diff --git a/examples/agent.lua b/examples/agent.lua
index 69962315..3169e324 100644
--- a/examples/agent.lua
+++ b/examples/agent.lua
@@ -1,29 +1,36 @@
 local skynet = require "skynet"
-local client
+local jsonpack = require "jsonpack"
+local netpack = require "netpack"
+local socket = require "socket"
 
 local CMD = {}
 
+local client_fd
+
+local function send_client(v)
+	socket.write(client_fd, netpack.pack(jsonpack.pack(0,v)))
+end
+
+local function response_client(session,v)
+	socket.write(client_fd, netpack.pack(jsonpack.response(session,v)))
+end
+
 skynet.register_protocol {
 	name = "client",
 	id = skynet.PTYPE_CLIENT,
-	pack = function(...) return ... end,
-	unpack = skynet.tostring,
-	dispatch = function (session, address, text)
-		-- It's client, there is no session
-		local result = skynet.call("SIMPLEDB", "text", text)
-		skynet.ret(result)
+	unpack = function (msg, sz)
+		return jsonpack.unpack(skynet.tostring(msg,sz))
+	end,
+	dispatch = function (_, _, session, args)
+		local result = skynet.call("SIMPLEDB", "lua", table.unpack(args))
+		response_client(session, result)
 	end
 }
 
 function CMD.start(gate , fd)
-	client = skynet.launch("client", fd)
-	skynet.call(gate, "lua", "forward", fd, client)
-	skynet.send(client,"text","Welcome to skynet")
-end
-
-function CMD.exit()
-	skynet.kill(client)
-	client = nil
+	client_fd = fd
+	skynet.call(gate, "lua", "forward", fd)
+	send_client "Welcome to skynet"
 end
 
 skynet.start(function()
diff --git a/examples/client.lua b/examples/client.lua
index 7bfdc8b5..b50d0039 100644
--- a/examples/client.lua
+++ b/examples/client.lua
@@ -19,16 +19,31 @@ local function dispatch()
 			break
 		end
 		for _, v in ipairs(result) do
-			print(v)
+			local session,t,str = string.match(v, "(%d+)(.)(.*)")
+			assert(t == '-' or t == '+')
+			session = tonumber(session)
+			local result = cjson.decode(str)
+			print("Response:",session, result)
 		end
 	end
 end
 
+local session = 0
+
+local function send_request(v)
+	session = session + 1
+	local str = string.format("%d+%s",session, cjson.encode(v))
+	socket.send(fd, str)
+	print("Request:", session)
+end
+
 while true do
 	dispatch()
 	local cmd = socket.readline()
 	if cmd then
-		socket.send(fd, cmd)
+		local args = {}
+		string.gsub(cmd, '[^ ]+', function(v) table.insert(args, v) end )
+		send_request(args)
 	else
 		socket.usleep(100)
 	end
diff --git a/examples/simpledb.lua b/examples/simpledb.lua
index 39d6ac06..a11fd8c5 100644
--- a/examples/simpledb.lua
+++ b/examples/simpledb.lua
@@ -4,34 +4,19 @@ local db = {}
 local command = {}
 
 function command.GET(key)
-	skynet.ret(db[key])
+	return db[key]
 end
 
 function command.SET(key, value)
 	local last = db[key]
 	db[key] = value
-	skynet.ret(last)
+	return last
 end
 
-local trace_cache = {}
-
-skynet.trace_callback(function(handle, ti)
---	print("TRACE",trace_cache[handle],ti)
-	trace_cache[handle] = nil
-end)
-
 skynet.start(function()
-	skynet.dispatch("text", function(session, address, message)
-		trace_cache[skynet.trace()] = message
-		local cmd, key , value = string.match(message, "(%w+) (%w+) ?(.*)")
-		local f = command[cmd]
-		if f then
-			f(key,value)
-		else
-			skynet.ret("Invalid command : "..message)
-		end
+	skynet.dispatch("lua", function(session, address, cmd, ...)
+		local f = command[string.upper(cmd)]
+		skynet.ret(skynet.pack(f(...)))
 	end)
 	skynet.register "SIMPLEDB"
 end)
-
-
diff --git a/examples/watchdog.lua b/examples/watchdog.lua
index a6d5339a..8ead2253 100644
--- a/examples/watchdog.lua
+++ b/examples/watchdog.lua
@@ -1,4 +1,5 @@
 local skynet = require "skynet"
+local netpack = require "netpack"
 
 local CMD = {}
 local SOCKET = {}
@@ -13,7 +14,6 @@ end
 local function close_agent(fd)
 	local a = agent[fd]
 	if a then
-		skynet.call(a, "lua", "exit")
 		skynet.kill(a)
 		agent[fd] = nil
 	end
@@ -29,6 +29,9 @@ function SOCKET.error(fd, msg)
 	close_agent(fd)
 end
 
