diff --git a/src/mod_sip_proxy.erl b/src/mod_sip_proxy.erl
index b05c49061..185d72afe 100644
--- a/src/mod_sip_proxy.erl
+++ b/src/mod_sip_proxy.erl
@@ -66,15 +66,15 @@ wait_for_request({#sip{type = request} = Req, TrID}, State) ->
     Opts = State#state.opts,
     Req1 = prepare_request(State#state.host, Req),
     case connect(Req1, Opts) of
-	{ok, SIPSockets} ->
+	{ok, SIPSocketsWithURIs} ->
 	    NewState =
 		lists:foldl(
-		  fun(_SIPSocket, {error, _} = Err) ->
+		  fun(_SIPSocketWithURI, {error, _} = Err) ->
 			  Err;
-		     (SIPSocket, #state{tr_ids = TrIDs} = AccState) ->
+		     ({SIPSocket, URI}, #state{tr_ids = TrIDs} = AccState) ->
 			  Req2 = add_record_route(SIPSocket, State#state.host, Req1),
 			  Req3 = add_via(SIPSocket, State#state.host, Req2),
-			  case esip:request(SIPSocket, Req3,
+			  case esip:request(SIPSocket, Req3#sip{uri = URI},
 					    {?MODULE, route, [self()]}) of
 			      {ok, ClientTrID} ->
 				  NewTrIDs = [ClientTrID|TrIDs],
@@ -83,7 +83,7 @@ wait_for_request({#sip{type = request} = Req, TrID}, State) ->
 				  cancel_pending_transactions(AccState),
 				  Err
 			  end
-		  end, State, SIPSockets),
+		  end, State, SIPSocketsWithURIs),
 	    case NewState of
 		{error, _} = Err ->
 		    {Status, Reason} = esip:error_status(Err),
@@ -214,7 +214,7 @@ connect(#sip{hdrs = Hdrs} = Req, Opts) ->
 	false ->
 	    case esip:connect(Req, Opts) of
 		{ok, SIPSock} ->
-		    {ok, [SIPSock]};
+		    {ok, [{SIPSock, Req#sip.uri}]};
 		{error, _} = Err ->
 		    Err
 	    end
diff --git a/src/mod_sip_registrar.erl b/src/mod_sip_registrar.erl
index 689efe48e..5080cf4a7 100644
--- a/src/mod_sip_registrar.erl
+++ b/src/mod_sip_registrar.erl
@@ -23,11 +23,13 @@
 -include("esip.hrl").
 
 -define(CALL_TIMEOUT, timer:seconds(30)).
+-define(DEFAULT_EXPIRES, 3600).
 
 -record(binding, {socket = #sip_socket{},
 		  call_id = <<"">> :: binary(),
 		  cseq = 0 :: non_neg_integer(),
 		  timestamp = now() :: erlang:timestamp(),
+		  contact :: {binary(), #uri{}, [{binary(), binary()}]},
 		  tref = make_ref() :: reference(),
 		  expires = 0 :: non_neg_integer()}).
