diff --git a/include/osmocom/abis/e1_input.h b/include/osmocom/abis/e1_input.h
index a9b6178..d2033ef 100644
--- a/include/osmocom/abis/e1_input.h
+++ b/include/osmocom/abis/e1_input.h
@@ -116,6 +116,7 @@
 	const char *name;
 	int (*want_write)(struct e1inp_ts *ts);
 	int (*line_update)(struct e1inp_line *line, enum e1inp_line_role role, const char *addr);
+	void (*close)(struct e1inp_ts *ts);
 	int default_delay;
 };
 
@@ -123,9 +124,9 @@
 	enum e1inp_line_role	role;
 	char			*addr;
 
-	int	(*sign_link_up)(struct msgb *msg, struct e1inp_line *line, enum e1inp_sign_type type);
-	int	(*sign_link)(struct msgb *msg, struct e1inp_line *line, struct e1inp_sign_link *link);
-	int	(*error)(struct msgb *msg, struct e1inp_line *line, enum e1inp_sign_type type, int error);
+	struct e1inp_sign_link *	(*sign_link_up)(void *unit_info, struct e1inp_line *line, enum e1inp_sign_type type);
+	void	(*sign_link_down)(struct e1inp_line *line);
+	int	(*sign_link)(struct msgb *msg, struct e1inp_sign_link *link);
 };
 
 struct e1inp_line {
diff --git a/include/osmocom/abis/ipa.h b/include/osmocom/abis/ipa.h
index f088ec0..d455069 100644
--- a/include/osmocom/abis/ipa.h
+++ b/include/osmocom/abis/ipa.h
@@ -42,19 +42,22 @@
 
 struct ipa_client_link {
 	struct e1inp_line		*line;
-	struct osmo_fd			ofd;
+	struct osmo_fd			*ofd;
 	struct llist_head		tx_queue;
 	struct osmo_timer_list		timer;
 	enum ipa_client_link_state	state;
 	const char			*addr;
 	uint16_t			port;
-	int (*cb)(struct ipa_client_link *link, struct msgb *msg);
+	int (*read_cb)(struct ipa_client_link *link, struct msgb *msg);
+	int (*write_cb)(struct ipa_client_link *link);
 	void				*data;
 };
 
-struct ipa_client_link *ipa_client_link_create(void *ctx, struct e1inp_line *line, const char *addr, uint16_t port, int (*cb)(struct ipa_client_link *link, struct msgb *msgb), void *data);
+struct ipa_client_link *ipa_client_link_create(void *ctx, struct e1inp_ts *ts, const char *driver_name, int priv_nr, const char *addr, uint16_t port, int (*read_cb)(struct ipa_client_link *link, struct msgb *msgb), int (*write_cb)(struct ipa_client_link *link), void *data);
 void ipa_client_link_destroy(struct ipa_client_link *link);
 
+int ipa_client_write_default_cb(struct ipa_client_link *link);
+
 int ipa_client_link_open(struct ipa_client_link *link);
 void ipa_client_link_close(struct ipa_client_link *link);
 
diff --git a/include/osmocom/abis/ipaccess.h b/include/osmocom/abis/ipaccess.h
index 2792572..d4174a8 100644
--- a/include/osmocom/abis/ipaccess.h
+++ b/include/osmocom/abis/ipaccess.h
@@ -90,4 +90,14 @@
 	uint32_t start;
 } __attribute__((packed));
 
+struct ipaccess_unit {
+	uint16_t site_id;
+	uint16_t bts_id;
+	uint16_t trx_id;
+};
+
+struct hsl_unit {
+	unsigned long serno;
+};
+
 #endif /* _OSMO_PROTO_IPACCESS_H */