+function SOCKET.data(fd, msg)
+end
+
 function CMD.start(conf)
 	skynet.call(gate, "lua", "open" , conf)
 end
diff --git a/lualib/jsonpack.lua b/lualib/jsonpack.lua
new file mode 100644
index 00000000..b1da80cd
--- /dev/null
+++ b/lualib/jsonpack.lua
@@ -0,0 +1,19 @@
+local cjson = require "cjson"
+
+local jsonpack = {}
+
+function jsonpack.pack(session, v)
+	return string.format("%d+%s", session, cjson.encode(v))
+end
+
+function jsonpack.response(session, v)
+	return string.format("%d-%s",session, cjson.encode(v))
+end
+
+function jsonpack.unpack(msg)
+	local session,t,str = string.match(msg, "(%d+)(.)(.*)")
+	assert(t == '+')
+	return tonumber(session) , cjson.decode(str)
+end
+
+return jsonpack
\ No newline at end of file
diff --git a/service/gate.lua b/service/gate.lua
index 86d00209..1f3aea0b 100644
--- a/service/gate.lua
+++ b/service/gate.lua
@@ -8,10 +8,9 @@ local watchdog
 local maxclient
 local client_number = 0
 local CMD = setmetatable({}, { __gc = function() netpack.clear(queue) end })
-local forwarding_address = {}
-local forwarding_client = {}
-local forwarding_map = {}
-local openning = {}
+
+local connection = {}	-- fd -> connection : { fd , client, agent , ip, mode }
+local forwarding = {}	-- agent -> connection
 
 function CMD.open( source , conf )
 	assert(not socket)
@@ -29,72 +28,70 @@ function CMD.close()
 	socket = nil
 end
 
-local function unforward_fd(fd)
-	local address = forwarding_address[fd]
-	if address then
-		local client = forwarding_client[fd]
-		local fm = forwarding_map[address]
-		if type(fm) == "table" then
-			fm[address] = nil
-			if next(fm) == nil then
-				forwarding_map[address] = nil
-			end
-		else
-			forwarding_map[address] = nil
-		end
-		forwarding_address[fd] = nil
-		forwarding_client[fd] = nil
-		return address, client
+local function unforward(c)
+	if c.agent then
+		forwarding[c.agent] = nil
+		c.agent = nil
+		c.client = nil
 	end
 end
 
+local function start(c)
+	if not c.mode then
+		c.mode = "open"
+		socketdriver.start(c.fd)
+	end
+end
 
 function CMD.forward(source, fd, client, address)
-	local addr = address or source
-	if not unforward_fd(fd) then
-		socketdriver.start(fd)
-	end
+	local c = assert(connection[fd])
+	unforward(c)
+	start(c)
 
-	forwarding_address[fd] = addr
-	forwarding_client[fd] = client or 0
-	local fm = forwarding_map[addr]
-	if fm then
-		if type(fm) == "table" then
-			fm[addr] = true
-		else
-			fm[addr] = { [fm] = true, [addr] = true }
-		end
-	else
-		forwarding_map[addr] = fd
-	end
+	c.client = client or 0
+	c.agent = address or source
+
+	forwarding[c.agent] = c
+end
+
+function CMD.accept(source, fd)
+	local c = assert(connection[fd])
+	unforward(c)
+	start(c)
 end
 
 function CMD.kick(source, fd)
-	if not fd then
-		fd = forwarding_map[source]
-		if type(fd) == "table" then
-			for k in pairs(fd) do
-				socketdriver.close(k)
-			end
-			return
-		end
+	local c
+	if fd then
+		c = connection[fd]
+	else
+		c = forwarding[source]
+	end
+
+	assert(c)
+
+	if c.mode ~= "close" then
+		c.mode = "close"
+		socketdriver.close(c.fd)
 	end
-	socketdriver.close(fd)
 end
 
 local MSG = {}
 
 function MSG.data(fd, msg, sz)
-	local address = forwarding_address[fd]
-	local client = forwarding_client[fd]
-	skynet.redirect(address, client, "client", 0, msg, sz)
+	-- recv a package, forward it
+	local c = connection[fd]
+	local agent = c.agent
+	if agent then
+		skynet.redirect(agent, c.client, "client", 0, msg, sz)
+	else
+		skynet.send(watchdog, "lua", "socket", "data", netpack.tostring(msg, sz))
+	end
 end
 
 function MSG.more()
 	for fd, msg, sz in netpack.pop, queue do
-		local address = forwarding_address[fd]
-		local client = forwarding_client[fd]
-		skynet.redirect(address, client, "client", 0, msg, sz)
+		MSG.data(fd, msg, sz)
 	end
 end
 
@@ -103,15 +100,20 @@ function MSG.open(fd, msg)
 		socketdriver.close(fd)
 		return
 	end
-	openning[fd] = true
+	local c = {
+		fd = fd,
+		ip = msg,
+	}
+	connection[fd] = c
 	client_number = client_number + 1
 	skynet.send(watchdog, "lua", "socket", "open", fd, msg)
 end
 
-local function close_fd(fd)
-	local address, client = unforward_fd(fd)
-	if openning[fd] then
-		openning[fd] = nil
+local function close_fd(fd, message)
+	local c = connection[fd]
+	if c then
+		unforward(c)
+		connection[fd] = nil
 		client_number = client_number - 1
 	end
 end
@@ -123,7 +125,7 @@ end
 
 function MSG.error(fd, msg)
 	close_fd(fd)
-	skynet.send(watchdog, "lua", "socket", "error", fd)
+	skynet.send(watchdog, "lua", "socket", "error", fd, msg)
 end
 
 skynet.register_protocol {