 
@@ -50,20 +52,19 @@ request(#sip{hdrs = Hdrs} = Req, SIPSock) ->
     US = {LUser, LServer},
     CallID = esip:get_hdr('call-id', Hdrs),
     CSeq = esip:get_hdr('cseq', Hdrs),
-    Expires = esip:get_hdr('expires', Hdrs, 0),
+    Expires = esip:get_hdr('expires', Hdrs, ?DEFAULT_EXPIRES),
     case esip:get_hdrs('contact', Hdrs) of
         [<<"*">>] when Expires == 0 ->
-            case unregister_session(US, SIPSock, CallID, CSeq) of
-		ok ->
+            case unregister_session(US, CallID, CSeq) of
+		{ok, ContactsWithExpires} ->
 		    ?INFO_MSG("unregister SIP session for user ~s@~s from ~s",
 			      [LUser, LServer, inet_parse:ntoa(PeerIP)]),
-		    Contact = {<<"">>, #uri{user = LUser, host = LServer},
-			       [{<<"expires">>, <<"0">>}]},
+		    Cs = prepare_contacts_to_send(ContactsWithExpires),
 		    mod_sip:make_response(
 		      Req,
 		      #sip{type = response,
 			   status = 200,
-			   hdrs = [{'contact', [Contact]}]});
+			   hdrs = [{'contact', Cs}]});
 		{error, Why} ->
 		    {Status, Reason} = make_status(Why),
 		    mod_sip:make_response(
@@ -72,51 +73,35 @@ request(#sip{hdrs = Hdrs} = Req, SIPSock) ->
 				reason = Reason})
 	    end;
         [{_, _URI, _Params}|_] = Contacts ->
-            ExpiresList = lists:map(
-			    fun({_, _, Params}) ->
-				    case to_integer(
-					   esip:get_param(
-					     <<"expires">>, Params),
-					   0, (1 bsl 32)-1) of
-					{ok, E} -> E;
-					_ -> Expires
-				    end
-			    end, Contacts),
-	    Expires1 = lists:max(ExpiresList),
-	    Contact = {<<"">>, #uri{user = LUser, host = LServer},
-		       [{<<"expires">>, jlib:integer_to_binary(Expires1)}]},
+	    ContactsWithExpires = make_contacts_with_expires(Contacts, Expires),
+	    Expires1 = lists:max([E || {_, E} <- ContactsWithExpires]),
 	    MinExpires = min_expires(),
-            if Expires1 >= MinExpires ->
-		    case register_session(US, SIPSock, CallID, CSeq, Expires1) of
-			ok ->
-			    ?INFO_MSG("register SIP session for user ~s@~s from ~s",
-				      [LUser, LServer, inet_parse:ntoa(PeerIP)]),
+	    if Expires1 > 0, Expires1 < MinExpires ->
+		    mod_sip:make_response(
+		      Req, #sip{type = response,
+				status = 423,
+				hdrs = [{'min-expires', MinExpires}]});
+	       true ->
+		    case register_session(US, SIPSock, CallID, CSeq,
+					  ContactsWithExpires) of
+			{ok, Res} ->
+			    if Res == updated ->
+				    ?INFO_MSG("register SIP session for user "
+					      "~s@~s from ~s",
+					      [LUser, LServer,
+					       inet_parse:ntoa(PeerIP)]);
+			       Res == deleted ->
+				    ?INFO_MSG("unregister SIP session for user "
+					      "~s@~s from ~s",
+					      [LUser, LServer,
+					       inet_parse:ntoa(PeerIP)])
+			    end,
+			    Cs = prepare_contacts_to_send(ContactsWithExpires),
 			    mod_sip:make_response(
 			      Req,
 			      #sip{type = response,
 				   status = 200,
-				   hdrs = [{'contact', [Contact]}]});
-			{error, Why} ->
-			    {Status, Reason} = make_status(Why),
-			    mod_sip:make_response(
-			      Req, #sip{type = response,
-					status = Status,
-					reason = Reason})
-		    end;
-               Expires1 > 0, Expires1 < MinExpires ->
-                    mod_sip:make_response(
-		      Req, #sip{type = response,
-				status = 423,
-				hdrs = [{'min-expires', MinExpires}]});
-               true ->
-                    case unregister_session(US, SIPSock, CallID, CSeq) of
-			ok ->
-			    ?INFO_MSG("unregister SIP session for user ~s@~s from ~s",
-				      [LUser, LServer, inet_parse:ntoa(PeerIP)]),
-			    mod_sip:make_response(
-			      Req,
-			      #sip{type = response, status = 200,
