Cisco 7925G Administration Guide - Page 41

Chapter 2 Overview of the VoIP Wireless Network Components of the VoIP Wireless Network Table 2-4 Supported Networking Protocols (continued) Networking Protocol Purpose Usage Notes TCP Connection-oriented transport Cisco Unified IP Phones use TCP to protocol. connect to Cisco Unified Communications Manager and to access XML services. TFTP Method for transferring files over the network. On the Cisco Unified IP Phone, TFTP enables you to obtain a configuration file specific to the phone type. You must have a TFTP server in your network that the DHCP server automatically identifies. If more than one TFTP server is running in your network, you must manually assign a TFTP server to each phone. TLS TLS is a standard protocol for When security is implemented, Cisco securing and authenticating Unified IP Phones use the TLS communications. protocol when securely registering with Cisco Unified Communications Manager. User Datagram Protocol Connectionless messaging protocol Cisco Unified IP Phones receive and (UDP) for delivery of data packets. process UDP messages. RTP voice traffic runs over UDP. Related Topics • Understanding the Phone Startup Process, page 3-17 • Components of the VoIP Wireless Network, page 2-9 • Configuring DHCP Settings, page 5-6 Interacting with Cisco Unified Wireless APs Wireless IP phones use the same APs as wireless data devices. However, voice traffic over a WLAN requires different equipment configurations and layouts than a WLAN that is used exclusively for data traffic. Data transmission can tolerate a higher level of RF noise, packet loss, and channel contention than voice transmission. Packet loss during voice transmission can cause choppy or broken audio and make the phone call inaudible. Wireless IP Phones users are mobile and often roam across a campus or between floors in a building while connected to a call. In contrast, data users remain in one place or occasionally move to another location. The ability to roam while maintaining a call is one of the advantages of wireless voice so RF coverage needs to include stairwells, elevators, quiet corners outside conference rooms, and passage ways. To ensure good voice quality and optimal RF signal coverage, you must perform a site survey. The site survey will determine settings suitable to wireless voice and assist in the design and layout of the WLAN; for example AP placement, power levels, and channel assignments. After deploying and using wireless voice, you should continue to perform post installation site surveys. When you add a group of new users, install more equipment, or stack large amounts of inventory, you are changing the wireless environment. A post installation survey will verify that the AP coverage is still adequate for optimal voice communications. See the "Site Survey Verification" section on page 2-22 for more information. OL-15984-01 Cisco Unified Wireless IP Phone 7925G Administration Guide for Cisco Unified Communications Manager 7.0(1) 2-11