mat@cisco.com (Michael Thomas) writes: > Voice challenges this assumption to a very large > degree. In fact, I not only want access to 99.99% > of the other nodes on the net willing to speak RTP ... actually i think you probably don't, or rather, won't. telemarketing by robot is illegal in some places but is widely used to detect fax machines or voice-answered lines for later use by other robots or by humans. one of the cost components for this kind of activity today is a room full of CTI hardware and a DS1 (or better) and a willingness to buy blocks of long distance minutes. assuming VoIP takes off, the costs of robotic telemarketing are going to go way way down. in particular, it may become popular to sweep the E164.ARPA address space looking for endpoints, then sweep the resulting RTP endpoints looking for live reachable instruments like humans and fax machines. it's safe to say that the same people who call you at home during dinner to sell you chemicals for your septic tank are going to team up with the same people who send you spam or who do "e-mail appending" or who spam your fax machine with vacation offers... ...and that your RTP instrument will have to be one of the most violently over-firewalled devices on your network in order to remain useful for its intended (by you that is) purpose. maybe i should get back into the blackhole business, but for VoIP this time, since it'll be a HUUUUGE market. -- Paul Vixie