http://articledirectorystore.com/communications/voip/is-sip-an-alternative-to-isdn/ Sun, 29 Nov 2009 13:44:42 +0000 http://backend.userland.com/rss092 en The creation of virtual phone lines between your PBX and the public network is accomplished by a new technology called SIP.(Session Initiation Protocol).The following article attempts to answer the question :-Is SIP a cost effective solution to ISDN? Telephone calls can then be made over your internet connection with the subsequent ... http://articledirectorystore.com/communications/voip/is-sip-an-alternative-to-isdn/