diff --git a/include/re_sip.h b/include/re_sip.h
index 8250911..e6dd358 100644
--- a/include/re_sip.h
+++ b/include/re_sip.h
@@ -234,6 +234,8 @@ int  sip_alloc(struct sip **sipp, struct dnsc *dnsc, uint32_t ctsz,
 int  sip_transp_add(struct sip *sip, enum sip_transp tp,
 		    const struct sa *laddr, ...);
 void sip_transp_flush(struct sip *sip);
+bool sip_transp_isladdr(const struct sip *sip, enum sip_transp tp,
+			const struct sa *laddr);
 void sip_close(struct sip *sip, bool force);
 int  sip_listen(struct sip_lsnr **lsnrp, struct sip *sip, bool req,
 		sip_msg_h *msgh, void *arg);
diff --git a/src/sip/transp.c b/src/sip/transp.c
index 97b0b07..c8ee2c9 100644
--- a/src/sip/transp.c
+++ b/src/sip/transp.c
@@ -771,6 +771,31 @@ bool sip_transp_supported(struct sip *sip, enum sip_transp tp, int af)
 }
 
 
+bool sip_transp_isladdr(const struct sip *sip, enum sip_transp tp,
+			const struct sa *laddr)
+{
+	struct le *le;
+
+	if (!sip || !laddr)
+		return false;
+
+	for (le=sip->transpl.head; le; le=le->next) {
+
+		const struct sip_transport *transp = le->data;
+
+		if (tp != SIP_TRANSP_NONE && transp->tp != tp)
+			continue;
+
+		if (!sa_cmp(&transp->laddr, laddr, SA_ALL))
+			continue;
+
+		return true;
+	}
+
+	return false;
+}
+
+
 const char *sip_transp_name(enum sip_transp tp)
 {
 	switch (tp) {