osmocom/sgsn/sgsn_rim.h
index ca3660b..aa5a726 100644
--- a/include/osmocom/sgsn/sgsn_rim.h
+++ b/include/osmocom/sgsn/sgsn_rim.h
@@ -1,3 +1,6 @@
 #pragma once
 
-int sgsn_rim_rx(struct osmo_bssgp_prim *bp, struct msgb *msg);
+struct sgsn_mme_ctx;
+
+int sgsn_rim_rx_from_gb(struct osmo_bssgp_prim *bp, struct msgb *msg);
+int sgsn_rim_rx_from_gtp(struct bssgp_ran_information_pdu *pdu, struct sgsn_mme_ctx *mme);
diff --git a/include/osmocom/sgsn/vty.h b/include/osmocom/sgsn/vty.h
index bd469ef..a273222 100644
--- a/include/osmocom/sgsn/vty.h
+++ b/include/osmocom/sgsn/vty.h
@@ -5,4 +5,5 @@
 enum bsc_vty_node {
 	SGSN_NODE = _LAST_OSMOVTY_NODE + 1,
 	GTPHUB_NODE,
+	MME_NODE,
 };
diff --git a/src/sgsn/Makefile.am b/src/sgsn/Makefile.am
index 8738986..9e4a342 100644
--- a/src/sgsn/Makefile.am
+++ b/src/sgsn/Makefile.am
@@ -53,6 +53,7 @@
 	gprs_sndcp_pcomp.c \
 	gprs_sndcp_vty.c \
 	gprs_sndcp_xid.c \
+	gtp_mme.c \
 	sgsn_main.c \
 	sgsn_vty.c \
 	sgsn_libgtp.c \
diff --git a/src/sgsn/gprs_sgsn.c b/src/sgsn/gprs_sgsn.c
index d4bc554..f744257 100644
--- a/src/sgsn/gprs_sgsn.c
+++ b/src/sgsn/gprs_sgsn.c
@@ -1042,6 +1042,8 @@
 	inst->cfg.auth_policy = SGSN_AUTH_POLICY_CLOSED;
 	inst->cfg.require_authentication = true; /* only applies if auth_policy is REMOTE */
 	inst->cfg.gsup_server_port = OSMO_GSUP_PORT;
+
+	INIT_LLIST_HEAD(&inst->mme_list);
 	return inst;
 }
 
