diff --git a/libgtnl/include/libgtpnl/gtp.h b/libgtnl/include/libgtpnl/gtp.h
index fa09d2a..521339d 100644
--- a/libgtnl/include/libgtpnl/gtp.h
+++ b/libgtnl/include/libgtpnl/gtp.h
@@ -14,6 +14,8 @@ void gtp_tunnel_set_ms_ip4(struct gtp_tunnel *t, struct in_addr *ms_addr);
 void gtp_tunnel_set_sgsn_ip4(struct gtp_tunnel *t, struct in_addr *sgsn_addr);
 void gtp_tunnel_set_version(struct gtp_tunnel *t, uint32_t version);
 void gtp_tunnel_set_tid(struct gtp_tunnel *t, uint64_t tid);
+void gtp_tunnel_set_i_tei(struct gtp_tunnel *t, uint32_t i_tei);
+void gtp_tunnel_set_o_tei(struct gtp_tunnel *t, uint32_t o_tei);
 void gtp_tunnel_set_flowid(struct gtp_tunnel *t, uint16_t flowid);
 
 const int gtp_tunnel_get_ifns(struct gtp_tunnel *t);
@@ -22,6 +24,8 @@ const struct in_addr *gtp_tunnel_get_ms_ip4(struct gtp_tunnel *t);
 const struct in_addr *gtp_tunnel_get_sgsn_ip4(struct gtp_tunnel *t);
 int gtp_tunnel_get_version(struct gtp_tunnel *t);
 uint64_t gtp_tunnel_get_tid(struct gtp_tunnel *t);
+uint32_t gtp_tunnel_get_i_tei(struct gtp_tunnel *t);
+uint32_t gtp_tunnel_get_o_tei(struct gtp_tunnel *t);
 uint16_t gtp_tunnel_get_flowid(struct gtp_tunnel *t);
 
 #endif
diff --git a/libgtnl/include/linux/gtp_nl.h b/libgtnl/include/linux/gtp_nl.h
index a1e8ce1..deb92cf 100644
--- a/libgtnl/include/linux/gtp_nl.h
+++ b/libgtnl/include/linux/gtp_nl.h
@@ -41,6 +41,8 @@ enum gtp_attrs {
 	GTPA_MS_ADDRESS,
 	GTPA_FLOW,	/* only for GTPv0 */
 	GTPA_NET_NS_FD,
+	GTPA_I_TEI,
+	GTPA_O_TEI,
 	__GTPA_MAX,
 };
 #define GTPA_MAX (__GTPA_MAX + 1)
diff --git a/libgtnl/src/gtp-genl.c b/libgtnl/src/gtp-genl.c
index ddb7cc7..3c7deed 100644
--- a/libgtnl/src/gtp-genl.c
+++ b/libgtnl/src/gtp-genl.c
@@ -49,8 +49,13 @@ static void gtp_build_payload(struct nlmsghdr *nlh, struct gtp_tunnel *t)
 	mnl_attr_put_u32(nlh, GTPA_LINK, t->ifidx);
 	mnl_attr_put_u32(nlh, GTPA_SGSN_ADDRESS, t->sgsn_addr.s_addr);
 	mnl_attr_put_u32(nlh, GTPA_MS_ADDRESS, t->ms_addr.s_addr);
-	mnl_attr_put_u64(nlh, GTPA_TID, t->tid);
-	mnl_attr_put_u16(nlh, GTPA_FLOW, t->flowid);
+	if (t->gtp_version == GTP_V0) {
+		mnl_attr_put_u64(nlh, GTPA_TID, t->u.v0.tid);
+		mnl_attr_put_u16(nlh, GTPA_FLOW, t->u.v0.flowid);
+	} else if (t->gtp_version == GTP_V1) {
+		mnl_attr_put_u32(nlh, GTPA_I_TEI, t->u.v1.i_tei);
+		mnl_attr_put_u32(nlh, GTPA_O_TEI, t->u.v1.o_tei);
+	}
 }
 
