Great! could you clarify, "Recently, voice over ip (voip) toll-bypass has been prevented by ISP=92s= =20 that block out voice over ip ports that are being used to carry voice=20 over ip calls thru their network. Vonage has sued the local ISPs have=20 won." -
Does that mean ISP's are allowed to block VoIP calls? Is that by port blocking or some other means?
In the U.S., the answer would be no. One ISP that did do this was "fined" $15,000 by the FCC.
Generally speaking, it is an ISP's interest NOT to block calls, the rationale being that the more utility (value) the customer finds in the IP conectivity being provided, the more they are willing to pay. BUT... When when the ISP is also in the business of delivering traditional telephone service, you see this kind of thing attempted in order to preserve what are often monopoly positions on that service. In many cases, the measures taken are far more serious that merely blocking ports. For example, recent reports have stated that Mexican authorities have arrested two Vonage employees for transporting telephone traffic out of Mexico without the proper "concession" (failing to grease the right palms). The U.A.E. also plays serious hard-ball with those who try to circumvent their monopoly, jailing would be competitors.