diff --git a/src/sgsn/gtp_mme.c b/src/sgsn/gtp_mme.c
new file mode 100644
index 0000000..4fe804d
--- /dev/null
+++ b/src/sgsn/gtp_mme.c
@@ -0,0 +1,145 @@
+/* TS 29.060 § 7.5.14 RAN Information Management Messages */
+/*
+ * (C) 2021 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
+ * Author: Pau Espin Pedrol <pespin@sysmocom.de>
+ *
+ * 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/>.
+ */
+
+#include <talloc.h>
+
+#include <osmocom/sgsn/gtp_mme.h>
+#include <osmocom/sgsn/sgsn.h>
+
+extern void *tall_sgsn_ctx;
+
+static bool _eutran_tai_equal(const struct osmo_eutran_tai *t1, const struct osmo_eutran_tai *t2)
+{
+	return  t1->mcc == t2->mcc &&
+		t1->mnc == t2->mnc &&
+		t1->mnc_3_digits == t2->mnc_3_digits &&
+		t1->tac == t2->tac;
+}
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_alloc(struct sgsn_instance *sgsn, const char *name)
+{
+	struct sgsn_mme_ctx *mme;
+	mme = talloc_zero(tall_sgsn_ctx, struct sgsn_mme_ctx);
+	if (!mme)
+		return NULL;
+
+	/* if we are called from config file parse, this gsn doesn't exist yet */
+	mme->sgsn = sgsn;
+
+	mme->name = talloc_strdup(mme, name);
+
+	INIT_LLIST_HEAD(&mme->routes);
+	llist_add_tail(&mme->list, &sgsn->mme_list);
+
+	return mme;
+}
+
+void sgsn_mme_ctx_free(struct sgsn_mme_ctx *mme)
+{
+	struct mme_rim_route *rt, *rt2;
+	llist_del(&mme->list);
+
+	llist_for_each_entry_safe(rt, rt2, &mme->routes, list) {
+		llist_del(&rt->list);
+		talloc_free(rt);
+	}
+
+	talloc_free(mme);
+}
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_find_alloc(struct sgsn_instance *sgsn, const char *name)
+{
+	struct sgsn_mme_ctx *mme;
+
+	mme = sgsn_mme_ctx_by_name(sgsn, name);
+	if (!mme)
+		mme = sgsn_mme_ctx_alloc(sgsn, name);
+	return mme;
+}
+
+void sgsn_mme_ctx_route_add(struct sgsn_mme_ctx *mme, const struct osmo_eutran_tai *tai)
+{
+	struct mme_rim_route *rt = talloc_zero(mme, struct mme_rim_route);
+	rt->tai = *tai;
+	llist_add_tail(&rt->list, &mme->routes);
+}
+
+void sgsn_mme_ctx_route_del(struct sgsn_mme_ctx *mme, const struct osmo_eutran_tai *tai)
+{
+	struct mme_rim_route *rt;
+
+	llist_for_each_entry(rt, &mme->routes, list) {
+		if (_eutran_tai_equal(tai, &rt->tai)) {
+			llist_del(&rt->list);
+			talloc_free(rt);
+			return;
+		}
+	}
+}
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_name(const struct sgsn_instance *sgsn, const char *name)
+{
+	struct sgsn_mme_ctx *mme;
+
+	llist_for_each_entry(mme, &sgsn->mme_list, list) {
+		if (!strcmp(name, mme->name))
+			return mme;
+	}
+	return NULL;
+}
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_addr(const struct sgsn_instance *sgsn, const struct in_addr *addr)
+{
+	struct sgsn_mme_ctx *mme;
+
+	llist_for_each_entry(mme, &sgsn->mme_list, list) {
+		if (!memcmp(addr, &mme->remote_addr, sizeof(*addr)))
+			return mme;
+	}
+	return NULL;
+}
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_route(const struct sgsn_instance *sgsn, const struct osmo_eutran_tai *tai)
+{
+	struct sgsn_mme_ctx *mme;
+	llist_for_each_entry(mme, &sgsn->mme_list, list) {
+		struct mme_rim_route *rt;
+		llist_for_each_entry(rt, &mme->routes, list) {
+			if (_eutran_tai_equal(tai, &rt->tai)) {
+				return mme;
+			}
+		}
+	}
+	return NULL;
+}
+
+struct sgsn_mme_ctx *sgsn_mme_ctx_by_default_route(const struct sgsn_instance *sgsn)
+{
+	struct sgsn_mme_ctx *mme;
+
+	llist_for_each_entry(mme, &sgsn->mme_list, list) {
+		if (mme->default_route)
+			return mme;
+	}
+	return NULL;
+}
diff --git a/src/sgsn/sgsn_libgtp.c b/src/sgsn/sgsn_libgtp.c
index 8be7927..6229217 100644
--- a/src/sgsn/sgsn_libgtp.c
+++ b/src/sgsn/sgsn_libgtp.c
@@ -55,6 +55,8 @@
 #include <osmocom/sgsn/gprs_ranap.h>
 #include <osmocom/sgsn/gprs_gmm_fsm.h>
 #include <osmocom/sgsn/gprs_mm_state_gb_fsm.h>
+#include <osmocom/sgsn/gtp_mme.h>
+#include <osmocom/sgsn/sgsn_rim.h>
 
 #include <gtp.h>
 #include <pdp.h>
@@ -479,6 +481,43 @@
 	gtp_echo_req(ggc->gsn, ggc->gtp_version, ggc, &ggc->remote_addr);
 }
 
+int sgsn_mme_ran_info_req(struct sgsn_mme_ctx *mme, const struct bssgp_ran_information_pdu *pdu)
+{
+	char ri_src_str[64], ri_dest_str[64];
+	int ri_len;
+	struct msgb *msg;
+	struct bssgp_normal_hdr *bgph;
+	int rc;
+	uint8_t ri_buf[64];
+	uint8_t *ri_ptr = &ri_buf[0];
+	struct sockaddr_in sk_in = {
+		.sin_family = AF_INET,
+		.sin_port = htons(GTP1C_PORT),
+		.sin_addr = mme->remote_addr,
+	};
+
+	msg = bssgp_encode_rim_pdu(pdu);
+	if (!msg) {
+		LOGMME(mme, DRIM, LOGL_ERROR, "Tx GTP RAN Information Relay: failed to encode pdu\n");
+		return -EINVAL;
+	}
+	bgph = (struct bssgp_normal_hdr *)msgb_bssgph(msg);
+	DEBUGP(DLBSSGP, "Tx GTP RAN Information Relay: RIM-PDU:%s, src=%s, dest=%s\n",
+	       bssgp_pdu_str(bgph->pdu_type),
+	       bssgp_rim_ri_name_buf(ri_src_str, sizeof(ri_src_str), &pdu->routing_info_src),
+	       bssgp_rim_ri_name_buf(ri_dest_str, sizeof(ri_dest_str), &pdu->routing_info_dest));
+
+	if ((ri_len = bssgp_create_rim_ri(ri_ptr, &pdu->routing_info_dest)) < 0) {
+		ri_ptr = NULL;
+		ri_len = 0;
+	}
+
+	rc = gtp_ran_info_relay_req(mme->sgsn->gsn,  &sk_in, msgb_data(msg), msgb_length(msg),
+				    ri_ptr, ri_len, pdu->routing_info_dest.discr);
+	msgb_free(msg);
+	return rc;
+}
+
 /* Confirmation of a PDP Context Update */
 static int update_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 {
@@ -648,6 +687,42 @@
 	return 0;
 }
 
