what is the interface X.21,V.2 This topic has 0 replies, 1 voice, and was last updated 19 years, 6 months ago by sarahl. Viewing 1 post (of 1 total) Author Posts 10th May 2005 at 16:24 #29460 sarahlGuest and E&M? i can’t find these concepts from google thanks Author Posts Viewing 1 post (of 1 total) The forum ‘Voice over IP’ is closed to new topics and replies.