diff --git a/binlog.c b/binlog.c
index 9c4558d..70f6ff8 100644
--- a/binlog.c
+++ b/binlog.c
@@ -1212,6 +1212,7 @@ static void create_new_binlog (void) {
 
 
 void tgl_replay_log (void) {
+  if (!tgl_state.binlog_enabled) { return; }
   if (access (get_binlog_file_name (), F_OK) < 0) {
     printf ("No binlog found. Creating new one\n");
     create_new_binlog ();
@@ -1413,7 +1414,7 @@ void bl_do_user_set_friend (struct tgl_user *U, int friend) {
 }
 
 void bl_do_dc_option (int id, int l1, const char *name, int l2, const char *ip, int port) {
-  struct dc *DC = tgl_state.DC_list[id];
+  struct tgl_dc *DC = tgl_state.DC_list[id];
   if (DC) { return; }
   
   clear_packet ();
@@ -1921,3 +1922,14 @@ void bl_do_msg_update (long long id) {
   out_long (id);
   add_log_event (packet_buffer, 4 * (packet_ptr - packet_buffer));
 }
+
+/*void bl_do_add_dc (int id, const char *ip, int l, int port, long long auth_key_id, const char *auth_key) {
+  clear_packet ();
+  out_int (CODE_binlog_add_dc);
+  out_long (id);
+  out_cstring (ip, l);
+  out_int (port);
+  out_long (auth_key_id);
+  out_ints ((void *)auth_key, 64);
+  add_log_event (packet_buffer, 4 * (packet_ptr - packet_buffer));
+}*/
diff --git a/binlog.h b/binlog.h
index cdaaa29..9393c2c 100644
--- a/binlog.h
+++ b/binlog.h
@@ -86,4 +86,6 @@ void bl_do_delete_msg (struct tgl_message *M);
 
 void bl_do_msg_seq_update (long long id);
 void bl_do_msg_update (long long id);
+
+//void bl_do_add_dc (int id, const char *ip, int l, int port, long long auth_key_id, const char *auth_key);
 #endif
diff --git a/binlog.tl b/binlog.tl
index a63b018..0c0c71e 100644
--- a/binlog.tl
+++ b/binlog.tl
@@ -68,3 +68,5 @@ binlog.deleteMsg id:long = binlog.Update;
 
 binlog.msgSeqUpdate id:long = binlog.Update;
 binlog.msgUpdate id:long = binlog.Update;
+
+//binlog.addDc id:int ip:string port:int auth_key_id:long auth_key:64*[int] = binlog.Update;
diff --git a/config.h.in b/config.h.in
index f0315e0..dd0d841 100644
--- a/config.h.in
+++ b/config.h.in
@@ -21,6 +21,10 @@
 /* Define to 1 if you have the <lauxlib.h> header file. */
 #undef HAVE_LAUXLIB_H
 
+/* Define to 1 if you have the `AES_set_encrypt_key' library
+   (-lAES_set_encrypt_key). */
+#undef HAVE_LIBAES_SET_ENCRYPT_KEY
+
 /* Define to 1 if you have the `config' library (-lconfig). */
 #undef HAVE_LIBCONFIG
 
diff --git a/configure b/configure
index bf5cc3e..1809eef 100755
--- a/configure
+++ b/configure
@@ -3469,6 +3469,51 @@ _ACEOF
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ssl in -lAES_set_encrypt_key" >&5
+$as_echo_n "checking for ssl in -lAES_set_encrypt_key... " >&6; }
+if ${ac_cv_lib_AES_set_encrypt_key_ssl+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lAES_set_encrypt_key  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char ssl ();
+int
+main ()
+{
+return ssl ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_AES_set_encrypt_key_ssl=yes
+else
+  ac_cv_lib_AES_set_encrypt_key_ssl=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_AES_set_encrypt_key_ssl" >&5
+$as_echo "$ac_cv_lib_AES_set_encrypt_key_ssl" >&6; }
+if test "x$ac_cv_lib_AES_set_encrypt_key_ssl" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBAES_SET_ENCRYPT_KEY 1
+_ACEOF
+
+  LIBS="-lAES_set_encrypt_key $LIBS"
+
+fi
+
 EXTRA_LIBS=""
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for rl_save_prompt in -lreadline" >&5
diff --git a/interface.c b/interface.c
index b396af7..bbcd098 100644
--- a/interface.c
+++ b/interface.c
@@ -78,7 +78,6 @@ int readline_active;
 
 int log_level;
 