+static int cb_gtp_ran_info_relay_ind(struct sockaddr_in *peer, union gtpie_member **ie)
+{
+	char addrbuf[INET_ADDRSTRLEN];
+	struct sgsn_mme_ctx *mme = sgsn_mme_ctx_by_addr(sgsn, &peer->sin_addr);
+	if (!mme) {
+		LOGP(DGTP, LOGL_NOTICE, "Rx GTP RAN Information Relay from unknown MME %s\n",
+		     inet_ntop(AF_INET, &peer->sin_addr, addrbuf, sizeof(addrbuf)));
+		return -ECONNREFUSED;
+	}
+
+	LOGMME(mme, DGTP, LOGL_INFO, "Rx GTP RAN Information Relay\n");
+
+	unsigned int len = 0;
+	struct msgb *msg = msgb_alloc(4096, "gtpcv1_ran_info");
+	struct bssgp_ran_information_pdu pdu;
+
+	if (gtpie_gettlv(ie, GTPIE_RAN_T_CONTAIN, 0, &len, msgb_data(msg), 4096) || len <= 0) {
+		LOGMME(mme, DGTP, LOGL_ERROR, "Rx GTP RAN Information Relay: No Transparent Container IE found!\n");
+		goto ret_error;
+	}
+	msgb_put(msg, len);
+	msgb_bssgph(msg) = msg->data;
+	msgb_nsei(msg) = 0;
+	if (bssgp_parse_rim_pdu(&pdu, msg) < 0) {
+		LOGMME(mme, DGTP, LOGL_ERROR, "Rx GTP RAN Information Relay: Failed parsing Transparent Container IE!\n");
+		goto ret_error;
+	}
+
+	msgb_free(msg);
+	return sgsn_rim_rx_from_gtp(&pdu, mme);
+
+ret_error:
+	msgb_free(msg);
+	return -EINVAL;
+}
+
 /* Called whenever we receive a DATA packet */
 static int cb_data_ind(struct pdp_t *lib, void *packet, unsigned int len)
 {
@@ -837,6 +912,7 @@
 	gtp_set_cb_data_ind(gsn, cb_data_ind);
 	gtp_set_cb_unsup_ind(gsn, cb_unsup_ind);
 	gtp_set_cb_extheader_ind(gsn, cb_extheader_ind);
+	gtp_set_cb_ran_info_relay_ind(gsn, cb_gtp_ran_info_relay_ind);
 
 	return 0;
 }
diff --git a/src/sgsn/sgsn_main.c b/src/sgsn/sgsn_main.c
index 71f2efa..af9757a 100644
--- a/src/sgsn/sgsn_main.c
+++ b/src/sgsn/sgsn_main.c
@@ -122,7 +122,7 @@
 	case SAP_BSSGP_NM:
 		break;
 	case SAP_BSSGP_RIM:
-		return sgsn_rim_rx(bp, oph->msg);
+		return sgsn_rim_rx_from_gb(bp, oph->msg);
 	}
 	return 0;
 }
@@ -162,15 +162,36 @@
 	}
 }
 
+static int sgsn_vty_go_parent(struct vty *vty)
+{
+	switch (vty->node) {
+	case SGSN_NODE:
+		vty->node = CONFIG_NODE;
+		break;
+	case MME_NODE:
+		vty->node = SGSN_NODE;
+		vty->index = NULL;
+		break;
+	default:
+#if BUILD_IU
+		osmo_ss7_vty_go_parent(vty);
+#else
+		vty->node = CONFIG_NODE;
+		vty->index = NULL;
+#endif
+		break;
+	}
+
+	return vty->node;
+}
+
 /* NSI that BSSGP uses when transmitting on NS */
 extern struct gprs_ns_inst *bssgp_nsi;
 
 static struct vty_app_info vty_info = {
 	.name 		= "OsmoSGSN",
 	.version	= PACKAGE_VERSION,
-#if BUILD_IU
-	.go_parent_cb	= osmo_ss7_vty_go_parent,
-#endif
+	.go_parent_cb	= sgsn_vty_go_parent,
 };
 