-				   hdrs = [{'contact', [Contact]}]});
+				   hdrs = [{'contact', Cs}]});
 			{error, Why} ->
 			    {Status, Reason} = make_status(Why),
 			    mod_sip:make_response(
@@ -128,22 +113,15 @@ request(#sip{hdrs = Hdrs} = Req, SIPSock) ->
 	[] ->
 	    case mnesia:dirty_read(sip_session, US) of
 		[#sip_session{bindings = Bindings}] ->
-		    case pop_previous_binding(SIPSock, Bindings) of
-			{ok, #binding{expires = Expires1}, _} ->
-			    Contact = {<<"">>,
-				       #uri{user = LUser, host = LServer},
-				       [{<<"expires">>,
-					 jlib:integer_to_binary(Expires1)}]},
-			    mod_sip:make_response(
-			      Req, #sip{type = response, status = 200,
-					hdrs = [{'contact', [Contact]}]});
-			{error, notfound} ->
-			    {Status, Reason} = make_status(notfound),
-			    mod_sip:make_response(
-			      Req, #sip{type = response,
-					status = Status,
-					reason = Reason})
-		    end;
+		    ContactsWithExpires =
+			lists:map(
+			  fun(#binding{contact = Contact, expires = Es}) ->
+				  {Contact, Es}
+			  end, Bindings),
+		    Cs = prepare_contacts_to_send(ContactsWithExpires),
+		    mod_sip:make_response(
+		      Req, #sip{type = response, status = 200,
+				hdrs = [{'contact', Cs}]});
 		[] ->
 		    {Status, Reason} = make_status(notfound),
 		    mod_sip:make_response(
@@ -158,7 +136,11 @@ request(#sip{hdrs = Hdrs} = Req, SIPSock) ->
 find_sockets(U, S) ->
     case mnesia:dirty_read(sip_session, {U, S}) of
 	[#sip_session{bindings = Bindings}] ->
-	    [Binding#binding.socket || Binding <- Bindings];
+	    lists:map(
+	      fun(#binding{contact = {_, URI, _},
+			   socket = Socket}) ->
+		      {Socket, URI}
+	      end, Bindings);
 	[] ->
 	    []
     end.
@@ -176,8 +158,8 @@ init([]) ->
 handle_call({write, Session}, _From, State) ->
     Res = write_session(Session),
     {reply, Res, State};
-handle_call({delete, US, SIPSocket, CallID, CSeq}, _From, State) ->
-    Res = delete_session(US, SIPSocket, CallID, CSeq),
+handle_call({delete, US, CallID, CSeq}, _From, State) ->
+    Res = delete_session(US, CallID, CSeq),
     {reply, Res, State};
 handle_call(_Request, _From, State) ->
     Reply = ok,
@@ -189,8 +171,8 @@ handle_cast(_Msg, State) ->
 handle_info({write, Session}, State) ->
     write_session(Session),
     {noreply, State};
-handle_info({delete, US, SIPSocket, CallID, CSeq}, State) ->
-    delete_session(US, SIPSocket, CallID, CSeq),
+handle_info({delete, US, CallID, CSeq}, State) ->
+    delete_session(US, CallID, CSeq),
     {noreply, State};
 handle_info({timeout, TRef, US}, State) ->
     delete_expired_session(US, TRef),
@@ -208,70 +190,102 @@ code_change(_OldVsn, State, _Extra) ->
 %%%===================================================================
 %%% Internal functions
 %%%===================================================================
-register_session(US, SIPSocket, CallID, CSeq, Expires) ->
-    Session = #sip_session{us = US,
-			   bindings = [#binding{socket = SIPSocket,
-						call_id = CallID,
-						cseq = CSeq,
-						timestamp = now(),
-						expires = Expires}]},
+register_session(US, SIPSocket, CallID, CSeq, ContactsWithExpires) ->
+    Bindings = lists:map(
+		 fun({Contact, Expires}) ->
+			 #binding{socket = SIPSocket,
+				  call_id = CallID,
+				  cseq = CSeq,
+				  timestamp = now(),
+				  contact = Contact,
+				  expires = Expires}
+		 end, ContactsWithExpires),
+    Session = #sip_session{us = US, bindings = Bindings},
     call({write, Session}).
 
-unregister_session(US, SIPSocket, CallID, CSeq) ->
-    Msg = {delete, US, SIPSocket, CallID, CSeq},
+unregister_session(US, CallID, CSeq) ->
+    Msg = {delete, US, CallID, CSeq},
     call(Msg).