-
 char *line_ptr;
 
 int in_chat_mode;
diff --git a/loop.c b/loop.c
index fd8be3f..c99968e 100644
--- a/loop.c
+++ b/loop.c
@@ -50,6 +50,7 @@
 #include "loop.h"
 #include "lua-tg.h"
 #include "tgl.h"
+#include "binlog.h"
 
 int verbosity;
 
@@ -149,7 +150,7 @@ int main_loop (void) {
   return 0;
 }
 
-struct dc *cur_a_dc;
+struct tgl_dc *cur_a_dc;
 int is_authorized (void) {
   return tgl_authorized_dc (cur_a_dc);
 }
@@ -229,16 +230,127 @@ int wait_dialog_list;
 
 extern struct tgl_update_callback upd_cb;
 
+#define DC_SERIALIZED_MAGIC 0x868aa81d
+
+void write_dc (struct tgl_dc *DC, void *extra) {
+  int auth_file_fd = *(int *)extra;
+  if (!DC) { 
+    int x = 0;
+    assert (write (auth_file_fd, &x, 4) == 4);
+    return;
+  } else {
+    int x = 1;
+    assert (write (auth_file_fd, &x, 4) == 4);
+  }
+
+  assert (DC->has_auth);
+
+  assert (write (auth_file_fd, &DC->port, 4) == 4);
+  int l = strlen (DC->ip);
+  assert (write (auth_file_fd, &l, 4) == 4);
+  assert (write (auth_file_fd, DC->ip, l) == l);
+  assert (write (auth_file_fd, &DC->auth_key_id, 8) == 8);
+  assert (write (auth_file_fd, DC->auth_key, 256) == 256);
+}
+
+char *get_auth_key_filename (void);
+void write_auth_file (void) {
+  if (binlog_enabled) { return; }
+  int auth_file_fd = open (get_auth_key_filename (), O_CREAT | O_RDWR, 0600);
+  assert (auth_file_fd >= 0);
+  int x = DC_SERIALIZED_MAGIC;
+  assert (write (auth_file_fd, &x, 4) == 4);
+  assert (write (auth_file_fd, &tgl_state.max_dc_num, 4) == 4);
+  assert (write (auth_file_fd, &tgl_state.dc_working_num, 4) == 4);
+
+  tgl_dc_iterator_ex (write_dc, &auth_file_fd);
+
+  assert (write (auth_file_fd, &tgl_state.our_id, 4) == 4);
+  close (auth_file_fd);
+}
+
+void read_dc (int auth_file_fd, int id, unsigned ver) {
+  int port = 0;
+  assert (read (auth_file_fd, &port, 4) == 4);
+  int l = 0;
+  assert (read (auth_file_fd, &l, 4) == 4);
+  assert (l >= 0 && l < 100);
+  char ip[100];
+  assert (read (auth_file_fd, ip, l) == l);
+  ip[l] = 0;
+
+  long long auth_key_id;
+  static unsigned char auth_key[256];
+  assert (read (auth_file_fd, &auth_key_id, 8) == 8);
+  assert (read (auth_file_fd, auth_key, 256) == 256);
+
+  //bl_do_add_dc (id, ip, l, port, auth_key_id, auth_key);
+  bl_do_dc_option (id, 2, "DC", l, ip, port);
+  bl_do_set_auth_key_id (id, auth_key);
+  bl_do_dc_signed (id);
+}
+
+void empty_auth_file (void) {
+  char *ip = tgl_state.test_mode ? TG_SERVER_TEST : TG_SERVER;
+  bl_do_dc_option (1, 3, "DC1", strlen (ip), ip, 443);
+  bl_do_set_working_dc (1);
+}
+
+int need_dc_list_update;
+void read_auth_file (void) {
+  if (binlog_enabled) { return; }
+  int auth_file_fd = open (get_auth_key_filename (), O_CREAT | O_RDWR, 0600);
+  if (auth_file_fd < 0) {
+    empty_auth_file ();
+    return;
+  }
+  assert (auth_file_fd >= 0);
+  unsigned x;
+  unsigned m;
+  if (read (auth_file_fd, &m, 4) < 4 || (m != DC_SERIALIZED_MAGIC)) {
+    close (auth_file_fd);
+    empty_auth_file ();
+    return;
+  }
+  assert (read (auth_file_fd, &x, 4) == 4);
+  assert (x > 0);
+  int dc_working_num;
+  assert (read (auth_file_fd, &dc_working_num, 4) == 4);
+  
+  int i;
+  for (i = 0; i <= (int)x; i++) {
+    int y;
+    assert (read (auth_file_fd, &y, 4) == 4);
+    if (y) {
+      read_dc (auth_file_fd, i, m);
+    }
+  }
+  bl_do_set_working_dc (dc_working_num);
+  int our_id;
+  int l = read (auth_file_fd, &our_id, 4);
+  if (l < 4) {
+    assert (!l);
+  }
+  if (our_id) {
+    bl_do_set_our_id (our_id);
+  }
+  close (auth_file_fd);
+}
+
 int loop (void) {
   //on_start ();
   tgl_set_callback (&upd_cb);
   tgl_init ();
-
-  double t = tglt_get_double_time ();
-  logprintf ("replay log start\n");
-  tgl_replay_log ();
-  logprintf ("replay log end in %lf seconds\n", tglt_get_double_time () - t);
-  tgl_reopen_binlog_for_writing ();
+ 
+  if (binlog_enabled) {
+    double t = tglt_get_double_time ();
+    logprintf ("replay log start\n");
+    tgl_replay_log ();
+    logprintf ("replay log end in %lf seconds\n", tglt_get_double_time () - t);
+    tgl_reopen_binlog_for_writing ();
+  } else {
+    read_auth_file ();
+  }
   binlog_read = 1;
   //exit (0);
   #ifdef USE_LUA
@@ -357,10 +469,11 @@ int loop (void) {
 
