diff --git a/Makefile.am b/Makefile.am
index fcf6771b..6d0f3be9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -42,7 +42,7 @@ gdbus_sources = gdbus/gdbus.h gdbus/mainloop.c gdbus/object.c gdbus/watch.c
 gisi_sources = gisi/phonet.h gisi/modem.h gisi/netlink.h gisi/netlink.c \
 		gisi/socket.h gisi/socket.c gisi/client.h gisi/client.c \
 		gisi/pep.h gisi/pep.c gisi/pipe.h gisi/pipe.c gisi/iter.h \
-		gisi/iter.c
+		gisi/iter.c gisi/verify.c
 
 gatchat_sources = gatchat/gatchat.h gatchat/gatchat.c \
 				gatchat/gatresult.h gatchat/gatresult.c \
diff --git a/gisi/client.c b/gisi/client.c
index b3f685be..c592c3c9 100644
--- a/gisi/client.c
+++ b/gisi/client.c
@@ -41,6 +41,10 @@
 
 struct _GIsiClient {
 	uint8_t resource;
+	struct {
+		int major;
+		int minor;
+	} version;
 	GIsiModem *modem;
 
 	/* Requests */
@@ -100,6 +104,8 @@ GIsiClient *g_isi_client_create(GIsiModem *modem, uint8_t resource)
 		abort();
 	cl = ptr;
 	cl->resource = resource;
+	cl->version.major = -1;
+	cl->version.minor = -1;
 	cl->modem = modem;
 	cl->debug_func = NULL;
 	memset(cl->timeout, 0, sizeof(cl->timeout));
@@ -132,6 +138,43 @@ GIsiClient *g_isi_client_create(GIsiModem *modem, uint8_t resource)
 	return cl;
 }
 
+/**
+ * Set the ISI resource version of @a client.
+ * @param client client for the resource
+ * @param major ISI major version
+ * @param minor ISI minor version
+ */
+void g_isi_version_set(GIsiClient *client, int major, int minor)
+{
+	if (!client)
+		return;
+
+	client->version.major = major;
+	client->version.minor = minor;
+}
+
+/**
+ * Returns the ISI major version of the resource associated with @a
+ * client.
+ * @param client client for the resource
+ * @return major version, -1 if not available
+ */
+int g_isi_version_major(GIsiClient *client)
+{
+	return client->version.major;
+}
+
+/**
+ * Returns the ISI minor version of the resource associated with @a
+ * client.
+ * @param client client for the resource
+ * @return minor version, -1 if not available
+ */
+int g_isi_version_minor(GIsiClient *client)
+{
+	return client->version.minor;
+}
+
 /**
  * Returns the resource associated with @a client
  * @param client client for the resource
diff --git a/gisi/client.h b/gisi/client.h
index 448f9e5c..d0c0c4b5 100644
--- a/gisi/client.h
+++ b/gisi/client.h
@@ -38,6 +38,8 @@ typedef struct _GIsiClient GIsiClient;
 struct _GIsiRequest;
 typedef struct _GIsiRequest GIsiRequest;
 
+typedef void (*GIsiVerifyFunc)(GIsiClient *client, bool alive, void *opaque);
+
 typedef bool (*GIsiResponseFunc)(GIsiClient *client,
 		const void *restrict data, size_t len,
 		uint16_t object, void *opaque);
@@ -51,8 +53,15 @@ typedef void (*GIsiDebugFunc) (const void *restrict data, size_t len,
 
 GIsiClient *g_isi_client_create(GIsiModem *modem, uint8_t resource);
 
+GIsiRequest *g_isi_verify(GIsiClient *client, GIsiVerifyFunc func,
+				void *opaque);
+
 uint8_t g_isi_client_resource(GIsiClient *client);
 
+void g_isi_version_set(GIsiClient *client, int major, int minor);
+int g_isi_version_major(GIsiClient *client);
+int g_isi_version_minor(GIsiClient *client);
+
 void g_isi_client_set_debug(GIsiClient *client, GIsiDebugFunc func,
 				void *opaque);
 
diff --git a/gisi/verify.c b/gisi/verify.c
new file mode 100644
index 00000000..f94aeea9
--- /dev/null
+++ b/gisi/verify.c
@@ -0,0 +1,106 @@
+/*
+ * This file is part of oFono - Open Source Telephony
+ *
+ * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+ *
+ * Contact: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <glib.h>
+
+#include "client.h"
+
+#define VERSION_TIMEOUT				5
+
+#define COMMON_MESSAGE				0xF0
+#define COMM_ISI_VERSION_GET_REQ		0x12
+#define COMM_ISI_VERSION_GET_RESP		0x13
+#define COMM_ISA_ENTITY_NOT_REACHABLE_RESP	0x14
+
+struct verify_data {
+	void *func;
+	void *data;
+};
+
+static bool verify_cb(GIsiClient *client, const void *restrict data,
+			size_t len, uint16_t object, void *opaque)
+{
+	const uint8_t *msg = data;
+	struct verify_data *vd = opaque;
+	GIsiVerifyFunc func = vd->func;
+
+	bool alive = false;
+
+	if(!msg)
+		goto out;
+
+	if (len < 4 || msg[0] != COMMON_MESSAGE)
+		goto out;
+
+	if (msg[1] == COMM_ISI_VERSION_GET_RESP) {
+		g_isi_version_set(client, msg[2], msg[3]);
+		alive = true;
+		goto out;
+	}
+
+	if (msg[1] != COMM_ISA_ENTITY_NOT_REACHABLE_RESP)
+		alive = true;
+
+out:
+	if (func)
+		func(client, alive, vd->data);
+	g_free(vd);
+	return true;
+}
+
+/**
+ * Verifies reachability of @a client with its resource. As a side
+ * effect of this liveliness check, the ISI version of the client
+ * resource will be made available via g_isi_client_version().
+ * @param client client to verify
+ * @param func callback to process outcome
+ * @param opaque user data
+ * @return NULL on error (see errno), GIsiRequest pointer on success.
+ */
+GIsiRequest *g_isi_verify(GIsiClient *client, GIsiVerifyFunc func,
+				void *opaque)
+{
+	struct verify_data *data = g_try_new0(struct verify_data, 1);
+	GIsiRequest *req = NULL;
+	uint8_t msg[] = {
+		COMMON_MESSAGE,
+		COMM_ISI_VERSION_GET_REQ,
+		0x00  /* Filler */
+	};
+
+	data->func = func;
+	data->data = opaque;
+
+	req = g_isi_request_make(client, msg, sizeof(msg), VERSION_TIMEOUT,
+					verify_cb, data);
+	if (!req)
+		g_free(data);
+
+	return req;
+}