diff --git a/doc/manuals/chapters/configuration.adoc b/doc/manuals/chapters/configuration.adoc
index d778929..ca3963d 100644
--- a/doc/manuals/chapters/configuration.adoc
+++ b/doc/manuals/chapters/configuration.adoc
@@ -422,3 +422,71 @@
 accomplished and there's no penalty. However, if only EGPRS downlink data is sent
 over that time frame, then the scheduler will force sending a RLCMAC Dummy
 Block.
+
+[[gsmtap]]
+=== Configuring GSMTAP tracing
+
+In addition to being able to obtain pcap protocol traces of the NS/BSSGP
+communication and the text-based logging from the OsmoPCU software, there is
+also the capability of tracing all communication on the radio interface related
+to PS. To do so, OsmoPCU can encapsulate MAC blocks (23-155 byte messages at the
+L2-L1 interface depending on coding scheme) into _GSMTAP_ and send them via
+UDP/IP. At that point, they can be captured with utilities like *tcpdump* or
+*tshark* for further analysis by the *wireshark* protocol analyzer.
+
+In order to activate this feature, you first need to make sure to specify
+the remote address of _GSMTAP_ host in the configuration file.  In most
+cases, using 127.0.0.1 for passing the messages over the loopback (`lo`)
+device will be sufficient:
+
+.Example: Enabling GSMTAP Um-frame logging to localhost
+----
+pcu
+ gsmtap-remote-host 127.0.0.1 <1>
+----
+<1> Destination address for _GSMTAP_ Um-frames
+
+NOTE: Changing this parameter at run-time will not affect the existing
+_GSMTAP_ connection, full program restart is required.
+
+NOTE: Command line parameters `-i` and `--gsmtap-ip` have been deprecated.
+
+OsmoPCU can selectively trace such messages based on different categories, for
+both Ul and Dl. For a complete list of cateogry values, please refer to the
+_OsmoPCU VTY reference manual_ <<vty-ref-osmopcu>>.
+
+For example, to enable GSMTAP tracing for all DL EGPRS rlcmac data blocks, you
+can use the `gsmtap-category dl-data-egprs` command at the `pcu` node of the
+OsmoPCU VTY.
+
+.Example: Enabling  GSMTAP for for all DL EGPRS rlcmac data blocks
+----
+OsmoPCU> enable
+OsmoPCU# configure terminal
+OsmoPCU(config)# pcu
+OsmoPCU(pcu)# gsmtap-category dl-data-egprs
+OsmoPCU(trx)# write <1>
+----
+<1> the `write` command will make the configuration persistent in the
+configuration file.  This is not required if you wish to enable GSMTAP
+only in the current session of OsmoPCU.
+
+De-activation can be performed similarly by using the `no gsmtap-category
+dl-data-egprs` command at the `pcu` node of the OsmoPCU VTY.
+
+It may be useful to enable all categories with a few exceptions, or vice versa
+disable everything using one command.  For this purpose, the VTY provides
+`gsmtap-category enable-all` and `gsmtap-category disable-all` commands.
+
+.Example: Enabling all categoriess except _dl-dummy_
+----
+pcu
+ gsmtap-category enable-all <1>
+ no gsmtap-category dl-dummy <2>
+----
+<1> Enable all available SAPIs
+<2> Exclude DL RLCMAC blocks
+
+From the moment they are enabled via VTY, GSMTAP messages will be
+generated and sent in UDP encapsulation to the IANA-registered UDP port
+for GSMTAP (4729) of the specified remote address.
diff --git a/doc/manuals/chapters/running.adoc b/doc/manuals/chapters/running.adoc
index 78f79b6..c763974 100644
--- a/doc/manuals/chapters/running.adoc
+++ b/doc/manuals/chapters/running.adoc
@@ -25,5 +25,3 @@
 	Use the given MCC instead of that provided by BTS via PCU socket
 *-n, --mnc 'MNC'*::
 	Use the given MNC instead of that provided by BTS via PCU socket
-*-i, --gsmtap-ip 'A.B.C.D'*::
-        Send Um interface trace via GSMTAP to specified IP address
diff --git a/src/gprs_pcu.h b/src/gprs_pcu.h
index fdcf5f7..ed00221 100644
--- a/src/gprs_pcu.h
+++ b/src/gprs_pcu.h
@@ -117,6 +117,7 @@
 