 static void print_help(void)
diff --git a/src/sgsn/sgsn_rim.c b/src/sgsn/sgsn_rim.c
index 71e6d98..f28ba60 100644
--- a/src/sgsn/sgsn_rim.c
+++ b/src/sgsn/sgsn_rim.c
@@ -11,57 +11,113 @@
 #include <osmocom/gprs/gprs_bssgp.h>
 #include <osmocom/gprs/gprs_bssgp_rim.h>
 #include <osmocom/sgsn/sgsn_rim.h>
+#include <osmocom/sgsn/gtp_mme.h>
 #include <osmocom/sgsn/debug.h>
+#include <osmocom/sgsn/sgsn.h>
 
-/* Find an NSEI for the destination cell, this function works only for GERAN! */
-static int find_dest_nsei_geran(struct bssgp_rim_routing_info *dest_rim_ri, uint16_t nsei)
+static int sgsn_bssgp_fwd_rim_to_geran(const struct bssgp_ran_information_pdu *pdu)
 {
 	struct bssgp_bvc_ctx *bvc_ctx;
+	OSMO_ASSERT(pdu->routing_info_dest.discr == BSSGP_RIM_ROUTING_INFO_GERAN);
 
-	OSMO_ASSERT(dest_rim_ri->discr == BSSGP_RIM_ROUTING_INFO_GERAN);
-
-	bvc_ctx = btsctx_by_raid_cid(&dest_rim_ri->geran.raid, dest_rim_ri->geran.cid);
+	bvc_ctx = btsctx_by_raid_cid(&pdu->routing_info_dest.geran.raid, pdu->routing_info_dest.geran.cid);
 	if (!bvc_ctx) {
-		LOGP(DRIM, LOGL_ERROR, "BSSGP RIM (NSEI=%u) cannot find NSEI for destination cell\n", nsei);
+		LOGP(DRIM, LOGL_ERROR, "Unable to find NSEI for destination cell %s\n",
+		       bssgp_rim_ri_name(&pdu->routing_info_dest));
 		return -EINVAL;
 	}
 
-	return bvc_ctx->nsei;
+	/* Forward PDU as it is to the correct interface */
+	return bssgp_tx_rim(pdu, bvc_ctx->nsei);
 }
 
-int sgsn_rim_rx(struct osmo_bssgp_prim *bp, struct msgb *msg)
+static int sgsn_bssgp_fwd_rim_to_eutran(const struct bssgp_ran_information_pdu *pdu)
 {
-	struct bssgp_ran_information_pdu *pdu = &bp->u.rim_pdu;
-	int d_nsei;
-	uint16_t nsei = msgb_nsei(msg);
+	struct sgsn_mme_ctx *mme;
+	OSMO_ASSERT(pdu->routing_info_dest.discr == BSSGP_RIM_ROUTING_INFO_EUTRAN);
 
-	/* 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) {
-		LOGP(DRIM, LOGL_ERROR,
-		     "BSSGP RIM (NSEI=%u) only GERAN supported, destination cell is not a GERAN cell -- rejected.\n",
-		     nsei);
-		/* At the moment we can only handle GERAN addresses, any other
-		 * type of address will be consideres as an invalid address.
-		 * see also: 3GPP TS 48.018, section 8c.3.1.3 */
-		return bssgp_tx_status(BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
+	mme = sgsn_mme_ctx_by_route(sgsn, &pdu->routing_info_dest.eutran.tai);
+	if (!mme) { /* See if we have a default route configured */
+		mme = sgsn_mme_ctx_by_default_route(sgsn);
+		if (!mme) {
+			LOGP(DRIM, LOGL_ERROR, "Unable to find MME for destination cell %s\n",
+			       bssgp_rim_ri_name(&pdu->routing_info_dest));
+			return -EINVAL;
+		}
 	}
+
+	return sgsn_mme_ran_info_req(mme, pdu);
+}
+
+/* Receive a RIM PDU from BSSGP (GERAN) */
+int sgsn_rim_rx_from_gb(struct osmo_bssgp_prim *bp, struct msgb *msg)
+{
+	uint16_t nsei = msgb_nsei(msg);
+	struct bssgp_ran_information_pdu *pdu = &bp->u.rim_pdu;
+
 	if (pdu->routing_info_src.discr != BSSGP_RIM_ROUTING_INFO_GERAN) {
 		LOGP(DRIM, LOGL_ERROR,
-		     "BSSGP RIM (NSEI=%u) only GERAN supported, source cell is not a GERAN cell -- rejected.\n", nsei);
-		/* See comment above */
-		return bssgp_tx_status(BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
+		     "Rx BSSGP RIM (NSEI=%u): Expected src %s, got %s\n", nsei,
+		     bssgp_rim_routing_info_discr_str(BSSGP_RIM_ROUTING_INFO_GERAN),
+		     bssgp_rim_routing_info_discr_str(pdu->routing_info_src.discr));
+		goto err;
 	}
 
