able operators are ready to offer VoIP and commercial services on a large scale that they will begin using DOCSIS 2.0. Although most operators will build it into their hardware, it will be the services-from IP voice to multi- media gaming-that will drive MSOs' decisions to implement DOCSIS 2.0. Cable TV Networks DOCSIS 3.0 DOCSIS 3.0, currently under development, will increase the capacity up to a minimum of 160Mbps downstream to customers and a minimum 120Mbps upstream. In DOCSIS 3.0, several downstream and several upstream chan- nels can be bonded together to multiply the bandwidth delivered to each customer. DOCSIS 3.0 will most likely require a new chip at the modem and at the CMTS. However, DOCSIS 3.0 will be worth the effort because it will give operators enough bandwidth to offer a wider range of IP-based offerings, including entertain- ment-quality media services. (Table 12.3 compares the amount of bandwidth each DOCSIS version provides.) DOCSIS 3.0 adds entertainment video on top of the services supported by DOCSIS 2.0 and 2.x, and it also adds support for IP set-top boxes to the list of equipment supported by the earlier DOCSIS versions. DOCSIS DSG The cable industry is applying DOCSIS to many services and applications beyond just Internet access, including new applications to control the communications pathway for digital set-top boxes and to monitor the health of the cable plant, including power supplies and amplifiers. DOCSIS Set-top Gateway (DSG) is an extension to the DOCSIS standards that gives operators a standard method to deliver out-of-band data, such as channel lineups and program guides, and more advanced streaming applications via a DOCSIS channel to the digital cable set-top box. The DSG network consists of three main elements: the DSG gateway, which is responsible for generating the stream of out-of-band data; the DSG agent, which is the same as a CMTS and is responsible for forwarding the out-of-band data as well as publishing the out-of-band directory; and the set-top box. The set-top b