diff --git a/include/osmocom/gprs/gprs_ns2.h b/include/osmocom/gprs/gprs_ns2.h
index 5cebf27..dc27c96 100644
--- a/include/osmocom/gprs/gprs_ns2.h
+++ b/include/osmocom/gprs/gprs_ns2.h
@@ -107,23 +107,23 @@
 
 /* IP VL driver */
 int gprs_ns2_ip_bind(struct gprs_ns2_inst *nsi,
-		     struct osmo_sockaddr *local,
+		     const struct osmo_sockaddr *local,
 		     int dscp,
 		     struct gprs_ns2_vc_bind **result);
 void gprs_ns2_bind_set_mode(struct gprs_ns2_vc_bind *bind, enum gprs_ns2_vc_mode mode);
 
 /* create a VC connection */
 struct gprs_ns2_vc *gprs_ns2_ip_connect(struct gprs_ns2_vc_bind *bind,
-					struct osmo_sockaddr *remote,
+					const struct osmo_sockaddr *remote,
 					struct gprs_ns2_nse *nse,
 					uint16_t nsvci);
 
 struct gprs_ns2_vc *gprs_ns2_ip_connect2(struct gprs_ns2_vc_bind *bind,
-					 struct osmo_sockaddr *remote,
+					 const struct osmo_sockaddr *remote,
 					 uint16_t nsei,
 					 uint16_t nsvci);
 struct gprs_ns2_vc *gprs_ns2_ip_connect_inactive(struct gprs_ns2_vc_bind *bind,
-					struct osmo_sockaddr *remote,
+					const struct osmo_sockaddr *remote,
 					struct gprs_ns2_nse *nse,
 					uint16_t nsvci);
 
@@ -131,7 +131,7 @@
 
 /* create a VC SNS connection */
 int gprs_ns2_ip_connect_sns(struct gprs_ns2_vc_bind *bind,
-			    struct osmo_sockaddr *remote,
+			    const struct osmo_sockaddr *remote,
 			    uint16_t nsei);
 
 struct osmo_sockaddr *gprs_ns2_ip_vc_sockaddr(struct gprs_ns2_vc *nsvc);
@@ -140,17 +140,17 @@
 int gprs_ns2_ip_bind_set_dscp(struct gprs_ns2_vc_bind *bind, int dscp);
 struct gprs_ns2_vc *gprs_ns2_nsvc_by_sockaddr_bind(
 		struct gprs_ns2_vc_bind *bind,
-		struct osmo_sockaddr *saddr);
+		const struct osmo_sockaddr *saddr);
 
 int gprs_ns2_frgre_bind(struct gprs_ns2_inst *nsi,
-			struct osmo_sockaddr *local,
+			const struct osmo_sockaddr *local,
 			int dscp,
 			struct gprs_ns2_vc_bind **result);
 int gprs_ns2_is_frgre_bind(struct gprs_ns2_vc_bind *bind);
 
 struct gprs_ns2_vc *gprs_ns2_nsvc_by_sockaddr_nse(
 		struct gprs_ns2_nse *nse,
-		struct osmo_sockaddr *sockaddr);
+		const struct osmo_sockaddr *sockaddr);
 void gprs_ns2_start_alive_all_nsvcs(struct gprs_ns2_nse *nse);
 const char *gprs_ns2_cause_str(int cause);
 const char *gprs_ns2_ll_str(struct gprs_ns2_vc *nsvc);
@@ -158,7 +158,8 @@
 char *gprs_ns2_ll_str_c(const void *ctx, struct gprs_ns2_vc *nsvc);
 