-	d_nsei = find_dest_nsei_geran(&pdu->routing_info_dest, nsei);
-	if (d_nsei < 0) {
-		LOGP(DRIM, LOGL_NOTICE, "BSSGP RIM (NSEI=%u) Cell %s unknown to this sgsn\n",
-		     nsei, bssgp_rim_ri_name(&pdu->routing_info_dest));
-		/* In case of an invalid destination address we respond with
-		 * a BSSGP STATUS PDU, see also: 3GPP TS 48.018, section 8c.3.1.3 */
-		return bssgp_tx_status(BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
+	switch (pdu->routing_info_dest.discr) {
+	case BSSGP_RIM_ROUTING_INFO_GERAN:
+		return sgsn_bssgp_fwd_rim_to_geran(pdu);
+	case BSSGP_RIM_ROUTING_INFO_EUTRAN:
+		return sgsn_bssgp_fwd_rim_to_eutran(pdu);
+	default:
+		/* At the moment we can only handle GERAN/EUTRAN addresses, any
+		 * other type of address will be considered as an invalid
+		 * address. see also: 3GPP TS 48.018, section 8c.3.1.3
+		 */
+		LOGP(DRIM, LOGL_ERROR,
+		     "Rx BSSGP RIM (NSEI=%u): Unsupported dst %s\n", nsei,
+		     bssgp_rim_routing_info_discr_str(pdu->routing_info_dest.discr));
 	}
 
-	/* Forward PDU as it is to the correct interface */
-	return bssgp_tx_rim(pdu, (uint16_t) d_nsei);
+	LOGP(DRIM, LOGL_INFO, "Rx BSSGP RIM (NSEI=%u): for dest cell %s\n", nsei,
+	     bssgp_rim_ri_name(&pdu->routing_info_dest));
+
+err:
+	/* In case of an invalid destination address we respond with
+	 * a BSSGP STATUS PDU, see also: 3GPP TS 48.018, section 8c.3.1.3 */
+	bssgp_tx_status(BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg);
+	return -1;
+}
+
+/* Receive a RIM PDU from GTPvC1 (EUTRAN) */
+int sgsn_rim_rx_from_gtp(struct bssgp_ran_information_pdu *pdu, struct sgsn_mme_ctx *mme)
+{
+	struct sgsn_mme_ctx *mme_tmp;
+	if (pdu->routing_info_src.discr != BSSGP_RIM_ROUTING_INFO_EUTRAN) {
+		LOGMME(mme, DRIM, LOGL_ERROR, "Rx GTP RAN Information Relay: Expected src %s, got %s\n",
+		       bssgp_rim_routing_info_discr_str(BSSGP_RIM_ROUTING_INFO_EUTRAN),
+		       bssgp_rim_routing_info_discr_str(pdu->routing_info_src.discr));
+		return -EINVAL;
+	}
+
+	if (pdu->routing_info_dest.discr != BSSGP_RIM_ROUTING_INFO_GERAN) {
+		LOGMME(mme, DRIM, LOGL_ERROR, "Rx GTP RAN Information Relay: Expected dst %s, got %s\n",
+		       bssgp_rim_routing_info_discr_str(BSSGP_RIM_ROUTING_INFO_GERAN),
+		       bssgp_rim_routing_info_discr_str(pdu->routing_info_dest.discr));
+		return -EINVAL;
+	}
+
+	mme_tmp = sgsn_mme_ctx_by_route(sgsn, &pdu->routing_info_src.eutran.tai);
+	if (!mme_tmp)/* See if we have a default route configured */
+		mme_tmp = sgsn_mme_ctx_by_default_route(sgsn);
+	if (mme != mme_tmp) {
+		LOGP(DRIM, LOGL_ERROR, "Rx GTP RAN Information Relay: "
+		     "Source MME doesn't have RIM routing configured for TAI: %s\n",
+		     bssgp_rim_ri_name(&pdu->routing_info_src));
+		return -EINVAL;
+	}
+
+	LOGMME(mme, DRIM, LOGL_INFO, "Rx GTP RAN Information Relay for dest cell %s\n",
+	       bssgp_rim_ri_name(&pdu->routing_info_dest));
+
+	return sgsn_bssgp_fwd_rim_to_geran(pdu);
 }
diff --git a/src/sgsn/sgsn_vty.c b/src/sgsn/sgsn_vty.c
index 042bad5..76d5202 100644
--- a/src/sgsn/sgsn_vty.c
+++ b/src/sgsn/sgsn_vty.c
@@ -37,6 +37,7 @@
 #include <osmocom/gprs/gprs_ns2.h>
 #include <osmocom/sgsn/gprs_gmm.h>
 #include <osmocom/sgsn/gprs_sgsn.h>
+#include <osmocom/sgsn/gtp_mme.h>
 #include <osmocom/sgsn/vty.h>
 #include <osmocom/gsupclient/gsup_client.h>
 
