Simply make sure that the client who has audio/video MUST create offer; and other client should create answer. Then it will be oneway streaming; and it will work!
userWhoHasMedia.createOffer(sdp_sucess_callback, sdp_failure_callback, sdp_constraints);
userWhoDontHavemedia.createAnswer(sdp_sucess_callback, sdp_failure_callback, sdp_constraints);
Also, if you want, you can set "OfferToReceiveAudio
" and "offerToReceiveVideo
" to false for client who doesn't captures media. Though, it is useless in your case, because non-Media client is receiver.