diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index 6e93e14..2026d1a 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -614,6 +614,8 @@
 				  uint16_t nsvci, uint16_t ns_bvci)
 {
 	struct gbproxy_peer *peer;
+	struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
+	uint8_t pdu_type = bgph->pdu_type;
 	int rc;
 
 	peer = gbproxy_peer_by_bvci(cfg, ns_bvci);
@@ -625,6 +627,19 @@
 	if (!rc)
 		return 0;
 
+	switch (pdu_type) {
+	case BSSGP_PDUT_FLOW_CONTROL_BVC:
+		if (!cfg->route_to_sgsn2)
+			break;
+
+		/* Send a copy to the secondary SGSN */
+		gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn2_nsei);
+		break;
+	default:
+		break;
+	}
+
+
 	return gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn_nsei);
 }
 
@@ -634,6 +649,8 @@
 				   uint16_t nsvci, uint16_t ns_bvci)
 {
 	struct gbproxy_peer *peer;
+	struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
+	uint8_t pdu_type = bgph->pdu_type;
 
 	peer = gbproxy_peer_by_bvci(cfg, ns_bvci);
 
@@ -657,6 +674,19 @@
 		return bssgp_tx_status(BSSGP_CAUSE_BVCI_BLOCKED, NULL, msg);
 	}
 
+	switch (pdu_type) {
+	case BSSGP_PDUT_FLOW_CONTROL_BVC_ACK:
+	case BSSGP_PDUT_BVC_BLOCK_ACK:
+	case BSSGP_PDUT_BVC_UNBLOCK_ACK:
+		if (cfg->route_to_sgsn2 && nsei == cfg->nsip_sgsn2_nsei)
+			/* Hide ACKs from the secondary SGSN, the primary SGSN
+			 * is responsible to send them. */
+			return 0;
+		break;
+	default:
+		break;
+	}
+
 	/* Optionally patch the message */
 	gbprox_process_bssgp_dl(cfg, msg, peer);
 
@@ -674,6 +704,7 @@
 	int data_len = msgb_bssgp_len(msg) - sizeof(*bgph);
 	struct gbproxy_peer *from_peer = NULL;
 	struct gprs_ra_id raid;
+	int copy_to_sgsn2 = 0;
 	int rc;
 
 	if (ns_bvci != 0 && ns_bvci != 1) {
@@ -758,6 +789,8 @@
 				     bvci, raid.mcc, raid.mnc, raid.lac,
 				     raid.rac);
 			}
+			if (cfg->route_to_sgsn2)
+				copy_to_sgsn2 = 1;
 		}
 		break;
 	}
@@ -767,6 +800,10 @@
 	rc = gbprox_process_bssgp_ul(cfg, msg, from_peer);
 	if (!rc)
 		return 0;
+
+	if (copy_to_sgsn2)
+		gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn2_nsei);
+
 	return gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn_nsei);
 err_no_peer:
 	LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(BSS) cannot find peer based on NSEI\n",
@@ -900,8 +937,11 @@
 	case BSSGP_PDUT_BVC_RESET:
 		rc = rx_reset_from_sgsn(cfg, msg, orig_msg, &tp, nsei, ns_bvci);
 		break;
-	case BSSGP_PDUT_FLUSH_LL:
 	case BSSGP_PDUT_BVC_RESET_ACK:
+		if (cfg->route_to_sgsn2 && nsei == cfg->nsip_sgsn2_nsei)
+			break;
+		/* fall through */
+	case BSSGP_PDUT_FLUSH_LL:
 		/* simple case: BVCI IE is mandatory */
 		if (!TLVP_PRESENT(&tp, BSSGP_IE_BVCI))
 			goto err_mand_ie;