   for (i = 0; i <= tgl_state.max_dc_num; i++) if (tgl_state.DC_list[i] && !tgl_signed_dc (tgl_state.DC_list[i])) {
     tgl_do_export_auth (i, export_auth_callback, (void*)(long)tgl_state.DC_list[i]);    
-    cur_a_dc = tgl_state.DC_working;
+    cur_a_dc = tgl_state.DC_list[i];
     net_loop (0, dc_signed_in);
+    assert (tgl_signed_dc (tgl_state.DC_list[i]));
   }
-  //write_auth_file ();
+  write_auth_file ();
 
   fflush (stdout);
   fflush (stderr);
diff --git a/main.c b/main.c
index 308421c..cf9eb77 100644
--- a/main.c
+++ b/main.c
@@ -269,7 +269,7 @@ void parse_config_val (config_t *conf, char **s, char *param_name, const char *d
       *s = tstrdup (r);
     }
   } else {
-    if (path) {
+    if (path && default_name) {
       tasprintf (s, "%s/%s", path, default_name);
     } else {
       *s  = default_name ? tstrdup (default_name) : 0;
diff --git a/mtproto-client.c b/mtproto-client.c
index 43be3a7..51a4f50 100644
--- a/mtproto-client.c
+++ b/mtproto-client.c
@@ -76,7 +76,7 @@
 
 //int verbosity;
 static int auth_success;
-//static enum dc_state c_state;
+//static enum tgl_dc_state c_state;
 static char nonce[256];
 static char new_nonce[256];
 static char server_nonce[256];
@@ -231,7 +231,7 @@ static int rpc_send_message (struct connection *c, void *data, int len) {
 }
 
 static int send_req_pq_packet (struct connection *c) {
-  struct dc *D = tgl_state.net_methods->get_dc (c);
+  struct tgl_dc *D = tgl_state.net_methods->get_dc (c);
   assert (D->state == st_init);
 
   tglt_secure_random (nonce, 16);
@@ -555,7 +555,7 @@ static int process_dh_answer (struct connection *c, char *packet, int len) {
   assert (!memcmp (decrypt_buffer, sha1_buffer, 20));
   assert ((char *) in_end - (char *) in_ptr < 16);
 
-  struct dc *D = tgl_state.net_methods->get_dc (c);
+  struct tgl_dc *D = tgl_state.net_methods->get_dc (c);
   D->server_time_delta = server_time - time (0);
   D->server_time_udelta = server_time - get_utime (CLOCK_MONOTONIC);
   //logprintf ( "server time is %d, delta = %d\n", server_time, server_time_delta);
@@ -627,7 +627,7 @@ static int process_auth_complete (struct connection *c UU, char *packet, int len
   tmp[32] = 1;
   //GET_DC(c)->auth_key_id = *(long long *)(sha1_buffer + 12);
 