 	struct gsmtap_inst *gsmtap;
 	uint32_t gsmtap_categ_mask;
+	char *gsmtap_remote_host;
 
 	struct llist_head bts_list; /* list of gprs_rlcmac_bts */
 
diff --git a/src/pcu_main.cpp b/src/pcu_main.cpp
index 7992853..fe391b9 100644
--- a/src/pcu_main.cpp
+++ b/src/pcu_main.cpp
@@ -64,7 +64,7 @@
 static int quit = 0;
 static int rt_prio = -1;
 static bool daemonize = false;
-static const char *gsmtap_addr = "localhost"; // FIXME: use gengetopt's default value instead
+static const char *gsmtap_addr;
 
 static void print_help()
 {
@@ -75,7 +75,6 @@
 		"  -n	--mnc MNC		Use given MNC instead of value provided by BTS\n"
 		"  -V	--version		Print version\n"
 		"  -D	--daemonize		Fork the process into a background daemon\n"
-		"  -i	--gsmtap-ip		The destination IP used for GSMTAP\n"
 		"\nVTY reference generation:\n"
 		"    	--vty-ref-mode MODE	VTY reference generation mode (e.g. 'expert').\n"
 		"    	--vty-ref-xml		Generate the VTY reference XML output and exit.\n"
@@ -161,6 +160,8 @@
 			break;
 		case 'i':
 			gsmtap_addr = optarg;
+			fprintf(stderr, "Command line argument '-i' is deprecated, use VTY "
+				"parameter 'gsmtap-remote-host %s' instead.\n", gsmtap_addr);
 			break;
 		case 'r':
 			rt_prio = atoi(optarg);
@@ -258,13 +259,6 @@
 		exit(0);
 	}
 
-	pcu->gsmtap = gsmtap_source_init(gsmtap_addr, GSMTAP_UDP_PORT, 1);
-
-	if (pcu->gsmtap)
-		gsmtap_source_add_sink(pcu->gsmtap);
-	else
-		fprintf(stderr, "Failed to initialize GSMTAP for %s\n", gsmtap_addr);
-
 	pcu->nsi = gprs_ns2_instantiate(tall_pcu_ctx, gprs_ns_prim_cb, NULL);
 	if (!pcu->nsi) {
 		LOGP(DBSSGP, LOGL_ERROR, "Failed to create NS instance\n");
@@ -283,6 +277,31 @@
 		fprintf(stderr, "No config file: '%s' Using default config.\n",
 			config_file);
 
+	/* Accept a GSMTAP host from VTY config, but a commandline option overrides that. */
+	if (gsmtap_addr) {
+		if (pcu->gsmtap_remote_host != NULL) {
+			LOGP(DLGLOBAL, LOGL_NOTICE,
+			     "Command line argument '-i %s' overrides "
+			     "'gsmtap-remote-host %s' from the config file\n",
+			     gsmtap_addr, pcu->gsmtap_remote_host);
+			talloc_free(pcu->gsmtap_remote_host);
+		}
+		pcu->gsmtap_remote_host = talloc_strdup(pcu, gsmtap_addr);
+	}
+
+	if (pcu->gsmtap_remote_host) {
+		LOGP(DLGLOBAL, LOGL_NOTICE,
+		     "Setting up GSMTAP Um forwarding to '%s:%u'\n",
+		     pcu->gsmtap_remote_host, GSMTAP_UDP_PORT);
+		pcu->gsmtap = gsmtap_source_init(pcu->gsmtap_remote_host,
+							GSMTAP_UDP_PORT, 1);
+		if (pcu->gsmtap == NULL) {
+			fprintf(stderr, "Failed during gsmtap_source_init()\n");
+			exit(1);
+		}
+		gsmtap_source_add_sink(pcu->gsmtap);
+	}
+
 	rc = telnet_init_dynif(tall_pcu_ctx, NULL, vty_get_bind_addr(),
 			       OSMO_VTY_PORT_PCU);
 	if (rc < 0) {
diff --git a/src/pcu_vty.c b/src/pcu_vty.c
index c85e324..6b33e29 100644
--- a/src/pcu_vty.c
+++ b/src/pcu_vty.c
@@ -70,6 +70,49 @@
 	{ 0, NULL }
 };
 
