diff --git a/include/patty/ax25/sock.h b/include/patty/ax25/sock.h
index 3714e7c..3c04393 100644
--- a/include/patty/ax25/sock.h
+++ b/include/patty/ax25/sock.h
@@ -1,12 +1,10 @@
 #ifndef _PATTY_AX25_SOCK_H
 #define _PATTY_AX25_SOCK_H
 
-#define PATTY_AX25_SOCK_RX_MAXLEN 4096
-#define PATTY_AX25_SOCK_RX_WINDOW  127
-
-#define PATTY_AX25_SOCK_DEFAULT_MAXLEN 256
-#define PATTY_AX25_SOCK_DEFAULT_RETRY   10
-#define PATTY_AX25_SOCK_DEFAULT_WINDOW   8
+#define PATTY_AX25_SOCK_DEFAULT_MAXLEN 4096
+#define PATTY_AX25_SOCK_DEFAULT_WINDOW  127
+#define PATTY_AX25_SOCK_DEFAULT_RETRY    10
+#define PATTY_AX25_SOCK_DEFAULT_ACK    3000
 
 enum patty_ax25_sock_type {
     PATTY_AX25_SOCK_STREAM,
@@ -54,6 +52,7 @@ typedef struct _patty_ax25_sock {
            n_maxlen_rx,
            n_window_tx,
            n_window_rx,
+           n_ack,
            n_retry;
 
     unsigned int seq_send,
diff --git a/src/sock.c b/src/sock.c
index 9f52eee..e2178c5 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -79,14 +79,10 @@ patty_ax25_sock *patty_ax25_sock_new(enum patty_ax25_proto proto,
 
     memset(sock, '\0', sizeof(*sock));
 
-    sock->proto       = proto;
-    sock->type        = type;
-    sock->status      = PATTY_AX25_SOCK_CLOSED;
-    sock->mode        = PATTY_AX25_SOCK_DM;
-    sock->n_maxlen_tx = PATTY_AX25_SOCK_DEFAULT_MAXLEN;
-    sock->n_maxlen_rx = PATTY_AX25_SOCK_RX_MAXLEN;
-    sock->n_window_tx = PATTY_AX25_SOCK_DEFAULT_WINDOW;
-    sock->n_window_rx = PATTY_AX25_SOCK_RX_WINDOW;
+    patty_ax25_sock_reset(sock);
+
+    sock->proto = proto;
+    sock->type  = type;
 
     if ((sock->buf = malloc(PATTY_AX25_FRAME_OVERHEAD + sock->n_maxlen_rx)) == NULL) {
         goto error_malloc_buf;
@@ -119,9 +115,11 @@ void patty_ax25_sock_reset(patty_ax25_sock *sock) {
     sock->status          = PATTY_AX25_SOCK_CLOSED;
     sock->mode            = PATTY_AX25_SOCK_DM;
     sock->n_maxlen_tx     = PATTY_AX25_SOCK_DEFAULT_MAXLEN;
-    sock->n_maxlen_rx     = PATTY_AX25_SOCK_RX_MAXLEN;
+    sock->n_maxlen_rx     = PATTY_AX25_SOCK_DEFAULT_MAXLEN;
+    sock->n_window_tx     = PATTY_AX25_SOCK_DEFAULT_WINDOW;
+    sock->n_window_tx     = PATTY_AX25_SOCK_DEFAULT_WINDOW;
+    sock->n_ack           = PATTY_AX25_SOCK_DEFAULT_ACK;
     sock->n_retry         = PATTY_AX25_SOCK_DEFAULT_RETRY;
-    sock->n_window_tx     = PATTY_AX25_SOCK_RX_WINDOW;
     sock->timer_ack       = 0;
     sock->timer_response  = 0;
     sock->timer_keepalive = 0;