 int gtp_add_tunnel(int genl_id, struct mnl_socket *nl, struct gtp_tunnel *t)
@@ -95,7 +100,15 @@ EXPORT_SYMBOL(gtp_del_tunnel);
 
 struct gtp_pdp {
 	uint32_t	version;
-	uint64_t	tid;
+	union {
+		struct {
+			uint64_t tid;
+		} v0;
+		struct {
+			uint32_t i_tei;
+			uint32_t o_tei;
+		} v1;
+	} u;
 	struct in_addr	sgsn_addr;
 	struct in_addr	ms_addr;
 };
@@ -115,6 +128,8 @@ static int genl_gtp_validate_cb(const struct nlattr *attr, void *data)
 			return MNL_CB_ERROR;
 		}
 		break;
+	case GTPA_O_TEI:
+	case GTPA_I_TEI:
 	case GTPA_SGSN_ADDRESS:
 	case GTPA_MS_ADDRESS:
 	case GTPA_VERSION:
@@ -138,7 +153,11 @@ static int genl_gtp_attr_cb(const struct nlmsghdr *nlh, void *data)
 
 	mnl_attr_parse(nlh, sizeof(*genl), genl_gtp_validate_cb, tb);
 	if (tb[GTPA_TID])
-		pdp.tid = mnl_attr_get_u64(tb[GTPA_TID]);
+		pdp.u.v0.tid = mnl_attr_get_u64(tb[GTPA_TID]);
+	if (tb[GTPA_I_TEI])
+		pdp.u.v1.i_tei = mnl_attr_get_u32(tb[GTPA_I_TEI]);
+	if (tb[GTPA_O_TEI])
+		pdp.u.v1.o_tei = mnl_attr_get_u32(tb[GTPA_O_TEI]);
 	if (tb[GTPA_SGSN_ADDRESS]) {
 		pdp.sgsn_addr.s_addr =
 			mnl_attr_get_u32(tb[GTPA_SGSN_ADDRESS]);
@@ -151,7 +170,12 @@ static int genl_gtp_attr_cb(const struct nlmsghdr *nlh, void *data)
 	}
 
 	printf("version %u ", pdp.version);
-	printf("tid %"PRIu64" ms_addr %s ", pdp.tid, inet_ntoa(pdp.sgsn_addr));
+	if (pdp.version == GTP_V0)
+		printf("tid %"PRIu64" ms_addr %s ",
+		       pdp.u.v0.tid, inet_ntoa(pdp.sgsn_addr));
+	else if (pdp.version == GTP_V1)
+		printf("tei %u/%u ms_addr %s ", pdp.u.v1.i_tei,
+		       pdp.u.v1.o_tei, inet_ntoa(pdp.sgsn_addr));
 	printf("sgsn_addr %s\n", inet_ntoa(pdp.ms_addr));
 
 	return MNL_CB_OK;
diff --git a/libgtnl/src/gtp.c b/libgtnl/src/gtp.c
index 6e3d473..bb5eaaf 100644
--- a/libgtnl/src/gtp.c
+++ b/libgtnl/src/gtp.c
@@ -71,16 +71,28 @@ EXPORT_SYMBOL(gtp_tunnel_set_version);
 
 void gtp_tunnel_set_tid(struct gtp_tunnel *t, uint64_t tid)
 {
-	t->tid = tid;
+	t->u.v0.tid = tid;
 }
 EXPORT_SYMBOL(gtp_tunnel_set_tid);
 
 void gtp_tunnel_set_flowid(struct gtp_tunnel *t, uint16_t flowid)
 {
-	t->flowid = flowid;
+	t->u.v0.flowid = flowid;
 }
 EXPORT_SYMBOL(gtp_tunnel_set_flowid);
 
