diff --git a/openbsc/include/openbsc/signal.h b/openbsc/include/openbsc/signal.h
index 39319f1..8f27b38 100644
--- a/openbsc/include/openbsc/signal.h
+++ b/openbsc/include/openbsc/signal.h
@@ -1,5 +1,5 @@
 /* Generic signalling/notification infrastructure */
-/* (C) 2009-2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+/* (C) 2009-2010, 2015 by Holger Hans Peter Freyther <zecke@selfish.org>
  * (C) 2009 by Harald Welte <laforge@gnumonks.org>
  * (C) 2010 by On-Waves
  * All Rights Reserved
@@ -46,6 +46,7 @@
 	SS_MSC,
 	SS_HO,
 	SS_CCCH,
+	SS_SGSN,
 };
 
 /* SS_PAGING signals */
@@ -241,4 +242,22 @@
 	uint16_t rach_access_count;
 };
 
+/* GPRS SGSN signals SS_SGSN */
+enum signal_sgsn {
+	S_SGSN_ATTACH,
+	S_SGSN_DETACH,
+	S_SGSN_UPDATE,
+	S_SGSN_PDP_ACT,
+	S_SGSN_PDP_DEACT,
+	S_SGSN_PDP_TERMINATE,
+	S_SGSN_PDP_FREE,
+	S_SGSN_MM_FREE,
+};
+
+struct sgsn_mm_ctx;
+struct sgsn_signal_data {
+	struct sgsn_mm_ctx *mm;
+	struct sgsn_pdp_ctx *pdp;	/* non-NULL for PDP_ACT, PDP_DEACT, PDP_FREE */
+};
+
 #endif
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 2a856a6..8ada3d4 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -52,6 +52,7 @@
 #include <openbsc/gprs_gmm.h>
 #include <openbsc/gprs_utils.h>
 #include <openbsc/sgsn.h>
+#include <openbsc/signal.h>
 
 #include <pdp.h>
 
@@ -580,6 +581,10 @@
 /* Check if we can already authorize a subscriber */
 static int gsm48_gmm_authorize(struct sgsn_mm_ctx *ctx)
 {
+#ifndef PTMSI_ALLOC
+	struct sgsn_signal_data sig_data;
+#endif
+
 	/* Request IMSI and IMEI from the MS if they are unknown */
 	if (!strlen(ctx->imei)) {
 		ctx->t3370_id_type = GSM_MI_TYPE_IMEI;
@@ -643,6 +648,9 @@
 		mmctx_timer_start(ctx, 3350, GSM0408_T3350_SECS);
 		ctx->t3350_mode = GMM_T3350_MODE_ATT;
 #else
+		memset(&sig_data, 0, sizeof(sig_data));
+		sig_data.mm = mmctx;
+		osmo_signal_dispatch(SS_SGSN, S_SGSN_ATTACH, &sig_data);
 		ctx->mm_state = GMM_REGISTERED_NORMAL;
 #endif
 
@@ -976,8 +984,13 @@
 			rc = gsm48_tx_gmm_det_ack_oldmsg(msg, 0);
 	}
 
-	if (ctx)
+	if (ctx) {
+		struct sgsn_signal_data sig_data;
+		memset(&sig_data, 0, sizeof(sig_data));
+		sig_data.mm = ctx;
+		osmo_signal_dispatch(SS_SGSN, S_SGSN_DETACH, &sig_data);
 		mm_ctx_cleanup_free(ctx, "GPRS DETACH REQUEST");
+	}
 
 	return rc;
 }
@@ -1083,6 +1096,9 @@
 static int gsm48_rx_gmm_ra_upd_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
 				   struct gprs_llc_llme *llme)
 {
+#ifndef PTMSI_ALLOC
+	struct sgsn_signal_data sig_data;
+#endif
 	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
 	uint8_t *cur = gh->data;
 	uint8_t ms_ra_acc_cap_len;
@@ -1168,6 +1184,10 @@
 #else
 	/* Make sure we are NORMAL (i.e. not SUSPENDED anymore) */
 	mmctx->mm_state = GMM_REGISTERED_NORMAL;
+
+	memset(&sig_data, 0, sizeof(sig_data));
+	sig_data.mm = mmctx;
+	osmo_signal_dispatch(SS_SGSN, S_SGSN_UPDATE, &sig_data);
 #endif
 	/* Even if there is no P-TMSI allocated, the MS will switch from
 	 * foreign TLLI to local TLLI */
@@ -1217,6 +1237,7 @@
 static int gsm0408_rcv_gmm(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
 			   struct gprs_llc_llme *llme)
 {
+	struct sgsn_signal_data sig_data;
 	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
 	int rc;
 