 
-write_session(#sip_session{us = {U, S} = US,
-			   bindings = [#binding{socket = SIPSocket,
-						call_id = CallID,
-						expires = Expires,
-						cseq = CSeq} = Binding]}) ->
-    case mnesia:dirty_read(sip_session, US) of
-	[#sip_session{bindings = Bindings}] ->
-	    case pop_previous_binding(SIPSocket, Bindings) of
-		{ok, #binding{call_id = CallID, cseq = PrevCSeq}, _}
-		  when PrevCSeq > CSeq ->
-		    {error, cseq_out_of_order};
-		{ok, #binding{tref = Tref}, Bindings1} ->
-		    erlang:cancel_timer(Tref),
-		    NewTRef = erlang:start_timer(Expires * 1000, self(), US),
-		    NewBindings = [Binding#binding{tref = NewTRef}|Bindings1],
-		    mnesia:dirty_write(
-		      #sip_session{us = US, bindings = NewBindings});
-		{error, notfound} ->
-		    MaxSessions = ejabberd_sm:get_max_user_sessions(U, S),
-		    if length(Bindings) < MaxSessions ->
-			    NewTRef = erlang:start_timer(Expires * 1000, self(), US),
-			    NewBindings = [Binding#binding{tref = NewTRef}|Bindings],
-			    mnesia:dirty_write(
-			      #sip_session{us = US, bindings = NewBindings});
-		       true ->
-			    {error, too_many_sessions}
+write_session(#sip_session{us = {U, S} = US, bindings = NewBindings}) ->
+    PrevBindings = case mnesia:dirty_read(sip_session, US) of
+		       [#sip_session{bindings = PrevBindings1}] ->
+			   PrevBindings1;
+		       [] ->
+			   []
+		   end,
+    Res = lists:foldl(
+	    fun(_, {error, _} = Err) ->
+		    Err;
+	       (#binding{call_id = CallID,
+			 expires = Expires,
+			 cseq = CSeq} = Binding, {Add, Del}) ->
+		    case find_binding(Binding, PrevBindings) of
+			{ok, #binding{call_id = CallID, cseq = PrevCSeq}}
+			  when PrevCSeq > CSeq ->
+			    {error, cseq_out_of_order};
+			{ok, PrevBinding} when Expires == 0 ->
+			    {Add, [PrevBinding|Del]};
+			{ok, _} ->
+			    {[Binding|Add], Del};
+			{error, notfound} when Expires == 0 ->
+			    {error, notfound};
+			{error, notfound} ->
+			    {[Binding|Add], Del}
 		    end
-	    end;
-	[] ->
-	    NewTRef = erlang:start_timer(Expires * 1000, self(), US),
-	    NewBindings = [Binding#binding{tref = NewTRef}],
-	    mnesia:dirty_write(#sip_session{us = US, bindings = NewBindings})
+	    end, {[], []}, NewBindings),
+    MaxSessions = ejabberd_sm:get_max_user_sessions(U, S),
+    case Res of
+	{error, Why} ->
+	    {error, Why};
+	{AddBindings, _} when length(AddBindings) > MaxSessions ->
+	    {error, too_many_sessions};
+	{AddBindings, DelBindings} ->
+	    lists:foreach(
+	      fun(#binding{tref = TRef}) ->
+		      erlang:cancel_timer(TRef)
+	      end, DelBindings),
+	    Bindings = lists:map(
+			 fun(#binding{tref = TRef,
+				      expires = Expires} = Binding) ->
+				 erlang:cancel_timer(TRef),
+				 NewTRef = erlang:start_timer(
+					     Expires * 1000, self(), US),
+				 Binding#binding{tref = NewTRef}
+			 end, AddBindings),
+	    case Bindings of
+		[] ->
+		    mnesia:dirty_delete(sip_session, US),
+		    {ok, deleted};
+		_ ->
+		    mnesia:dirty_write(
+		      #sip_session{us = US, bindings = Bindings}),
+		    {ok, updated}
+	    end
     end.
