First SABM This topic has 1 reply, 1 voice, and was last updated 13 years, 12 months ago by pix. Viewing 2 posts - 1 through 2 (of 2 total) Author Posts 13th November 2010 at 12:01 #64963 USerGuest Hi What is First SABM message which used in Handover and Call Setup flows? 13th November 2010 at 21:00 #64964 pixGuest hi sabm is just the ack of the UA message. UA + SABM = handshake of the LapDm. After those two messages, the layer 2 (lapdm) is established. for more info, google SABM + LapDm regards pix Author Posts Viewing 2 posts - 1 through 2 (of 2 total) The forum ‘Telecom Design’ is closed to new topics and replies.