+DEFUN(cfg_pcu_gsmtap_remote_host,
+      cfg_pcu_gsmtap_remote_host_cmd,
+      "gsmtap-remote-host [HOSTNAME]",
+      "Enable GSMTAP Um logging (see also 'gsmtap-category')\n"
+      "Remote IP address or hostname ('localhost' if omitted)\n")
+{
+	osmo_talloc_replace_string(the_pcu, &the_pcu->gsmtap_remote_host,
+				   argc > 0 ? argv[0] : "localhost");
+
+	if (vty->type != VTY_FILE)
+		vty_out(vty, "%% This command requires restart%s", VTY_NEWLINE);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_pcu_no_gsmtap_remote_host,
+      cfg_pcu_no_gsmtap_remote_host_cmd,
+      "no gsmtap-remote-host",
+      NO_STR "Disable GSMTAP Um logging\n")
+{
+	if (the_pcu->gsmtap_remote_host)
+		TALLOC_FREE(the_pcu->gsmtap_remote_host);
+
+	if (vty->type != VTY_FILE)
+		vty_out(vty, "%% This command requires restart%s", VTY_NEWLINE);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_pcu_gsmtap_sapi_all, pcucfg_pcu_gsmtap_categ_all_cmd,
+	"gsmtap-category (enable-all|disable-all)",
+	"Enable/disable sending of UL/DL messages over GSMTAP\n"
+	"Enable all kinds of messages (all categories)\n"
+	"Disable all kinds of messages (all categories)\n")
+{
+
+	if (strcmp(argv[0], "enable-all") == 0)
+		the_pcu->gsmtap_categ_mask = UINT32_MAX;
+	else
+		the_pcu->gsmtap_categ_mask = 0x00;
+
+	return CMD_SUCCESS;
+}
 
 DEFUN(cfg_pcu_gsmtap_categ, cfg_pcu_gsmtap_categ_cmd, "HIDDEN", "HIDDEN")
 {
@@ -238,11 +281,14 @@
 	if (strcmp(the_pcu->pcu_sock_path, PCU_SOCK_DEFAULT))
 		vty_out(vty, " pcu-socket %s%s", the_pcu->pcu_sock_path, VTY_NEWLINE);
 
+	if (the_pcu->gsmtap_remote_host)
+		vty_out(vty, " gsmtap-remote-host %s%s", the_pcu->gsmtap_remote_host, VTY_NEWLINE);
 	for (i = 0; i < 32; i++) {
-		uint32_t cs = ((uint32_t)1 << i);
-		if (the_pcu->gsmtap_categ_mask & cs) {
-			vty_out(vty, " gsmtap-category %s%s",
-				get_value_string(pcu_gsmtap_categ_names, i), VTY_NEWLINE);
+		if (the_pcu->gsmtap_categ_mask & ((uint32_t)1 << i)) {
+			const char *category_buf;
+			if (!(category_buf = get_value_string_or_null(pcu_gsmtap_categ_names, i)))
+				continue;
+			vty_out(vty, " gsmtap-category %s%s", category_buf, VTY_NEWLINE);
 		}
 	}
 
@@ -1294,6 +1340,9 @@
 	install_element(PCU_NODE, &cfg_pcu_no_dl_tbf_preemptive_retransmission_cmd);
 	install_element(PCU_NODE, &cfg_pcu_ms_idle_time_cmd);
 	install_element(PCU_NODE, &cfg_pcu_no_ms_idle_time_cmd);
+	install_element(PCU_NODE, &cfg_pcu_gsmtap_remote_host_cmd);
+	install_element(PCU_NODE, &cfg_pcu_no_gsmtap_remote_host_cmd);
+	install_element(PCU_NODE, &pcucfg_pcu_gsmtap_categ_all_cmd);
 	install_element(PCU_NODE, &cfg_pcu_gsmtap_categ_cmd);
 	install_element(PCU_NODE, &cfg_pcu_no_gsmtap_categ_cmd);
 	install_element(PCU_NODE, &cfg_pcu_sock_cmd);