@@ -176,12 +177,35 @@
 	1,
 };
 
+static struct cmd_node mme_node = {
+	MME_NODE,
+	"%s(config-sgsn-mme)# ",
+	1,
+};
+
+static void config_write_mme(struct vty *vty, const struct sgsn_mme_ctx *mme, const char *prefix)
+{
+	struct mme_rim_route *rt;
+
+	vty_out(vty, "%smme %s%s", prefix, mme->name, VTY_NEWLINE);
+
+	vty_out(vty, "%s gtp remote-ip %s%s", prefix, inet_ntoa(mme->remote_addr), VTY_NEWLINE);
+	if (mme->default_route)
+		vty_out(vty, "%s gtp ran-info-relay default%s", prefix, VTY_NEWLINE);
+	llist_for_each_entry(rt, &mme->routes, list) {
+		vty_out(vty, "%s gtp ran-info-relay %s %s %u%s", prefix,
+			osmo_mcc_name(rt->tai.mcc), osmo_mnc_name(rt->tai.mnc, rt->tai.mnc_3_digits),
+			rt->tai.tac, VTY_NEWLINE);
+	}
+}
+
 static int config_write_sgsn(struct vty *vty)
 {
 	struct sgsn_ggsn_ctx *gctx;
 	struct imsi_acl_entry *acl;
 	struct apn_ctx *actx;
 	struct ares_addr_node *server;
+	struct sgsn_mme_ctx *mme;
 
 	vty_out(vty, "sgsn%s", VTY_NEWLINE);
 
@@ -296,6 +320,10 @@
 	} else
 		vty_out(vty, " no compression v42bis%s", VTY_NEWLINE);
 
+	llist_for_each_entry(mme, &sgsn->mme_list, list) {
+		config_write_mme(vty, mme, " ");
+	}
+
 #ifdef BUILD_IU
 	vty_out(vty, " cs7-instance-iu %u%s", g_cfg->iu.cs7_instance,
 		VTY_NEWLINE);
@@ -1423,6 +1451,161 @@
 }
 #endif
 
