Cisco SPA2102-SF Administration Guide - Page 17

194487 Introducing Cisco Small Business Analog Telephone Adapters Comparison of ATA Devices 1 Figure 2 ATA Deployment with Onsite Call Control Optional On-Site Call Control (SPA9000 or Legacy PBX) Telephone/ fax V Linksys ATA Ethernet Broadband Broadband CPE (DSL, cable, fixed wireless) Layer 3 IP infrastructure Voice gateway V PSTN SIP proxy This chapter introduces the functionality of the ATA devices and describes the features that are available. Refer to the following topics: • "Comparison of ATA Devices," on page 17 • "ATA Connectivity Requirements," on page 20 • "ATA Software Features," on page 26 Comparison of ATA Devices Each ATA device is an intelligent low-density Voice over IP (VoIP) gateway that enables carrier-class residential and business IP Telephony services delivered over broadband or high-speed Internet connections. An ATA device maintains the state of each call it terminates and makes the proper reaction to user input events (such as on/off hook or hook flash). The ATA devices use the Session Initiation Protocol (SIP) open standard so there is little or no involvement by a "middle-man" server or media gateway controller. SIP allows interoperation with all ITSPs that support SIP. The ATA Models table summarizes the ports and features provided by the ATA devices described in this document. Cisco Small Business ATA Administration Guide 17