 
-delete_session(US, SIPSocket, CallID, CSeq) ->
+delete_session(US, CallID, CSeq) ->
     case mnesia:dirty_read(sip_session, US) of
 	[#sip_session{bindings = Bindings}] ->
-	    case pop_previous_binding(SIPSocket, Bindings) of
-		{ok, #binding{call_id = CallID, cseq = PrevCSeq}, _}
-		  when PrevCSeq > CSeq ->
-		    {error, cseq_out_of_order};
-		{ok, #binding{tref = TRef}, []} ->
-		    erlang:cancel_timer(TRef),
-		    mnesia:dirty_delete(sip_session, US);
-		{ok, #binding{tref = TRef}, NewBindings} ->
-		    erlang:cancel_timer(TRef),
-		    mnesia:dirty_write(sip_session,
-				       #sip_session{us = US,
-						    bindings = NewBindings});
-		{error, notfound} ->
-		    {error, notfound}
+	    case lists:all(
+		   fun(B) when B#binding.call_id == CallID,
+			       B#binding.cseq > CSeq ->
+			   false;
+		      (_) ->
+			   true
+		   end, Bindings) of
+		true ->
+		    ContactsWithExpires =
+			lists:map(
+			  fun(#binding{contact = Contact,
+				       tref = TRef}) ->
+				  erlang:cancel_timer(TRef),
+				  {Contact, 0}
+			  end, Bindings),
+		    mnesia:dirty_delete(sip_session, US),
+		    {ok, ContactsWithExpires};
+		false ->
+		    {error, cseq_out_of_order}
 	    end;
 	[] ->
 	    {error, notfound}
@@ -308,17 +322,6 @@ to_integer(Bin, Min, Max) ->
             error
     end.
 
-pop_previous_binding(#sip_socket{peer = Peer}, Bindings) ->
-    case lists:partition(
-	   fun(#binding{socket = #sip_socket{peer = Peer1}}) ->
-		   Peer1 == Peer
-	   end, Bindings) of
-	{[Binding], RestBindings} ->
-	    {ok, Binding, RestBindings};
-	_ ->
-	    {error, notfound}
-    end.
-
 call(Msg) ->
     case catch ?GEN_SERVER:call(?MODULE, Msg, ?CALL_TIMEOUT) of
 	{'EXIT', {timeout, _}} ->
@@ -329,6 +332,47 @@ call(Msg) ->
 	    Reply
     end.
 
+make_contacts_with_expires(Contacts, Expires) ->
+    lists:map(
+      fun({Name, URI, Params}) ->
+	      E1 = case to_integer(esip:get_param(<<"expires">>, Params),
+				   0, (1 bsl 32)-1) of
+		       {ok, E} -> E;
+		       _ -> Expires
+		   end,
+	      Params1 = lists:keydelete(<<"expires">>, 1, Params),
+	      {{Name, URI, Params1}, E1}
+      end, Contacts).
+
+prepare_contacts_to_send(ContactsWithExpires) ->
+    lists:map(
+      fun({{Name, URI, Params}, Expires}) ->
+	      Params1 = esip:set_param(<<"expires">>,
+				       list_to_binary(
+					 integer_to_list(Expires)),
+				       Params),
+	      {Name, URI, Params1}
+      end, ContactsWithExpires).
+
+find_binding(#binding{contact = {_, URI1, _}} = OrigBinding,
+	     [#binding{contact = {_, URI2, _}} = Binding|Bindings]) ->
+    case cmp_uri(URI1, URI2) of
+	true ->
+	    {ok, Binding};
+	false ->
+	    find_binding(OrigBinding, Bindings)
+    end;
+find_binding(_, []) ->
+    {error, notfound}.
+
+%% TODO: this is *totally* wrong.
+%% Rewrite this using URI comparison rules
+cmp_uri(#uri{user = U, host = H, port = P},
+	#uri{user = U, host = H, port = P}) ->
+    true;
+cmp_uri(_, _) ->
+    false.
+
 make_status(notfound) ->
     {404, esip:reason(404)};
 make_status(cseq_out_of_order) ->