-  struct dc *D = tgl_state.net_methods->get_dc (c);
+  struct tgl_dc *D = tgl_state.net_methods->get_dc (c);
   bl_do_set_auth_key_id (D->id, (unsigned char *)D->auth_key);
   sha1 ((unsigned char *)D->auth_key, 256, sha1_buffer);
 
@@ -661,14 +661,14 @@ static struct encrypted_message enc_msg;
 
 static long long client_last_msg_id, server_last_msg_id;
 
-static double get_server_time (struct dc *DC) {
+static double get_server_time (struct tgl_dc *DC) {
   if (!DC->server_time_udelta) {
     DC->server_time_udelta = get_utime (CLOCK_REALTIME) - get_utime (CLOCK_MONOTONIC);
   }
   return get_utime (CLOCK_MONOTONIC) + DC->server_time_udelta;
 }
 
-static long long generate_next_msg_id (struct dc *DC) {
+static long long generate_next_msg_id (struct tgl_dc *DC) {
   long long next_id = (long long) (get_server_time (DC) * (1LL << 32)) & -4;
   if (next_id <= client_last_msg_id) {
     next_id = client_last_msg_id += 4;
@@ -678,8 +678,8 @@ static long long generate_next_msg_id (struct dc *DC) {
   return next_id;
 }
 
-static void init_enc_msg (struct session *S, int useful) {
-  struct dc *DC = S->dc;
+static void init_enc_msg (struct tgl_session *S, int useful) {
+  struct tgl_dc *DC = S->dc;
   assert (DC->auth_key_id);
   enc_msg.auth_key_id = DC->auth_key_id;
 //  assert (DC->server_salt);
@@ -699,7 +699,7 @@ static void init_enc_msg (struct session *S, int useful) {
   S->seq_no += 2;
 };
 
-static int aes_encrypt_message (struct dc *DC, struct encrypted_message *enc) {
+static int aes_encrypt_message (struct tgl_dc *DC, struct encrypted_message *enc) {
   unsigned char sha1_buffer[20];
   const int MINSZ = offsetof (struct encrypted_message, message);
   const int UNENCSZ = offsetof (struct encrypted_message, server_salt);
@@ -715,8 +715,8 @@ static int aes_encrypt_message (struct dc *DC, struct encrypted_message *enc) {
 }
 
 long long tglmp_encrypt_send_message (struct connection *c, int *msg, int msg_ints, int useful) {
-  struct dc *DC = tgl_state.net_methods->get_dc (c);
-  struct session *S = tgl_state.net_methods->get_session (c);
+  struct tgl_dc *DC = tgl_state.net_methods->get_dc (c);
+  struct tgl_session *S = tgl_state.net_methods->get_session (c);
   assert (S);
 
   const int UNENCSZ = offsetof (struct encrypted_message, server_salt);
@@ -928,7 +928,7 @@ static int process_rpc_message (struct connection *c UU, struct encrypted_messag
   const int UNENCSZ = offsetof (struct encrypted_message, server_salt);
   vlogprintf (E_DEBUG, "process_rpc_message(), len=%d\n", len);  
   assert (len >= MINSZ && (len & 15) == (UNENCSZ & 15));
-  struct dc *DC = tgl_state.net_methods->get_dc (c);
+  struct tgl_dc *DC = tgl_state.net_methods->get_dc (c);
   assert (enc->auth_key_id == DC->auth_key_id);
   assert (DC->auth_key_id);
   tgl_init_aes_auth (DC->auth_key + 8, enc->msg_key, AES_DECRYPT);
@@ -972,7 +972,7 @@ static int process_rpc_message (struct connection *c UU, struct encrypted_messag
   in_ptr = enc->message;
   in_end = in_ptr + (enc->msg_len / 4);
  
