el Call Manager Communications application Standard On The Phone that includes the following: (Connected 00:52 Telephony features Meigy Schmidt 1002 Instant messaging Hold Transfer 00 Hangup Hide Preview Employee directories with Chicago Mathe presence indicators Meigy Schet Video communications Smith Unified messaging with e-mail and voicemail in the same inbox Pedro fe Paris Pascal Due conferencing and collaboration with desktop files sharing Contacts Voice Microsoft Outlook integration with presence indicators Figure 2-9 Video conferencing and other capabilities in Unified Communications (UC). (Courtesy ShoreTel) In the past, I would have to set aside three days to fly to Europe simply for the purposes of conducting a single meeting that I couldn't conduct over the phone, because it required mine and my client's visual aids in order to effectively communicate the subject matter. Now, I'm able to conduct these meetings without the additional travel time, as if the per- son were sitting right next to me, saving me money and time-two of my favorite things! These desktop video capabilities are now integrated in UC services in many tele- phone systems. Session Initiation Protocol in UC Session Initiation Protocol (SIP) is a signaling standard made up of a number of pro- tocols that define a uniform way to connect IP telephone systems to data networks, set up phone calls, audio and video conferences, and configure features on phones SO that telephones from different manufacturers interact as designed. SIP is also important in UC because it recognizes signals from devices, indicating their state. It can detect whether a user is on a telephone call or whether she is logged in to e-mail. SIP uses these presence indicators to tie these applications together. A presence indicator informs a sender as to whether the person she wishes to contact is available, busy, or not available, before she sends an e-mail or instant message. Value-Added Applications for Telephone Systems Group Video Conferencing in Private and Public Co