By the year 2000, voicemail had become a ubiquitous feature on phone systems serving companies, cellular and residential subscribers. Cellular and residential voicemail continue today in their previous form, primarily simple telephone answering. Email became the prevalent messaging system, email servers and software became quite reliable, and virtually all office workers were equipped with multimedia desktop PCs.

Instant messaging in voice: The next development in messaging was in making text messaging real-time, rather than just asynchronous store-and-forward delivery into a mailbox. It started with Internet service provider America Online (AOL) as a public Internet-based free text “chat” service for consumers, but soon was being used by business people as well. It introduced the concept of Internet Protocol “presence management” or being able to detect device connectivity to the Internet and contact recipient “availability” status to exchange real-time messages, as well as personalized “Buddy list” directories to allow only people you knew to find out your status and initiate a real-time text messaging exchange with you. Presence and Instant Messaging has since evolved into more than short text messages, but now can include the exchange of data files (documents, pictures) and the escalation of the contact into a voice conversational connection.

Voice messaging with mobile devices

The increase in wireless mobility, originally through cellular services and today through IP-based Wi-Fi, was also a driver for messaging convergence with mobile telephony. Today it is not only fostering the use of speech user interfaces for message management, but increasing the demand for retrieval of voice messages integrated with email. It also enables people to reply to both voice and email messages in voice rather than text. New services, such as GotVoice and SpinVox, are helping to blur the boundaries between voicemail and text by delivering voicemails to mobile phones as SMS text messages.

Unified messaging with voip/ip telephony

Corporate voicemail, however, did not change much until the advent of Voice over IP(VoIP — voice being transmitted over the internet) and the development of IP telephony applications to replace legacy PBX telephony (called TDM technologies). IP (Internet Protocol) telephony changed the style and technology of PBXs and the way voicemail systems integrated with them. This, in turn, facilitated a new generation of Unified Messaging, which is now likely to catch on widely. The flexibility, manageability, lower costs, reliability, speed, and user convenience for messaging convergence is now possible where it wasn’t before. This might include intra- and inter-enterprise contacts, mobile contacts, proactive application information delivery, and customer contact applications.

The corporate IP telephony-based voicemail CPEmarket is served by several vendors including Avaya, Cisco systems, Adomo, Interactive Intelligence[2], Nortel, Mitel, 3Com, and AVST[5]. Their marketing strategy will have to address the need to support a variety of legacy PBXs as well as new Voice over IP as enterprises migrate towards converging IP-based telecommunications. A similar situation exists for the carrier market for voicemail servers, currently dominated by Comverse Technology, with some share still held by Lucent Technologies.

VoIP and IP telephony enable centralized, shared servers, with remote administration and usage management for corporate (enterprise) customers. In the past, carriers lost this business because it was far too expensive and inflexible to have remote managed facilities by the phone company. With VoIP, remote administration is far more economical. This technology has re-opened opportunities for carriers to offer hosted, shared services for all forms of converged IP telecommunications, including IP-PBX and voicemail services. Because of the convergence of wired and wireless communications, such services may also include support of a variety of multi-modal handheld and desktop end user devices. This service, when offered for multiple extensions or phone numbers is sometimes also called Unified Voicemail.