-  struct session *S = tgl_state.net_methods->get_session (c);
+  struct tgl_session *S = tgl_state.net_methods->get_session (c);
   if (enc->msg_id & 1) {
     tgln_insert_msg_id (S, enc->msg_id);
   }
@@ -1004,7 +1004,7 @@ static int rpc_execute (struct connection *c, int op, int len) {
 #if !defined(__MACH__) && !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined (__CYGWIN__)
 //  setsockopt (c->fd, IPPROTO_TCP, TCP_QUICKACK, (int[]){0}, 4);
 #endif
-  struct dc *D = tgl_state.net_methods->get_dc (c);
+  struct tgl_dc *D = tgl_state.net_methods->get_dc (c);
   int o = D->state;
   if (D->flags & 1) { o = st_authorized;}
   switch (o) {
@@ -1059,7 +1059,7 @@ static int tc_becomes_ready (struct connection *c) {
 #if !defined(__MACH__) && !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined (__CYGWIN__)
 //  setsockopt (c->fd, IPPROTO_TCP, TCP_QUICKACK, (int[]){0}, 4);
 #endif
-  struct dc *D = tgl_state.net_methods->get_dc (c);
+  struct tgl_dc *D = tgl_state.net_methods->get_dc (c);
   int o = D->state;
   if (D->flags & 1) { o = st_authorized; }
   switch (o) {
@@ -1108,7 +1108,7 @@ void tglmp_on_start (const char *key) {
 //  return auth_success;
 //}
 
-void tgl_dc_authorize (struct dc *DC) {
+void tgl_dc_authorize (struct tgl_dc *DC) {
   //c_state = 0;
   //auth_success = 0;
   if (!DC->sessions[0]) {
@@ -1121,7 +1121,7 @@ void tgl_dc_authorize (struct dc *DC) {
 #define long_cmp(a,b) ((a) > (b) ? 1 : (a) == (b) ? 0 : -1)
 DEFINE_TREE(long,long long,long_cmp,0)
 
-static int send_all_acks (struct session *S) {
+static int send_all_acks (struct tgl_session *S) {
   clear_packet ();
   out_int (CODE_msgs_ack);
   out_int (CODE_vector);
@@ -1140,7 +1140,7 @@ static void send_all_acks_gateway (evutil_socket_t fd, short what, void *arg) {
 }
 
 
-void tgln_insert_msg_id (struct session *S, long long id) {
+void tgln_insert_msg_id (struct tgl_session *S, long long id) {
   if (!S->ack_tree) {
     static struct timeval ptimeout = { ACK_TIMEOUT, 0};
     event_add (S->ev, &ptimeout);
@@ -1150,11 +1150,11 @@ void tgln_insert_msg_id (struct session *S, long long id) {
   }
 }
 
-//extern struct dc *DC_list[];
+//extern struct tgl_dc *DC_list[];
 
-struct dc *tglmp_alloc_dc (int id, char *ip, int port UU) {
+struct tgl_dc *tglmp_alloc_dc (int id, char *ip, int port UU) {
   assert (!tgl_state.DC_list[id]);
-  struct dc *DC = talloc0 (sizeof (*DC));
+  struct tgl_dc *DC = talloc0 (sizeof (*DC));
   DC->id = id;
   DC->ip = ip;
   DC->port = port;
@@ -1171,8 +1171,8 @@ static struct mtproto_methods mtproto_methods = {
   .close = rpc_close
 };
 
-void tglmp_dc_create_session (struct dc *DC) {
-  struct session *S = talloc0 (sizeof (*S));
+void tglmp_dc_create_session (struct tgl_dc *DC) {
+  struct tgl_session *S = talloc0 (sizeof (*S));
   assert (RAND_pseudo_bytes ((unsigned char *) &S->session_id, 8) >= 0);
   S->dc = DC;
   S->c = tgl_state.net_methods->create_connection (DC->ip, DC->port, S, DC, &mtproto_methods);
@@ -1191,3 +1191,17 @@ void tgl_do_send_ping (struct connection *c) {
   *(long long *)(x + 1) = lrand48 () * (1ll << 32) + lrand48 ();
   tglmp_encrypt_send_message (c, x, 3, 0);
 }
+
+void tgl_dc_iterator (void (*iterator)(struct tgl_dc *DC)) {
+  int i;
+  for (i = 0; i <= tgl_state.max_dc_num; i++) {
+    iterator (tgl_state.DC_list[i]);
+  }
+}
+
+void tgl_dc_iterator_ex (void (*iterator)(struct tgl_dc *DC, void *extra), void *extra) {
+  int i;
+  for (i = 0; i <= tgl_state.max_dc_num; i++) {
+    iterator (tgl_state.DC_list[i], extra);
+  }
+}
diff --git a/mtproto-client.h b/mtproto-client.h
index b4bd80c..77e573c 100644
--- a/mtproto-client.h
+++ b/mtproto-client.h
@@ -23,7 +23,7 @@
 #include <openssl/bn.h>
 //void on_start (void);
 //..long long encrypt_send_message (struct connection *c, int *msg, int msg_ints, int useful);
-//void dc_authorize (struct dc *DC);
+//void dc_authorize (struct tgl_dc *DC);
 //void work_update (struct connection *c, long long msg_id);
 //void work_update_binlog (void);
 //int check_g (unsigned char p[256], BIGNUM *g);
@@ -31,11 +31,11 @@
 //int check_DH_params (BIGNUM *p, int g);
 //void secure_random (void *s, int l);
 
