Thank Klaus, I've try with t_suspend() and t_continue() as your guide, *#Failure route to react with negative messages failure_route[1] { if (t_check_status("5[0-9][2-9]")) { if(t_suspend()) { xlog("proceesing suspended in trasaction [$T(id_index):$T(id_label)]\n"); xlog("before sleep \n"); } if(async_sleep("20")) xlog("After sleep 20s \n"); if(t_continue('1','1','MYROUTE')) xlog("Continuation successfully \n"); exit; };* And i found that t_suspend() and async_sleep() runnung ok but t_continue() seems not running. I read about TMX module and TMX module Pseudo-Variables but still can not figure out it :( Secondly, in case of t_continue() runs successfully , please tell me how to let Kamailio resend the INVITE message to client B (before the t_continue(), i think so ) - while client B is waking up ? Which functions and modules that i need to do this? Thanks. ----------------------------------------------------------------- Hi! You have to use a failure route (http://kamailio.org/docs/modules/3.3.x/modules/tm.html#t_on_failure). In the failure route check if the reply code is 404 and if yes, trigger the APNS logic and then put the call e.g. on a stack and resume e.g. every second and ofrward to the "SIP server" again to see if the client is registered meanwhile. For the asynchronous processing take a look at these functions: t_suspend(),t_resume()[1]. For example you can call t_resume in a timer route every second. For the timer route, to know which transactions are currently suspended and are waiting for further processing, you could put the transaction identifiers in a message-queue [2] and read the queue from the timer route. regards Klaus [1] http://kamailio.org/docs/modules/3.3.x/modules_k/tmx.html#id2535968 [2] http://kamailio.org/docs/modules/3.3.x/modules/mqueue.html On 24.07.2012 06:02, Duong Manh Truong wrote: