Voice over IP refers to telephony technology that transmits voice communications over a network using IP standards. Cisco AVVID (Architecture for Voice, Video and Integrated Data) provides the infrastructure and feature set for creating a single converged network that can handle voice, video, and data traffic simultaneously. It provides this capability while maintaining a high level of network availability, Quality of Service (QoS), and security. Important advantages of IP communications solutions enabled by Cisco's AVVID architecture include:  A flexible, interoperable migration strategy that allows you to choose IP Communications  

     solutions that meet your current needs, while providing a smooth path for accelerating IP deployment

     QoS mechanisms that help ensure high voice quality through tight control of delay, loss and jitter

     Network management products that provide network administration, operations, troubleshooting, configuring, fault monitoring and element management

The architecture of the Cisco IP Telephony solution consists of communications endpoints, call-processing agents, and IP telephony applications.

A communications endpoint is a user instrument, either a desk phone or a software phone application that runs on a PC. In the IP environment, each phone has an Ethernet connection. IP phones have all of the functions that a telephone provides. They can also have additional features such as the ability to access Websites or to run productivity-enhancing applications.

Unlike traditional PBX systems, in a Cisco IP Telephony network you can perform virtually instantaneous moves, adds and changes. You simply take the IP phone to your new location, plug it into the Ethernet jack, and the phone registers itself with Cisco CallManager. All user privileges and settings are automatically re-established, eliminating the cost and delay of sending technicians to wiring closets. Another helpful feature is extension mobility, which allows you to log into any Cisco IP phones and receive your own phone number and privilege.

The call-processing agent is the heart of the Cisco IP Telephony system. To meet your organizational needs you can choose to deploy a centralized call-processing model, a decentralized model, or a combination of both. In a centralized deployment, Cisco CallManager extends enterprise telephony features and capabilities to packet telephony network devices such as IP phones, media processing devices, voice over IP (VoIP) gateways, and multimedia applications throughout the network. Cisco CallManager enables additional voice, video, and data services such as unified messaging, multimedia conferencing, collaborative customer interaction networks, and interactive multimedia response systems.

When a central Cisco CallManager cluster also handles call processing for users at distributed sites, administrators can help ensure continuous phone service using Cisco Survivable Remote Site Telephony (SRST), a Cisco IOS Software image for Cisco routers. If a WAN link fails, Cisco SRST in the router provides basic Cisco CallManager capabilities until the link is restored.

For small offices or loosely coupled small enterprise branch locations that do not require the full, enterprise-class feature set offered by Cisco CallManager, Cisco CallManager Express offers a cost-effective solution that meets the requirements of sites with fewer than 100 employees. Since Cisco CallManager Express is embedded in the Cisco IOS Software running on a Cisco multiservice access router, smaller offices are able to simply and easily deploy a converged voice and data solution.

The Cisco Unity application delivers powerful unified messaging including e-mail, intelligent voice messaging, and faxes managed from a single inbox.

The Cisco Unity solution integrates advanced convergence-based communications services with everyday desktop applications such as Microsoft Outlook. With Cisco Unity Unified Messaging, you can listen to e-mail over the telephone, check voice messages from the Internet, and forward faxes to your current location. Cisco Unity Voice Messaging offers automated attendant features that include intelligent routing and customizable call screening and message notification options.

The Cisco Unity solution supports both Cisco CallManager and leading PBX systems to help your business transition to IP telephony at your own pace and protect your existing infrastructure investments. The solution also offers several networking modules that enable advanced message interchange with popular voice-mail systems. While you are migrating to the Cisco Unity solution, these modules help to ensure a smooth transition by giving you the ability to exchange messages with internal system subscribers who reside on a different messaging system.

The Cisco Personal Assistant telephony application allows your users to manage how and where they want to be reached by offering features such as rules-based call routing, simplified contact management, and speech recognition. With Cisco Personal Assistant, users can customize call screening and forwarding features, routing calls based on time of day, who the caller is, and calendar appointments. All of this requires no assistance from your IT department. Streamlining outbound communications can be done with speech recognition access to name dial contacts in the corporate directory or Microsoft Outlook contact list. Speech commands are also used to set up ad hoc conference calls, initiate “follow me” call routing, and respond to voice-mail messages.

Cisco Unity Express offers local voice-mail and automated attendant capabilities for IP phone users connected to either Cisco CallManager or Cisco CallManager Express in a small or branch office location. Cisco Unity Express is fully integrated into the Cisco access router either on a network module or an advanced integration module (AIM). Cisco Unity Express serves up to 100 subscribers, with features intended for the small business or branch office.

FlipNet can provide a Cisco Certified Internetwork Expert (CCIE) or Cisco Certified Network Professional (CCNP) to help you deploy Cisco VoIP technology. Progent can evaluate your existing network and Internet access infrastructure to determine whether your environment is optimized to support VoIP, help you select and deploy Cisco hardware and software appropriate for your current situation and future growth plans, and business objectives, and integrate your VoIP solution with technology from other vendors.