+DEFUN(cfg_sgsn_mme, cfg_sgsn_mme_cmd,
+	"mme NAME",
+	"Configure an MME peer\n"
+	"Name identifying the MME peer\n")
+{
+	struct sgsn_mme_ctx *mme;
+
+	mme = sgsn_mme_ctx_find_alloc(sgsn, argv[0]);
+	if (!mme)
+		return CMD_WARNING;
+
+	vty->node = MME_NODE;
+	vty->index = mme;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_sgsn_no_mme, cfg_sgsn_no_mme_cmd,
+	"no mme NAME",
+	NO_STR "Delete an MME peer configuration\n"
+	"Name identifying the MME peer\n")
+{
+	struct sgsn_mme_ctx *mme;
+
+	mme = sgsn_mme_ctx_by_name(sgsn, argv[0]);
+	if (!mme) {
+		vty_out(vty, "%% MME %s doesn't exist.%s",
+			argv[0], VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	sgsn_mme_ctx_free(mme);
+
+	return CMD_SUCCESS;
+}
+
+#define GTP_STR "Configure GTP connection\n"
+
+DEFUN(cfg_mme_remote_ip, cfg_mme_remote_ip_cmd,
+	"gtp remote-ip A.B.C.D",
+	GTP_STR "Set Remote GTP IP address\n" IP_STR)
+{
+	struct sgsn_mme_ctx *mme = (struct sgsn_mme_ctx *) vty->index;
+
+	inet_aton(argv[0], &mme->remote_addr);
+
+	return CMD_SUCCESS;
+}
+
+#define RAN_INFO_STR "Configure RAN Information Relay routing\n"
+#define TAI_DOC "MCC\n" "MNC\n" "TAC\n"
+
+DEFUN(cfg_mme_ran_info_relay_tai, cfg_mme_ran_info_relay_tai_cmd,
+	"gtp ran-info-relay <0-999> <0-999> <0-65535>",
+	GTP_STR RAN_INFO_STR TAI_DOC)
+{
+	struct sgsn_mme_ctx *mme = (struct sgsn_mme_ctx *) vty->index;
+	struct sgsn_mme_ctx *mme_tmp;
+	struct osmo_eutran_tai tai;
+
+	const char *mcc = argv[0];
+	const char *mnc = argv[1];
+	const char *tac = argv[2];
+
+	if (osmo_mcc_from_str(mcc, &tai.mcc)) {
+		vty_out(vty, "%% Error decoding MCC: %s%s", mcc, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	if (osmo_mnc_from_str(mnc, &tai.mnc, &tai.mnc_3_digits)) {
+		vty_out(vty, "%% Error decoding MNC: %s%s", mnc, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	tai.tac = atoi(tac);
+
+	if ((mme_tmp = sgsn_mme_ctx_by_route(sgsn, &tai))) {
+		if (mme_tmp != mme) {
+			vty_out(vty, "%% Another MME %s already contains this route%s",
+				mme_tmp->name, VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+		/* else: NO-OP, return */
+		return CMD_SUCCESS;
+	}
+
+	sgsn_mme_ctx_route_add(mme, &tai);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_mme_no_ran_info_relay_tai, cfg_mme_no_ran_info_relay_tai_cmd,
+	"no gtp ran-info-relay <0-999> <0-999> <0-65535>",
+	NO_STR GTP_STR RAN_INFO_STR TAI_DOC)
+{
+	struct sgsn_mme_ctx *mme = (struct sgsn_mme_ctx *) vty->index;
+	struct sgsn_mme_ctx *mme_tmp;
+	struct osmo_eutran_tai tai;
+
+	const char *mcc = argv[0];
+	const char *mnc = argv[1];
+	const char *tac = argv[2];
+
+	if (osmo_mcc_from_str(mcc, &tai.mcc)) {
+		vty_out(vty, "%% Error decoding MCC: %s%s", mcc, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	if (osmo_mnc_from_str(mnc, &tai.mnc, &tai.mnc_3_digits)) {
+		vty_out(vty, "%% Error decoding MNC: %s%s", mnc, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	tai.tac = atoi(tac);
+
+	if ((mme_tmp = sgsn_mme_ctx_by_route(sgsn, &tai))) {
+		if (mme_tmp != mme) {
+			vty_out(vty, "%% Another MME %s contains this route%s",
+				mme_tmp->name, VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+		sgsn_mme_ctx_route_del(mme, &tai);
+		return CMD_SUCCESS;
+	} else {
+		vty_out(vty, "%% This route doesn't exist in current MME %s%s",
+			mme->name, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+}
+
+DEFUN(cfg_mme_ran_info_relay_default, cfg_mme_ran_info_relay_default_cmd,
+	"gtp ran-info-relay default",
+	GTP_STR RAN_INFO_STR "Set as default route")
+{
+	struct sgsn_mme_ctx *mme = (struct sgsn_mme_ctx *) vty->index;
+	struct sgsn_mme_ctx *default_mme;
+
+	if (mme->default_route)
+		return CMD_SUCCESS; /* NO-OP */
+
+	if ((default_mme = sgsn_mme_ctx_by_default_route(sgsn))) {
+		vty_out(vty, "%% Another MME %s is already set as default route, "
+			     "remove it before setting it here.%s",
+			     default_mme->name, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	mme->default_route = true;
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_mme_no_ran_info_relay_default, cfg_mme_no_ran_info_relay_default_cmd,
+	"no gtp ran-info-relay default",
+	NO_STR GTP_STR RAN_INFO_STR "Set as default route")
+{
+	struct sgsn_mme_ctx *mme = (struct sgsn_mme_ctx *) vty->index;
+	mme->default_route = false;
+	return CMD_SUCCESS;
+}
+
 int sgsn_vty_init(struct sgsn_config *cfg)
 {
 	g_cfg = cfg;
@@ -1486,6 +1669,15 @@
 	install_element(SGSN_NODE, &cfg_comp_v42bis_cmd);
 	install_element(SGSN_NODE, &cfg_comp_v42bisp_cmd);
 