 /* vty */
-int gprs_ns2_vty_init(struct gprs_ns2_inst *nsi, struct osmo_sockaddr_str *default_bind);
+int gprs_ns2_vty_init(struct gprs_ns2_inst *nsi,
+		      const struct osmo_sockaddr_str *default_bind);
 int gprs_ns2_vty_create();
 void gprs_ns2_vty_force_vc_mode(bool force, enum gprs_ns2_vc_mode mode, const char *reason);
 
diff --git a/src/gb/gprs_ns2.c b/src/gb/gprs_ns2.c
index b82fd0d..86813f3 100644
--- a/src/gb/gprs_ns2.c
+++ b/src/gb/gprs_ns2.c
@@ -729,7 +729,7 @@
  *  \param[in] nsvci is only required when bind->vc_mode == NS2_VC_MODE_BLOCKRESET
  *  \return pointer to newly-allocated, connected and inactive NS-VC; NULL on error */
 struct gprs_ns2_vc *gprs_ns2_ip_connect_inactive(struct gprs_ns2_vc_bind *bind,
-					struct osmo_sockaddr *remote,
+					const struct osmo_sockaddr *remote,
 					struct gprs_ns2_nse *nse,
 					uint16_t nsvci)
 {
@@ -754,7 +754,7 @@
  *  \param[in] nsvci is only required when bind->vc_mode == NS2_VC_MODE_BLOCKRESET
  *  \return pointer to newly-allocated, connected and activated NS-VC; NULL on error */
 struct gprs_ns2_vc *gprs_ns2_ip_connect(struct gprs_ns2_vc_bind *bind,
-					struct osmo_sockaddr *remote,
+					const struct osmo_sockaddr *remote,
 					struct gprs_ns2_nse *nse,
 					uint16_t nsvci)
 {
@@ -775,7 +775,7 @@
  *  \param[in] nsvci is only required when bind->vc_mode == NS2_VC_MODE_BLOCKRESET
  *  \return pointer to newly-allocated, connected and activated NS-VC; NULL on error */
 struct gprs_ns2_vc *gprs_ns2_ip_connect2(struct gprs_ns2_vc_bind *bind,
-					 struct osmo_sockaddr *remote,
+					 const struct osmo_sockaddr *remote,
 					 uint16_t nsei,
 					 uint16_t nsvci)
 {
@@ -796,7 +796,7 @@
  *  \param[in] nsei NSEI of the NS Entity in which the NS-VC is to be created
  *  \return 0 on success; negative on error */
 int gprs_ns2_ip_connect_sns(struct gprs_ns2_vc_bind *bind,
-			    struct osmo_sockaddr *remote,
+			    const struct osmo_sockaddr *remote,
 			    uint16_t nsei)
 {
 	struct gprs_ns2_nse *nse = gprs_ns2_nse_by_nsei(bind->nsi, nsei);
@@ -826,7 +826,7 @@
  *  \param[in] sockaddr socket address to search for
  *  \return NS-VC matching sockaddr; NULL if none found */
 struct gprs_ns2_vc *gprs_ns2_nsvc_by_sockaddr_nse(struct gprs_ns2_nse *nse,
-					      struct osmo_sockaddr *sockaddr)
+						  const struct osmo_sockaddr *sockaddr)
 {
 	struct gprs_ns2_vc *nsvc;
 	struct osmo_sockaddr *remote;
diff --git a/src/gb/gprs_ns2_frgre.c b/src/gb/gprs_ns2_frgre.c
index e0797b6..cd478d6 100644
--- a/src/gb/gprs_ns2_frgre.c
+++ b/src/gb/gprs_ns2_frgre.c
@@ -538,7 +538,7 @@
  *  \param[out] result pointer to created bind
  *  \return 0 on success; negative on error */
 int gprs_ns2_frgre_bind(struct gprs_ns2_inst *nsi,
-			struct osmo_sockaddr *local,
+			const struct osmo_sockaddr *local,
 			int dscp,
 			struct gprs_ns2_vc_bind **result)
 {
diff --git a/src/gb/gprs_ns2_internal.h b/src/gb/gprs_ns2_internal.h
index f5d9ed5..b480391 100644
--- a/src/gb/gprs_ns2_internal.h
+++ b/src/gb/gprs_ns2_internal.h
@@ -271,14 +271,14 @@
 /* driver */
 struct gprs_ns2_vc *gprs_ns2_ip_bind_connect(struct gprs_ns2_vc_bind *bind,
 					     struct gprs_ns2_nse *nse,
-					     struct osmo_sockaddr *remote);
+					     const struct osmo_sockaddr *remote);
 
