Asterisk & RTC Client API

I am having a problem with asterisk and RTC Client API, my scenario is as follows

RTC clients registered with Asterisk

When client A calls client B everythings goes fine except that Client A can hear Client B but Client B cant hear Client A for exactly 8 seconds after 8 seconds both parties can hear each other.

I think its a RTC Client API problem because this happens only when there RTC clients are involve in it, If I use SJPhone or any other SIP phone it doenst happen but still posting this Question here to hope that someone may experienced this problem and resolved it