+#include "tgl.h"
+
 struct connection;
-struct dc;
+struct tgl_dc;
 //#include "queries.h"
-#define TG_SERVER "173.240.5.1"
-#define TG_SERVER_TEST "173.240.5.253"
 #define TG_APP_HASH "36722c72256a24c1225de00eb6a1ca74"
 #define TG_APP_ID 2899
 
@@ -44,51 +44,13 @@ struct dc;
 
 struct connection;
 
-enum dc_state {
-  st_init,
-  st_reqpq_sent,
-  st_reqdh_sent,
-  st_client_dh_sent,
-  st_authorized,
-  st_error
-};
-
-#define MAX_DC_SESSIONS 3
-
-struct session {
-  struct dc *dc;
-  long long session_id;
-  int seq_no;
-  struct connection *c;
-  struct tree_long *ack_tree;
-  struct event *ev;
-  //struct event_timer ev;
-};
-
-struct dc {
-  int id;
-  int port;
-  int flags;
-  enum dc_state state;
-  char *ip;
-  char *user;
-  struct session *sessions[MAX_DC_SESSIONS];
-  char auth_key[256];
-  long long auth_key_id;
-  long long server_salt;
-
-  int server_time_delta;
-  double server_time_udelta;
-  int has_auth;
-};
-
 long long tglmp_encrypt_send_message (struct connection *c, int *msg, int msg_ints, int useful);
-void tglmp_dc_create_session (struct dc *DC);
+void tglmp_dc_create_session (struct tgl_dc *DC);
 int tglmp_check_g (unsigned char p[256], BIGNUM *g);
 int tglmp_check_DH_params (BIGNUM *p, int g);
-struct dc *tglmp_alloc_dc (int id, char *ip, int port);
+struct tgl_dc *tglmp_alloc_dc (int id, char *ip, int port);
 
-void tgln_insert_msg_id (struct session *S, long long id);
+void tgln_insert_msg_id (struct tgl_session *S, long long id);
 void tglmp_on_start (const char *key);
-void tgl_dc_authorize (struct dc *DC);
+void tgl_dc_authorize (struct tgl_dc *DC);
 #endif
diff --git a/net.c b/net.c
index 054d990..0ab60f7 100644
--- a/net.c
+++ b/net.c
@@ -251,7 +251,7 @@ static void conn_try_write (evutil_socket_t fd, short what, void *arg) {
   }
 }
 
-struct connection *tgln_create_connection (const char *host, int port, struct session *session, struct dc *dc, struct mtproto_methods *methods) {
+struct connection *tgln_create_connection (const char *host, int port, struct tgl_session *session, struct tgl_dc *dc, struct mtproto_methods *methods) {
   struct connection *c = talloc0 (sizeof (*c));
   int fd = socket (AF_INET, SOCK_STREAM, 0);
   if (fd == -1) {
@@ -588,11 +588,11 @@ static void incr_out_packet_num (struct connection *c) {
   c->out_packet_num ++;
 }
 
-static struct dc *get_dc (struct connection *c) {
+static struct tgl_dc *get_dc (struct connection *c) {
   return c->dc;
 }
 
-static struct session *get_session (struct connection *c) {
+static struct tgl_session *get_session (struct connection *c) {
   return c->session;
 }
 
diff --git a/net.h b/net.h
index ca90624..667bd7c 100644
--- a/net.h
+++ b/net.h
@@ -26,7 +26,7 @@
 #define STATE_FILE_MAGIC 0x84217a0d
 #define SECRET_CHAT_FILE_MAGIC 0xa9840add
 
