int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
snat_protocol_t proto, u32 vrf_id, int is_in);
int nat44_del_ed_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
snat_protocol_t proto, u32 vrf_id, int is_in);
int nat44_del_ed_session (snat_main_t *sm, ip4_address_t *addr, u16 port,