@@ -1298,6 +1319,10 @@
 				  GPRS_ALGO_GEA0, NULL);
 		mmctx->mm_state = GMM_REGISTERED_NORMAL;
 		rc = 0;
+
+		memset(&sig_data, 0, sizeof(sig_data));
+		sig_data.mm = mmctx;
+		osmo_signal_dispatch(SS_SGSN, S_SGSN_ATTACH, &sig_data);
 		break;
 	case GSM48_MT_GMM_RA_UPD_COMPL:
 		/* only in case SGSN offered new P-TMSI */
@@ -1312,6 +1337,10 @@
 				  GPRS_ALGO_GEA0, NULL);
 		mmctx->mm_state = GMM_REGISTERED_NORMAL;
 		rc = 0;
+
+		memset(&sig_data, 0, sizeof(sig_data));
+		sig_data.mm = mmctx;
+		osmo_signal_dispatch(SS_SGSN, S_SGSN_UPDATE, &sig_data);
 		break;
 	case GSM48_MT_GMM_PTMSI_REALL_COMPL:
 		LOGMMCTXP(LOGL_INFO, mmctx, "-> PTMSI REALLLICATION COMPLETE\n");
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 2f5d39e..5fe4e61 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -36,6 +36,7 @@
 #include <openbsc/gsm_04_08_gprs.h>
 #include <openbsc/gprs_gmm.h>
 #include <openbsc/gprs_utils.h>
+#include <openbsc/signal.h>
 #include "openbsc/gprs_llc.h"
 
 #include <time.h>
@@ -204,6 +205,7 @@
 	struct gprs_llc_llme *llme = mm->llme;
 	uint32_t tlli = mm->tlli;
 	struct sgsn_pdp_ctx *pdp, *pdp2;
+	struct sgsn_signal_data sig_data;
 
 	/* delete all existing PDP contexts for this MS */
 	llist_for_each_entry_safe(pdp, pdp2, &mm->pdp_list, list) {
@@ -217,6 +219,11 @@
 		osmo_timer_del(&mm->timer);
 	}
 
+	memset(&sig_data, 0, sizeof(sig_data));
+	sig_data.mm = mm;
+	osmo_signal_dispatch(SS_SGSN, S_SGSN_MM_FREE, &sig_data);
+
+
 	/* Detach from subscriber which is possibly freed then */
 	if (mm->subscr) {
 		struct gsm_subscriber *subscr = subscr_get(mm->subscr);
@@ -289,6 +296,8 @@
  */
 void sgsn_pdp_ctx_terminate(struct sgsn_pdp_ctx *pdp)
 {
+	struct sgsn_signal_data sig_data;
+
 	OSMO_ASSERT(pdp->mm != NULL);
 
 	/* There might still be pending callbacks in libgtp. So the parts of
@@ -299,6 +308,10 @@
 	/* Force the deactivation of the SNDCP layer */
 	sndcp_sm_deactivate_ind(&pdp->mm->llme->lle[pdp->sapi], pdp->nsapi);
 
+	memset(&sig_data, 0, sizeof(sig_data));
+	sig_data.pdp = pdp;
+	osmo_signal_dispatch(SS_SGSN, S_SGSN_PDP_TERMINATE, &sig_data);
+
 	/* Detach from MM context */
 	llist_del(&pdp->list);
 	pdp->mm = NULL;
@@ -313,6 +326,12 @@
  */
 void sgsn_pdp_ctx_free(struct sgsn_pdp_ctx *pdp)
 {
+	struct sgsn_signal_data sig_data;
+
+	memset(&sig_data, 0, sizeof(sig_data));
+	sig_data.pdp = pdp;
+	osmo_signal_dispatch(SS_SGSN, S_SGSN_PDP_FREE, &sig_data);
+
 	rate_ctr_group_free(pdp->ctrg);
 	if (pdp->mm)
 		llist_del(&pdp->list);
diff --git a/openbsc/src/gprs/sgsn_libgtp.c b/openbsc/src/gprs/sgsn_libgtp.c
index eee3ef2..af5c93d 100644
--- a/openbsc/src/gprs/sgsn_libgtp.c
+++ b/openbsc/src/gprs/sgsn_libgtp.c
@@ -287,6 +287,7 @@
 /* The GGSN has confirmed the creation of a PDP Context */
 static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 {
+	struct sgsn_signal_data sig_data;
 	struct sgsn_pdp_ctx *pctx = cbp;
 	uint8_t reject_cause;
 
@@ -322,6 +323,11 @@
 	/* Activate the SNDCP layer */
 	sndcp_sm_activate_ind(&pctx->mm->llme->lle[pctx->sapi], pctx->nsapi);
 
+	/* Inform others about it */
+	memset(&sig_data, 0, sizeof(sig_data));
+	sig_data.pdp = pctx;
+	osmo_signal_dispatch(SS_SGSN, S_SGSN_PDP_ACT, &sig_data);
+
 	/* Send PDP CTX ACT to MS */
 	return gsm48_tx_gsm_act_pdp_acc(pctx);
 
@@ -349,12 +355,17 @@
 /* Confirmation of a PDP Context Delete */
 static int delete_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 {
+	struct sgsn_signal_data sig_data;
 	struct sgsn_pdp_ctx *pctx = cbp;
 	int rc = 0;
 
 	LOGPDPCTXP(LOGL_INFO, pctx, "Received DELETE PDP CTX CONF, cause=%d(%s)\n",
 		cause, get_value_string(gtp_cause_strs, cause));
 
+	memset(&sig_data, 0, sizeof(sig_data));
+	sig_data.pdp = pctx;
+	osmo_signal_dispatch(SS_SGSN, S_SGSN_PDP_DEACT, &sig_data);
+
 	if (pctx->mm) {
 		/* Deactivate the SNDCP layer */
 		sndcp_sm_deactivate_ind(&pctx->mm->llme->lle[pctx->sapi], pctx->nsapi);