 /* sns */
 int gprs_ns2_sns_rx(struct gprs_ns2_vc *nsvc, struct msgb *msg, struct tlv_parsed *tp);
 struct osmo_fsm_inst *ns2_sns_bss_fsm_alloc(struct gprs_ns2_nse *nse,
 					     const char *id);
 int ns2_sns_bss_fsm_start(struct gprs_ns2_nse *nse, struct gprs_ns2_vc *nsvc,
-			  struct osmo_sockaddr *remote);
+			  const struct osmo_sockaddr *remote);
 void ns2_sns_free_nsvc(struct gprs_ns2_vc *nsvc);
 
 /* vc */
diff --git a/src/gb/gprs_ns2_sns.c b/src/gb/gprs_ns2_sns.c
index 9ffb152..ec6f31f 100644
--- a/src/gb/gprs_ns2_sns.c
+++ b/src/gb/gprs_ns2_sns.c
@@ -1230,7 +1230,8 @@
  *  \param[in] nsvc Initial NS-VC
  *  \param[in] remote remote (SGSN) address
  *  \returns 0 on success; negative on error */
-int ns2_sns_bss_fsm_start(struct gprs_ns2_nse *nse, struct gprs_ns2_vc *nsvc, struct osmo_sockaddr *remote)
+int ns2_sns_bss_fsm_start(struct gprs_ns2_nse *nse, struct gprs_ns2_vc *nsvc,
+			  const struct osmo_sockaddr *remote)
 {
 	struct osmo_fsm_inst *fi = nse->bss_sns_fi;
 	struct ns2_sns_state *gss = (struct ns2_sns_state *) nse->bss_sns_fi->priv;
diff --git a/src/gb/gprs_ns2_udp.c b/src/gb/gprs_ns2_udp.c
index 207febf..815e516 100644
--- a/src/gb/gprs_ns2_udp.c
+++ b/src/gb/gprs_ns2_udp.c
@@ -110,7 +110,8 @@
  *  \param[in] bind in which to search
  *  \param[in] saddr remote peer socket adddress to search
  *  \returns NS-VC matching sockaddr; NULL if none found */
-struct gprs_ns2_vc *gprs_ns2_nsvc_by_sockaddr_bind(struct gprs_ns2_vc_bind *bind, struct osmo_sockaddr *saddr)
+struct gprs_ns2_vc *gprs_ns2_nsvc_by_sockaddr_bind(struct gprs_ns2_vc_bind *bind,
+						   const struct osmo_sockaddr *saddr)
 {
 	struct gprs_ns2_vc *nsvc;
 	struct priv_vc *vcpriv;
@@ -271,7 +272,7 @@
  *  \param[out] result if set, returns the bind object
  *  \return 0 on success; negative in case of error */
 int gprs_ns2_ip_bind(struct gprs_ns2_inst *nsi,
-		     struct osmo_sockaddr *local,
+		     const struct osmo_sockaddr *local,
 		     int dscp,
 		     struct gprs_ns2_vc_bind **result)
 {
@@ -339,7 +340,7 @@
  *  \return pointer to newly-allocated and connected NS-VC; NULL on error */
 struct gprs_ns2_vc *gprs_ns2_ip_bind_connect(struct gprs_ns2_vc_bind *bind,
 					     struct gprs_ns2_nse *nse,
-					     struct osmo_sockaddr *remote)
+					     const struct osmo_sockaddr *remote)
 {
 	struct gprs_ns2_vc *nsvc;
 	struct priv_vc *priv;
diff --git a/src/gb/gprs_ns2_vty.c b/src/gb/gprs_ns2_vty.c
index c6c4b02..55e87ae 100644
--- a/src/gb/gprs_ns2_vty.c
+++ b/src/gb/gprs_ns2_vty.c
@@ -707,7 +707,8 @@
  * \param[in] default_bind set the default address to bind to. Can be NULL.
  * \return 0 on success
  */
-int gprs_ns2_vty_init(struct gprs_ns2_inst *nsi, struct osmo_sockaddr_str *default_bind)
+int gprs_ns2_vty_init(struct gprs_ns2_inst *nsi,
+		      const struct osmo_sockaddr_str *default_bind)
 {
 	static bool vty_elements_installed = false;