+void gtp_tunnel_set_i_tei(struct gtp_tunnel *t, uint32_t i_tei)
+{
+	t->u.v1.i_tei = i_tei;
+}
+EXPORT_SYMBOL(gtp_tunnel_set_i_tei);
+
+void gtp_tunnel_set_o_tei(struct gtp_tunnel *t, uint32_t o_tei)
+{
+	t->u.v1.o_tei = o_tei;
+}
+EXPORT_SYMBOL(gtp_tunnel_set_o_tei);
+
 const int gtp_tunnel_get_ifns(struct gtp_tunnel *t)
 {
 	return t->ifns;
@@ -113,12 +125,24 @@ EXPORT_SYMBOL(gtp_tunnel_get_version);
 
 uint64_t gtp_tunnel_get_tid(struct gtp_tunnel *t)
 {
-	return t->tid;
+	return t->u.v0.tid;
 }
 EXPORT_SYMBOL(gtp_tunnel_get_tid);
 
 uint16_t gtp_tunnel_get_flowid(struct gtp_tunnel *t)
 {
-	return t->flowid;
+	return t->u.v0.flowid;
 }
 EXPORT_SYMBOL(gtp_tunnel_get_flowid);
+
+uint32_t gtp_tunnel_get_i_tei(struct gtp_tunnel *t)
+{
+	return t->u.v1.i_tei;
+}
+EXPORT_SYMBOL(gtp_tunnel_get_i_tei);
+
+uint32_t gtp_tunnel_get_o_tei(struct gtp_tunnel *t)
+{
+	return t->u.v1.o_tei;
+}
+EXPORT_SYMBOL(gtp_tunnel_get_o_tei);
diff --git a/libgtnl/src/internal.h b/libgtnl/src/internal.h
index 68f0135..1754e3b 100644
--- a/libgtnl/src/internal.h
+++ b/libgtnl/src/internal.h
@@ -17,9 +17,17 @@ struct gtp_tunnel {
 	uint32_t	ifidx;
 	struct in_addr	ms_addr;
 	struct in_addr	sgsn_addr;
-	uint64_t	tid;
-	uint16_t	flowid;
 	int		gtp_version;
+	union {
+		struct {
+			uint64_t tid;
+			uint16_t flowid;
+		} v0;
+		struct {
+			uint32_t i_tei;
+			uint32_t o_tei;
+		} v1;
+	} u;
 };
 
 #endif
diff --git a/libgtnl/src/libgtpnl.map b/libgtnl/src/libgtpnl.map
index 2368467..9ca83c7 100644
--- a/libgtnl/src/libgtpnl.map
+++ b/libgtnl/src/libgtpnl.map
@@ -22,6 +22,8 @@ global:
   gtp_tunnel_set_version;
   gtp_tunnel_set_tid;
   gtp_tunnel_set_flowid;
+  gtp_tunnel_set_i_tei;
+  gtp_tunnel_set_o_tei;
   gtp_tunnel_get_ifns;
   gtp_tunnel_get_ifidx;
   gtp_tunnel_get_ms_ip4;
@@ -29,6 +31,8 @@ global:
   gtp_tunnel_get_version;
   gtp_tunnel_get_tid;
   gtp_tunnel_get_flowid;
+  gtp_tunnel_get_i_tei;
+  gtp_tunnel_get_o_tei;
 
 local: *;
 };
diff --git a/libgtnl/tools/Makefile.am b/libgtnl/tools/Makefile.am
index 7880f3c..89dca32 100644
--- a/libgtnl/tools/Makefile.am
+++ b/libgtnl/tools/Makefile.am
@@ -3,8 +3,8 @@ include $(top_srcdir)/Make_global.am
 check_PROGRAMS = gtp-link-add		\
 		 gtp-tunnel
 
-gtp_link_add_SOURCES = gtp-link-add.c gtpnl.c
+gtp_link_add_SOURCES = gtp-link-add.c
 gtp_link_add_LDADD = ../src/libgtpnl.la ${LIBMNL_LIBS}
 
