Station Devices

This chapter describes the interaction between CallManager and station devices, including station functionality and the protocols they use to communicate with Cisco CallManager. The station protocol is part of the Protocol/Aggregation Layer within CallManager. CallManager contains several signaling layers, each of which has distinct functions. For example, the Call Control Layer handles all of the call signaling that controls call setup, teardown, and call routing; and the Protocol/Aggregation Layer handles all protocol-specific signaling required for specific devices.

This chapter discusses the following topics:

• Definition of Station Devices Introduces the station device in the context of CallManager
• Overview of Station Devices Supported by CallManager Differentiates users from stations and categorizes the station devices by protocol
• Station Device Features Introduces the feature content offered to users of the station devices
• SCCP Station Devices Describes the functionality of the devices that support the Skinny Client Control Protocol (SCCP) and provides an overview of the protocol that supports the devices
• Cisco VT Advantage Describes the functionality of the PC-based Cisco VT Advantage that provides video functionality for Cisco IP Phones
• Computer Telephony Interface (CTI) Devices Describes the interface support for devices that connect to CallManager through CTI, including CTI route points, CTI ports, and CTI-monitored/controlled IP phones
• IP Phone Registration and Security Provide descriptions of how station devices use TFTP and ways to secure IP phones
• H.323 Endpoint Devices Describes the H.323 endpoints and provides an overview of CallManager's H.323 protocol support

Appendix C, "Protocol Details," provides detailed information for signaling protocols such as SCCP, and application protocols like JTAPI and XML. After reviewing this chapter, refer to Appendix C for additional, related information.

Figure 3-1 shows the block structure of CallManager. The darker shading in Figure 3-1 highlights the software layers and blocks within CallManager that this chapter describes in detail. Other blocks are highlighted with lighter shading. They are part of the station signaling path, but are given lighter coverage.

Figure 3-1. CallManager Block Structure Diagram

The software in the Media Control Layer handles all media connections CallManager makes between devices. Whereas the Call Control Layer sets up all of the signaling connections between call endpoints and CallManager, the Media Control Layer directs the devices to establish streaming connections. The Media Control Layer can insert other media processing devices into a call and create appropriate streaming connections to those devices without the Call Control Layer knowing about them.

The blocks in the Protocol/Aggregation Layer control the media processing devices. They provide the device interface and handle all communication between the devices and CallManager.