[SR-Users] kamailio with kannel

hello dears , i'm trying to use "http_client" module to post SMS from kamailio to kannel using the following configuration : ....... modparam("http_client", "httpcon", "kannel=>http://username:password@127.0.0.1:443") .......... ......... http_connect("kannel","cgi-bin/sendsms?user=username&pass=password&charset=utf-16&coding=2&from=$avp(from)&to=$avp(to)&text=$(avp(text){s.escape.user})","$var(result)"); ....... And this test success for English characters & phrases, but when i'm trying to send Arabic or Chinese characters it only success if the content of the SMS only has one word. in other-word i mean when i'm trying to send more than one Arabic word with a space between each word it reply with HTTP error code 400. so do you have any ideas about this problem ??