-gtp_tunnel_SOURCES = gtp-tunnel.c gtpnl.c
+gtp_tunnel_SOURCES = gtp-tunnel.c
 gtp_tunnel_LDADD = ../src/libgtpnl.la ${LIBMNL_LIBS}
diff --git a/libgtnl/tools/gtp-tunnel.c b/libgtnl/tools/gtp-tunnel.c
index 9c52a27..bb12c3f 100644
--- a/libgtnl/tools/gtp-tunnel.c
+++ b/libgtnl/tools/gtp-tunnel.c
@@ -28,71 +28,91 @@
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <net/if.h>
+#include <inttypes.h>
 
 #include <libmnl/libmnl.h>
 #include <linux/genetlink.h>
 
 #include <linux/gtp_nl.h>
+#include <libgtpnl/gtp.h>
 #include <libgtpnl/gtpnl.h>
 
+static void add_usage(const char *name)
+{
+	printf("%s add <gtp device> <v0> <tid> <ms-addr> <sgsn-addr>\n",
+	       name);
+	printf("%s add <gtp device> <v1> <i_tei> <o_tei> <ms-addr> <sgsn-addr>\n",
+	       name);
+}
+
 static int
 add_tunnel(int argc, char *argv[], int genl_id, struct mnl_socket *nl)
 {
+	struct gtp_tunnel *t;
 	uint32_t gtp_ifidx;
 	struct in_addr ms, sgsn;
-	struct nlmsghdr *nlh;
-	char buf[MNL_SOCKET_BUFFER_SIZE];
-	uint32_t seq = time(NULL), gtp_version;
+	uint32_t gtp_version;
+	int optidx;
 
-	if (argc != 7) {
-		printf("%s add <gtp device> <v0|v1> <tid> <ms-addr> <sgsn-addr>\n",
-			argv[0]);
+	if (argc < 7 || argc > 8) {
+		add_usage(argv[0]);
 		return EXIT_FAILURE;
 	}
-	gtp_ifidx = if_nametoindex(argv[2]);
+
+	t = gtp_tunnel_alloc();
+	optidx = 2;
+
+	gtp_ifidx = if_nametoindex(argv[optidx]);
 	if (gtp_ifidx == 0) {
-		fprintf(stderr, "wrong GTP interface %s\n", argv[2]);
+		fprintf(stderr, "wrong GTP interface %s\n", argv[optidx]);
 		return EXIT_FAILURE;
 	}
+	gtp_tunnel_set_ifidx(t, gtp_ifidx);
 
-	if (inet_aton(argv[5], &ms) < 0) {
-		perror("bad address for ms");
-		exit(EXIT_FAILURE);
-	}
-
-	if (inet_aton(argv[6], &sgsn) < 0) {
-		perror("bad address for sgsn");
-		exit(EXIT_FAILURE);
-	}
+	optidx++;
 
-	if (strcmp(argv[3], "v0") == 0)
+	if (strcmp(argv[optidx], "v0") == 0)
 		gtp_version = GTP_V0;
-	else if (strcmp(argv[3], "v1") == 0)
+	else if (strcmp(argv[optidx], "v1") == 0)
 		gtp_version = GTP_V1;
 	else {
 		fprintf(stderr, "wrong GTP version %s, use v0 or v1\n",
-			argv[3]);
+			argv[optidx]);
 		return EXIT_FAILURE;
 	}
+	gtp_tunnel_set_version(t, gtp_version);
 
-	nlh = genl_nlmsg_build_hdr(buf, genl_id, NLM_F_EXCL | NLM_F_ACK, ++seq,
-				   GTP_CMD_TUNNEL_NEW);
-	gtp_build_payload(nlh, atoi(argv[4]), gtp_ifidx, sgsn.s_addr,
-			  ms.s_addr, gtp_version);
+	if (gtp_version == GTP_V0)
+		gtp_tunnel_set_tid(t, atoi(argv[optidx++]));
+	else if (gtp_version == GTP_V1) {
+		gtp_tunnel_set_i_tei(t, atoi(argv[optidx++]));
+		gtp_tunnel_set_o_tei(t, atoi(argv[optidx++]));
+	}
 