-struct dc_serialized {
+struct tgl_dc_serialized {
   int magic;
   int port;
   char ip[64];
@@ -70,8 +70,8 @@ struct connection {
   int last_connect_time;
   int in_fail_timer;
   struct mtproto_methods *methods;
-  struct session *session;
-  struct dc *dc;
+  struct tgl_session *session;
+  struct tgl_dc *dc;
   void *extra;
   struct event *ping_ev;
   struct event *fail_ev;
@@ -87,16 +87,16 @@ void tgln_flush_out (struct connection *c);
 int tgln_read_in (struct connection *c, void *data, int len);
 int tgln_read_in_lookup (struct connection *c, void *data, int len);
 
-void tgln_insert_msg_id (struct session *S, long long id);
+void tgln_insert_msg_id (struct tgl_session *S, long long id);
 
 extern struct tgl_net_methods tgl_conn_methods;
 
 //void create_all_outbound_connections (void);
 
-//struct connection *create_connection (const char *host, int port, struct session *session, struct connection_methods *methods);
-struct dc *tgln_alloc_dc (int id, char *ip, int port);
-void tgln_dc_create_session (struct dc *DC, struct mtproto_methods *methods);
-struct connection *tgln_create_connection (const char *host, int port, struct session *session, struct dc *dc, struct mtproto_methods *methods);
+//struct connection *create_connection (const char *host, int port, struct tgl_session *session, struct connection_methods *methods);
+struct tgl_dc *tgln_alloc_dc (int id, char *ip, int port);
+void tgln_dc_create_session (struct tgl_dc *DC, struct mtproto_methods *methods);
+struct connection *tgln_create_connection (const char *host, int port, struct tgl_session *session, struct tgl_dc *dc, struct mtproto_methods *methods);
 
 #define GET_DC(c) (c->session->dc)
 #endif
diff --git a/queries.c b/queries.c
index c8404ce..fa93689 100644
--- a/queries.c
+++ b/queries.c
@@ -125,7 +125,7 @@ static void alarm_query_gateway (evutil_socket_t fd, short what, void *arg) {
 }
 
 
-struct query *tglq_send_query (struct dc *DC, int ints, void *data, struct query_methods *methods, void *extra, void *callback, void *callback_extra) {
+struct query *tglq_send_query (struct tgl_dc *DC, int ints, void *data, struct query_methods *methods, void *extra, void *callback, void *callback_extra) {
   assert (DC);
   assert (DC->auth_key_id);
   if (!DC->sessions[0]) {
@@ -275,8 +275,8 @@ void tglq_query_result (long long id UU) {
 //int max_bcast_size;
 //int want_dc_num;
 //int new_dc_num;
-//extern struct dc *DC_list[];
-//extern struct dc *tgl_state.DC_working;
+//extern struct tgl_dc *DC_list[];
+//extern struct tgl_dc *tgl_state.DC_working;
 
 static void out_random (int n) {
   assert (n <= 32);
@@ -2184,7 +2184,7 @@ static int import_auth_on_answer (struct query *q UU) {
   fetch_int (); // expires
   tglf_fetch_alloc_user ();
   
-  bl_do_dc_signed (((struct dc *)q->extra)->id);
+  bl_do_dc_signed (((struct tgl_dc *)q->extra)->id);
 
   if (q->callback) {
     ((void (*)(void *, int))q->callback) (q->callback_extra, 1);
diff --git a/queries.h b/queries.h
index b908a3b..91b0588 100644
--- a/queries.h
+++ b/queries.h
@@ -43,15 +43,15 @@ struct query {
   void *data;
   struct query_methods *methods;
   struct event *ev;
-  struct dc *DC;
-  struct session *session;
+  struct tgl_dc *DC;
+  struct tgl_session *session;
   void *extra;
   void *callback;
   void *callback_extra;
 };
 
 
-struct query *tglq_send_query (struct dc *DC, int len, void *data, struct query_methods *methods, void *extra, void *callback, void *callback_extra);
+struct query *tglq_send_query (struct tgl_dc *DC, int len, void *data, struct query_methods *methods, void *extra, void *callback, void *callback_extra);
 void tglq_query_ack (long long id);
 void tglq_query_error (long long id);
 void tglq_query_result (long long id);
diff --git a/tgl-layout.h b/tgl-layout.h
index cf15aae..5a830c7 100644
--- a/tgl-layout.h
+++ b/tgl-layout.h
@@ -22,6 +22,44 @@
 
 typedef struct { int type; int id; } tgl_peer_id_t;
 
