Hello. I try to do parallel  fork calls to endpoints that have same username and different destination URI. Logic of my script:
checking location table for rows with needed account

get info from contact at loop

for every step

check technology (sip or ws)
append_branch with existing destination for this account
rewrite packet with rtpengine to needed technology

forward packets via t_relay

sql_query("ca", "select contact from location where username='$tU'", "ra");

xlog("rows: $dbr(ra=>rows) cols: $dbr(ra=>cols)\n");

if($dbr(ra=>rows)>0){

$var(i)=0;

while($var(i)<$dbr(ra=>rows)){

xlog("L_INFO","SQL query return contact {$dbr(ra=>[$var(i),0])} for {$tU} at step {$var(i)}\n");

if ($dbr(ra=>[$var(i),0])=~"transport=ws"){

xlog("L_INFO", "This is a Websocket call to endpoint");

sql_pvquery("ca", "select received from location where contact='$dbr(ra=>[$var(i),0])'","$var(recieved)");

xlog("L_INFO","SQL query return recieved {$var(recieved)} for {$tU}\n");

$du=$var(recieved);

xlog("L_INFO", "Request going FROM ASTERISK to WS. Destination is {$du}\n");

xlog("L_INFO","Websocket Destination URI is {$var(recieved)} for {$tU}\n");

rtpproxy_manage("froc+SP");

t_on_reply("REPLY_FROM_WS");

append_branch("sip:$tU@$du");

$var(i) = $var(i) + 1;

}

else

{

xlog("L_INFO", "This is a classic UDP call to endpoint");

$du="sip:"+$(dbr(ra=>[$var(i),0]){s.select,1,@});

xlog("L_INFO","Classic Destination URI is {$dbr(ra=>[$var(i),0])} for {$tU}\n");

rtpproxy_manage("co");

t_on_reply("MANAGE_CLASSIC_REPLY");

append_branch("sip:$tU@$du");

$var(i) = $var(i) + 1;

}

#append_branch("sip:$tU@$du");

}

}

return 1;

So it customised schema of standart example 

  seturi("sip:a@example.com");

  append_branch("sip:b@example.com");

  append_branch("sip:c@example.com");

  append_branch("sip:d@example.com");

  t_relay();

At my test I have 2 endpoints with WS and UDP phones (at fist step ir WS and 2 step it UDP). when I do these steps (at my script) I see packet at TCP dump and saw that sended only one packet to UDP but body of packet is WS. Then I saw log of kamailio. I see that at second step packet changed body to WS body (so strange because other steps before and after goes for UDP (as at logic of script))

What I need to do for send parallel INVITES to multiple endpoints correctly? Thanks