-	if (genl_socket_talk(nl, nlh, seq, NULL, NULL) < 0)
-		perror("genl_socket_talk");
+	if (inet_aton(argv[optidx++], &ms) < 0) {
+		perror("bad address for ms");
+		exit(EXIT_FAILURE);
+	}
+	gtp_tunnel_set_ms_ip4(t, &ms);
+
+	if (inet_aton(argv[optidx++], &sgsn) < 0) {
+		perror("bad address for sgsn");
+		exit(EXIT_FAILURE);
+	}
+	gtp_tunnel_set_sgsn_ip4(t, &sgsn);
+
+	gtp_add_tunnel(genl_id, nl, t);
 
+	gtp_tunnel_free(t);
 	return 0;
 }
 
 static int
 del_tunnel(int argc, char *argv[], int genl_id, struct mnl_socket *nl)
 {
+	struct gtp_tunnel *t;
 	uint32_t gtp_ifidx;
-	char buf[MNL_SOCKET_BUFFER_SIZE];
-	struct nlmsghdr *nlh;
-	uint32_t seq = time(NULL);
 
 	if (argc != 5) {
 		printf("%s add <gtp device> <version> <tid>\n",
@@ -100,21 +120,44 @@ del_tunnel(int argc, char *argv[], int genl_id, struct mnl_socket *nl)
 		return EXIT_FAILURE;
 	}
 
-	gtp_ifidx = if_nametoindex(argv[2]);
+	t = gtp_tunnel_alloc();
 
-	nlh = genl_nlmsg_build_hdr(buf, genl_id, NLM_F_ACK, ++seq,
-				   GTP_CMD_TUNNEL_DELETE);
-	gtp_build_payload(nlh, atoi(argv[4]), gtp_ifidx, 0, 0, atoi(argv[3]));
+	gtp_ifidx = if_nametoindex(argv[2]);
+	if (gtp_ifidx == 0) {
+		fprintf(stderr, "wrong GTP interface %s\n", argv[2]);
+		return EXIT_FAILURE;
+	}
+	gtp_tunnel_set_ifidx(t, gtp_ifidx);
+
+	if (strcmp(argv[3], "v0") == 0) {
+		gtp_tunnel_set_version(t, GTP_V0);
+		gtp_tunnel_set_tid(t, atoi(argv[4]));
+	} else if (strcmp(argv[3], "v1") == 0) {
+		gtp_tunnel_set_version(t, GTP_V1);
+		gtp_tunnel_set_i_tei(t, atoi(argv[4]));
+	} else {
+		fprintf(stderr, "wrong GTP version %s, use v0 or v1\n",
+			argv[3]);
+		return EXIT_FAILURE;
+	}
 
-	if (genl_socket_talk(nl, nlh, seq, NULL, NULL) < 0)
-		perror("genl_socket_talk");
+	gtp_del_tunnel(genl_id, nl, t);
 
+	gtp_tunnel_free(t);
 	return 0;
 }
 
 struct gtp_pdp {
 	uint32_t	version;
-	uint64_t	tid;
+	union {
+		struct {
+			uint64_t tid;
+		} v0;
+		struct {
+			uint32_t i_tei;
+			uint32_t o_tei;
+		} v1;
+	} u;
 	struct in_addr	sgsn_addr;
 	struct in_addr	ms_addr;
 };
@@ -134,6 +177,8 @@ static int genl_gtp_validate_cb(const struct nlattr *attr, void *data)
 			return MNL_CB_ERROR;
 		}
 		break;
+	case GTPA_I_TEI:
+	case GTPA_O_TEI:
 	case GTPA_SGSN_ADDRESS:
 	case GTPA_MS_ADDRESS:
 	case GTPA_VERSION:
@@ -152,12 +197,16 @@ static int genl_gtp_validate_cb(const struct nlattr *attr, void *data)
 static int genl_gtp_attr_cb(const struct nlmsghdr *nlh, void *data)
 {
 	struct nlattr *tb[GTPA_MAX + 1] = {};
-	struct gtp_pdp pdp;
+	struct gtp_pdp pdp = {};
 	struct genlmsghdr *genl;
 
 	mnl_attr_parse(nlh, sizeof(*genl), genl_gtp_validate_cb, tb);
 	if (tb[GTPA_TID])
-		pdp.tid = mnl_attr_get_u64(tb[GTPA_TID]);
+		pdp.u.v0.tid = mnl_attr_get_u64(tb[GTPA_TID]);
+	if (tb[GTPA_I_TEI])
+		pdp.u.v1.i_tei = mnl_attr_get_u32(tb[GTPA_I_TEI]);
+	if (tb[GTPA_O_TEI])
+		pdp.u.v1.o_tei = mnl_attr_get_u32(tb[GTPA_O_TEI]);
 	if (tb[GTPA_SGSN_ADDRESS]) {
 		pdp.sgsn_addr.s_addr =
 			mnl_attr_get_u32(tb[GTPA_SGSN_ADDRESS]);
@@ -170,7 +219,12 @@ static int genl_gtp_attr_cb(const struct nlmsghdr *nlh, void *data)
 	}
 
 	printf("version %u ", pdp.version);
-	printf("tid %llx ms_addr %s ", pdp.tid, inet_ntoa(pdp.ms_addr));
+	if (pdp.version == GTP_V0)
+		printf("tid %"PRIu64" ms_addr %s ",
+		       pdp.u.v0.tid, inet_ntoa(pdp.sgsn_addr));
+	else if (pdp.version == GTP_V1)
+		printf("tei %u/%u ms_addr %s ", pdp.u.v1.i_tei,
+		       pdp.u.v1.o_tei, inet_ntoa(pdp.sgsn_addr));
 	printf("sgsn_addr %s\n", inet_ntoa(pdp.sgsn_addr));
 
 	return MNL_CB_OK;
@@ -197,8 +251,6 @@ list_tunnel(int argc, char *argv[], int genl_id, struct mnl_socket *nl)
 int main(int argc, char *argv[])
 {
 	struct mnl_socket *nl;
-	char buf[MNL_SOCKET_BUFFER_SIZE];
-	unsigned int portid;
 	int32_t genl_id;
 	int ret;
 
diff --git a/libgtnl/tools/gtpnl.c b/libgtnl/tools/gtpnl.c
deleted file mode 100644
index 252f0b1..0000000
--- a/libgtnl/tools/gtpnl.c
+++ /dev/null
@@ -1,35 +0,0 @@
-/* Helper functions */
-
-/* (C) 2014 by sysmocom - s.f.m.c. GmbH
- * Author: Pablo Neira Ayuso <pablo@gnumonks.org>
- *
- * All Rights Reserved
- *
- * 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-#include <stdint.h>
-#include <libmnl/libmnl.h>
-#include <linux/gtp_nl.h>
-
-void gtp_build_payload(struct nlmsghdr *nlh, uint64_t tid, uint32_t ifidx,
-		       uint32_t sgsn_addr, uint32_t ms_addr, uint32_t version)
-{
-	mnl_attr_put_u32(nlh, GTPA_VERSION, version);
-	mnl_attr_put_u32(nlh, GTPA_LINK, ifidx);
-	mnl_attr_put_u32(nlh, GTPA_SGSN_ADDRESS, sgsn_addr);
-	mnl_attr_put_u32(nlh, GTPA_MS_ADDRESS, ms_addr);
-	mnl_attr_put_u64(nlh, GTPA_TID, tid);
-}