+enum tgl_dc_state {
+  st_init,
+  st_reqpq_sent,
+  st_reqdh_sent,
+  st_client_dh_sent,
+  st_authorized,
+  st_error
+};
+
+#define MAX_DC_SESSIONS 3
+
+struct tgl_session {
+  struct tgl_dc *dc;
+  long long session_id;
+  int seq_no;
+  struct connection *c;
+  struct tree_long *ack_tree;
+  struct event *ev;
+  //struct event_timer ev;
+};
+
+struct tgl_dc {
+  int id;
+  int port;
+  int flags;
+  enum tgl_dc_state state;
+  char *ip;
+  char *user;
+  struct tgl_session *sessions[MAX_DC_SESSIONS];
+  char auth_key[256];
+  long long auth_key_id;
+  long long server_salt;
+
+  int server_time_delta;
+  double server_time_udelta;
+  int has_auth;
+};
+
 enum tgl_message_media_type {
   tgl_message_media_none,
   tgl_message_media_photo,
diff --git a/tgl.c b/tgl.c
index 594bd78..403f698 100644
--- a/tgl.c
+++ b/tgl.c
@@ -51,12 +51,12 @@ void tgl_init (void) {
   tglmp_on_start (tgl_state.rsa_key);
 }
 
-int tgl_authorized_dc (struct dc *DC) {
+int tgl_authorized_dc (struct tgl_dc *DC) {
   assert (DC);
   return DC->auth_key_id;
 }
 
-int tgl_signed_dc (struct dc *DC) {
+int tgl_signed_dc (struct tgl_dc *DC) {
   assert (DC);
   return DC->has_auth;
 }
diff --git a/tgl.h b/tgl.h
index 59b4d2b..ad11d1c 100644
--- a/tgl.h
+++ b/tgl.h
@@ -5,6 +5,8 @@
 #include <string.h>
 
 #define TGL_MAX_DC_NUM 100
+#define TG_SERVER "173.240.5.1"
+#define TG_SERVER_TEST "173.240.5.253"
 
 // JUST RANDOM STRING
 #define TGL_BUILD "1828"
@@ -12,8 +14,8 @@
 
 struct connection;
 struct mtproto_methods;
-struct session;
-struct dc;
+struct tgl_session;
+struct tgl_dc;
 struct bingnum_ctx;
 
 #define TGL_UPDATE_CREATED 1
@@ -79,10 +81,10 @@ struct tgl_net_methods {
   int (*read_in_lookup) (struct connection *c, void *data, int len);
   void (*flush_out) (struct connection *c);
   void (*incr_out_packet_num) (struct connection *c);
-  struct dc *(*get_dc) (struct connection *c);
-  struct session *(*get_session) (struct connection *c);
+  struct tgl_dc *(*get_dc) (struct connection *c);
+  struct tgl_session *(*get_session) (struct connection *c);
 
-  struct connection *(*create_connection) (const char *host, int port, struct session *session, struct dc *dc, struct mtproto_methods *methods);
+  struct connection *(*create_connection) (const char *host, int port, struct tgl_session *session, struct tgl_dc *dc, struct mtproto_methods *methods);
 };
 
 
@@ -109,8 +111,8 @@ struct tgl_state {
   int unread_messages;
 
   long long locks; 
-  struct dc *DC_list[TGL_MAX_DC_NUM];
-  struct dc *DC_working;
+  struct tgl_dc *DC_list[TGL_MAX_DC_NUM];
+  struct tgl_dc *DC_working;
   int max_dc_num;
   int dc_working_num;
 
@@ -246,8 +248,8 @@ void tgl_do_visualize_key (tgl_peer_id_t id, unsigned char buf[16]);
 
 void tgl_do_send_ping (struct connection *c);
 
-int tgl_authorized_dc (struct dc *DC);
-int tgl_signed_dc (struct dc *DC);
+int tgl_authorized_dc (struct tgl_dc *DC);
+int tgl_signed_dc (struct tgl_dc *DC);
 
 //void tgl_do_get_suggested (void);
 
@@ -261,8 +263,12 @@ struct mtproto_methods {
 };
 
 void tgl_init (void);
-void tgl_dc_authorize (struct dc *DC);
+void tgl_dc_authorize (struct tgl_dc *DC);
 
+void tgl_dc_iterator (void (*iterator)(struct tgl_dc *DC));
+void tgl_dc_iterator_ex (void (*iterator)(struct tgl_dc *DC, void *extra), void *extra);
 
 double tglt_get_double_time (void);
+
+
 #endif