+	install_element(SGSN_NODE, &cfg_sgsn_mme_cmd);
+	install_element(SGSN_NODE, &cfg_sgsn_no_mme_cmd);
+	install_node(&mme_node, NULL);
+	install_element(MME_NODE, &cfg_mme_remote_ip_cmd);
+	install_element(MME_NODE, &cfg_mme_ran_info_relay_default_cmd);
+	install_element(MME_NODE, &cfg_mme_no_ran_info_relay_default_cmd);
+	install_element(MME_NODE, &cfg_mme_ran_info_relay_tai_cmd);
+	install_element(MME_NODE, &cfg_mme_no_ran_info_relay_tai_cmd);
+
 #ifdef BUILD_IU
 	install_element(SGSN_NODE, &cfg_sgsn_cs7_instance_iu_cmd);
 	ranap_iu_vty_init(SGSN_NODE, &g_cfg->iu.rab_assign_addr_enc);
diff --git a/tests/osmo-sgsn_test-nodes.vty b/tests/osmo-sgsn_test-nodes.vty
index 953a30e..f889541 100644
--- a/tests/osmo-sgsn_test-nodes.vty
+++ b/tests/osmo-sgsn_test-nodes.vty
@@ -61,3 +61,58 @@
   compression v42bis active direction (ms|sgsn|both) codewords <512-65535> strlen <6-250>
   compression v42bis passive
 ...
+
+OsmoSGSN(config-sgsn)# mme test0
+OsmoSGSN(config-sgsn-mme)# gtp remote-ip 1.2.3.4
+OsmoSGSN(config-sgsn-mme)# gtp ran-info-relay 907 10 567
+OsmoSGSN(config-sgsn-mme)# gtp ran-info-relay 202 12 51
+OsmoSGSN(config-sgsn-mme)# gtp ran-info-relay 907 10 567
+OsmoSGSN(config-sgsn-mme)# exit
+OsmoSGSN(config-sgsn)# mme test1
+OsmoSGSN(config-sgsn-mme)# gtp remote-ip 5.6.7.8
+OsmoSGSN(config-sgsn-mme)# gtp ran-info-relay default
+OsmoSGSN(config-sgsn-mme)# exit
+OsmoSGSN(config-sgsn)# show running-config
+...
+sgsn
+...
+ mme test0
+  gtp remote-ip 1.2.3.4
+  gtp ran-info-relay 907 10 567
+  gtp ran-info-relay 202 12 51
+ mme test1
+  gtp remote-ip 5.6.7.8
+  gtp ran-info-relay default
+...
+OsmoSGSN(config-sgsn)# mme test0
+OsmoSGSN(config-sgsn-mme)# gtp ran-info-relay default
+% Another MME test1 is already set as default route, remove it before setting it here.
+OsmoSGSN(config-sgsn-mme)# exit
+OsmoSGSN(config-sgsn)# mme test1
+OsmoSGSN(config-sgsn-mme)# no gtp ran-info-relay default
+OsmoSGSN(config-sgsn-mme)# exit
+OsmoSGSN(config-sgsn)# mme test0
+OsmoSGSN(config-sgsn-mme)# gtp ran-info-relay default
+OsmoSGSN(config-sgsn-mme)# exit
+OsmoSGSN(config-sgsn)# show running-config
+...
+sgsn
+...
+ mme test0
+  gtp remote-ip 1.2.3.4
+  gtp ran-info-relay default
+  gtp ran-info-relay 907 10 567
+  gtp ran-info-relay 202 12 51
+ mme test1
+  gtp remote-ip 5.6.7.8
+...
+OsmoSGSN(config-sgsn)# no mme test0
+OsmoSGSN(config-sgsn)# show running-config
+...
+sgsn
+...
+ no compression v42bis
+ mme test1
+  gtp remote-ip 5.6.7.8
+...
+OsmoSGSN(config-sgsn)# no mme test1
diff --git a/tests/sgsn/Makefile.am b/tests/sgsn/Makefile.am
index b72c446..bdf941d 100644
--- a/tests/sgsn/Makefile.am
+++ b/tests/sgsn/Makefile.am
@@ -50,6 +50,7 @@
 	$(top_builddir)/src/sgsn/gprs_gmm_fsm.o \
 	$(top_builddir)/src/sgsn/gprs_mm_state_gb_fsm.o \
 	$(top_builddir)/src/sgsn/gprs_sgsn.o \
+	$(top_builddir)/src/sgsn/gtp_mme.o \
 	$(top_builddir)/src/sgsn/sgsn_vty.o \
 	$(top_builddir)/src/sgsn/sgsn_libgtp.o \
 	$(top_builddir)/src/sgsn/sgsn_auth.o \
@@ -62,6 +63,7 @@
         $(top_builddir)/src/sgsn/gprs_sndcp_pcomp.o \
         $(top_builddir)/src/sgsn/v42bis.o \
         $(top_builddir)/src/sgsn/gprs_sndcp_dcomp.o \
+	$(top_builddir)/src/sgsn/sgsn_rim.o \
 	$(top_builddir)/src/gprs/gprs_utils.o \
 	$(top_builddir)/src/gprs/gprs_llc_parse.o \
 	$(top_builddir)/src/gprs/gprs_gb_parse.o \