diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index b6d040433..a364c17d7 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -49,6 +49,7 @@ enum {
 	NAT_CON_TYPE_LU,
 	NAT_CON_TYPE_CM_SERV_REQ,
 	NAT_CON_TYPE_PAG_RESP,
+	NAT_CON_TYPE_SSA,
 	NAT_CON_TYPE_LOCAL_REJECT,
 	NAT_CON_TYPE_OTHER,
 };
@@ -102,6 +103,7 @@ enum bsc_cfg_ctr {
 	BCFG_CTR_CON_TYPE_LU,
 	BCFG_CTR_CON_CMSERV_RQ,
 	BCFG_CTR_CON_PAG_RESP,
+	BCFG_CTR_CON_SSA,
 	BCFG_CTR_CON_OTHER,
 };
 
diff --git a/openbsc/src/nat/bsc_nat_utils.c b/openbsc/src/nat/bsc_nat_utils.c
index dc18cffec..f88e76697 100644
--- a/openbsc/src/nat/bsc_nat_utils.c
+++ b/openbsc/src/nat/bsc_nat_utils.c
@@ -54,6 +54,7 @@ static const struct rate_ctr_desc bsc_cfg_ctr_description[] = {
 	[BCFG_CTR_CON_TYPE_LU]   = { "conn.lu",        "Conn Location Update     "},
 	[BCFG_CTR_CON_CMSERV_RQ] = { "conn.rq",        "Conn CM Service Req      "},
 	[BCFG_CTR_CON_PAG_RESP]  = { "conn.pag",       "Conn Paging Response     "},
+	[BCFG_CTR_CON_SSA]       = { "conn.ssa",       "Conn USSD                "},
 	[BCFG_CTR_CON_OTHER]     = { "conn.other",     "Conn Other               "},
 };
 
@@ -391,7 +392,7 @@ static int _cr_check_loc_upd(struct bsc_connection *bsc,
 
 static int _cr_check_cm_serv_req(struct bsc_connection *bsc,
 				 uint8_t *data, unsigned int length,
-				 char **imsi)
+				 int *con_type, char **imsi)
 {
 	static const uint32_t classmark_offset =
 				offsetof(struct gsm48_service_request, classmark);
@@ -410,6 +411,8 @@ static int _cr_check_cm_serv_req(struct bsc_connection *bsc,
 	}
 
 	req = (struct gsm48_service_request *) data;
+	if (req->cm_service_type == 0x8)
+		*con_type = NAT_CON_TYPE_SSA;
 	rc = gsm48_extract_mi((uint8_t *) &req->classmark,
 			      length - classmark_offset, mi_string, &mi_type);
 	if (rc < 0) {
@@ -537,7 +540,9 @@ int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg,
 	} else if (hdr48->proto_discr == GSM48_PDISC_MM &&
 		  msg_type == GSM48_MT_MM_CM_SERV_REQ) {
 		*con_type = NAT_CON_TYPE_CM_SERV_REQ;
-		return _cr_check_cm_serv_req(bsc, &hdr48->data[0], hdr48_len - sizeof(*hdr48), imsi);
+		return _cr_check_cm_serv_req(bsc, &hdr48->data[0],
+					     hdr48_len - sizeof(*hdr48),
+					     con_type, imsi);
 	} else if (hdr48->proto_discr == GSM48_PDISC_RR &&
 		   msg_type == GSM48_MT_RR_PAG_RESP) {
 		*con_type = NAT_CON_TYPE_PAG_RESP;
@@ -614,6 +619,7 @@ static const char *con_types [] = {
 	[NAT_CON_TYPE_LU] = "Location Update",
 	[NAT_CON_TYPE_CM_SERV_REQ] = "CM Serv Req",
 	[NAT_CON_TYPE_PAG_RESP] = "Paging Response",
+	[NAT_CON_TYPE_SSA] = "Supplementar Service Activation",
 	[NAT_CON_TYPE_LOCAL_REJECT] = "Local Reject",
 	[NAT_CON_TYPE_OTHER] = "Other",
 };
@@ -693,6 +699,7 @@ static const int con_to_ctr[] = {
 	[NAT_CON_TYPE_LU]		= BCFG_CTR_CON_TYPE_LU,
 	[NAT_CON_TYPE_CM_SERV_REQ]	= BCFG_CTR_CON_CMSERV_RQ,
 	[NAT_CON_TYPE_PAG_RESP]		= BCFG_CTR_CON_PAG_RESP,
+	[NAT_CON_TYPE_SSA]		= BCFG_CTR_CON_SSA,
 	[NAT_CON_TYPE_LOCAL_REJECT]	= -1,
 	[NAT_CON_TYPE_OTHER]		= BCFG_CTR_CON_OTHER,
 };