Cisco Systems manual Cisco 7920 IP Phone Overview, Wlan Overview, Components Used, Conventions

Page 3

∙AVVID design guides and administration.

Components Used

The information in this document is based on the software and hardware versions below:

∙The Cisco 7920 IP Phone.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, see the Cisco Technical Tips Conventions.

Cisco 7920 IP Phone Overview

The Cisco 7920 IP Phone extends the AVVID family of IP phones from 10/100 Ethernet to 802.11b WLANs. The Cisco 7920 provides a multi−line appearance with functionality similar to existing Cisco 79xx IP Phones. In addition, the Cisco 7920 provides enhanced WLAN security and Quality of Service (QoS) for operation in 802.11b networks. Future enhancements to the Cisco 7920 will add support for XML−based data access and services, as well as Universal Serial Bus (USB) connectivity for additional data services.

WLAN Overview

802.11b WLAN networks allow multiple devices to transmit data, voice, and video at data rates up to 11Mb. While WLAN networks allow similar types of traffic to be transmitted over them, it does have certain characteristics that differ from wired networks:

∙WLANs operate as a shared medium, which means that communication on the WLAN is half−duplex and that all devices within a single WLAN share the 11Mb.

∙WLAN bandwidth varies based on the distance that a WLAN client is from a WLAN Access Point (AP). The farther the distance, the lower the data rates that traffic is supported.

∙Since all WLAN traffic is seen by all other WLAN devices (within range), additional security considerations need to be taken to ensure that traffic is not captured or manipulated by intruders.

RF Overview ￿ Site Surveys and Design Recommendations

Before getting started with any WLAN deployment, the first activity that every network administrator should undertake is a complete site survey of the environment where the WLAN devices are deployed. The site survey should be performed to understand the number of APs required to provide Radio Frequency (RF) coverage. It should take into consideration which types of antennas provide the best coverage, as well as where sources of RF interference exist.

An important factor to keep in mind is that rarely do two physical environments have the same RF characteristics. Because of this, the sections of this document that are RF specific are generalized. Network administrators may need to adjust those parameters to their specific RF environment and requirements.

While you may have already performed RF site surveys for an initial WLAN deployment, it is important to

Cisco − Wireless IPT Design Guide for the Cisco 7920 IP Phone

Page 2 Page 4
Image 3
Page 2 Page 4
Contents Table of Contents Introduction PrerequisitesRequirements Components Used Cisco 7920 IP Phone OverviewWlan Overview RF Overview Site Surveys and Design RecommendationsRssi VoIP QoS∙ Delay Variation Jitter Not to exceed 30ms Security for the Cisco 7920 and Wlan Networks Network Sizing Number of 802.11b Devices per APNumber of 802.11b IP Phones per AP Page Numbers of 802.11b Phones per Layer 2 Subnet or Vlan Understanding Roaming Terminology Understanding Layer 2 and Layer 3 RoamingLayer 2 Roaming Page Layer 3 Roaming VLANs Wlan QoS for VoIP Page Page Page Interconnecting WLANs to Cisco Campus Infrastructure Connecting APs to the Catalyst 3550 SMI or EMI Connecting APs to the Catalyst 2950 SI Connecting APs to the Catalyst 2950 EICaveats and Limitations Call Admission Control Designing Around the Lack of Layer 3 RoamingOther Caveats and Limitations Related Information

7920 IP specifications

The Cisco Systems 7920 IP phone represents a significant advancement in wireless communication technology, designed specifically for enterprises that require mobility and efficiency in their communication systems. This versatile device integrates seamlessly into a Cisco IP telephony network, allowing users to maintain connectivity while on the move, which is essential in fast-paced business environments.

One of the key features of the Cisco 7920 is its robust wireless capabilities. Operating on the IEEE 802.11b/g Wi-Fi standards, it provides a reliable connection to corporate networks, ensuring that users can access voice, data, and video services without being tethered to a desk. The phone supports dynamic call handling and features a responsive LCD display that enhances user interaction, making it easier to navigate menus and manage calls.

The Cisco 7920 also offers exceptional sound quality, thanks to its advanced audio technology. With Wideband audio support, users can experience clarity in conversations, which is particularly important in environments where clear communication is vital. The phone is equipped with noise-canceling capabilities that reduce background noise, allowing users to focus on their conversations without distractions.

Security is another critical aspect of the Cisco 7920. The device supports several security protocols, including WPA and WPA2, ensuring that all communications are encrypted and secure. This is crucial for organizations that handle sensitive information and need to comply with industry regulations.

Additionally, the Cisco 7920 features an extended battery life, enabling users to make calls throughout the day without frequent recharging. Its lightweight design and ergonomic build make it comfortable to use for extended periods.

In terms of integration, the Cisco 7920 IP phone is compatible with various Cisco Unified Communications Manager software versions, allowing for easy configuration and management within existing network infrastructures. Its support for multiple languages also makes it a suitable choice for international organizations, accommodating diverse user groups.

Overall, the Cisco Systems 7920 IP phone combines the necessary features, technologies, and characteristics to meet the demands of modern enterprise communication. Its blend of wireless capability, superior audio quality, security measures, and integration versatility makes it an excellent choice for organizations seeking efficient and reliable communication solutions.
Top Page Image Contents