 phones are the primary end- points; and the primary applications are voice devices. Figure 2-1 shows how the tradi- tional telephony protocols, endpoints, and applications are distributed. With IP communications, a few numbers of distinct protocols still exist; however, to date these protocols are still in the early stage of development, and their implementation varies by vendor. This is most likely a short-term issue. Long term, the expectation is that the industry will resolve to a use a few well-defined protocols. In the area of endpoints, the trend toward diversity goes beyond just protocols. The com- munications methods between the endpoints expand with IP communications. These methods for communicating between endpoints over IP include voice, video, chat, pho- tos, and even the capability to provide remote haptic feedback. Finally, the true value of IP communications is in the applications. The number, value, and variety of applications in IP communications explode. Figure 2-2 shows how IP communication is distributed. Chapter 2: Trends in IP Telephony 13 The number of protocols in traditional TDM Protocols telephony is consistent. (SS7, ISDN, and CAS dominate the connection methods.) The variety of the number of endpoints is Endpoints consistent. Many types of phones can be purchased; however, they share the exact same interface. The applications are limited. The features need Applications to be created by the SP. The last major feature is Caller ID. Figure 2-1 Historical Distribution of Telephony The number of protocols in IP communications gets smaller with Protocols focus on SIP. The variety of the number of endpoints explodes with Endpoints more and more customization, either soft or hard endpoints. The number of applications is limitless in IP communications Applications because they can be implemented outside of the SP. Figure 2-2 Distribution of IP Communication Enterprise IP Communications Endpoints Several accepted definitions for enterprise scale deployments exist, ranging from 10 to millions of