Ryan was cited for an incident which occurred during the second half of last Saturday's Test match between Ireland and Samoa at the Aviva Stadium.
Having considered all of the evidence, the disciplinary committee, which also comprised Achille Reali (Italy) and Simon Thomas (Wales), found that Ryan was guilty of foul play and imposed a suspension of three weeks from November 15 until midnight on Sunday, December 5.
The committee, having listened to submissions from Ryan, his legal representative and Paul McNaughton, the Ireland team manager, and viewed the video evidence, found that the incident merited a mid-range entry point in the IRB list of sanctions which they then reduced on account of the player's exemplary disciplinary record and good conduct at the hearing.
Ryan has the right of appeal. As things stand, he will be unavailable for Ireland's upcoming Tests against New Zealand and Argentina and Munster's Magners League matches against the Scarlets, the Newport Gwent Dragons and the Cardiff Blues.