Cisco voice communication model is a four layered model, comprising of following layers – Infrastructure, Call processing, Application and endpoints.

All these layers devices, applications work together and complement each other to deliver the ultimate functionality of a converged VOIP network.  At the Infrastructure Layer commonly used devices are routers, switches, gateways and security products like firewall, Intrusion detection / prevention systems, encryption etc.  Infrastructure layer provides the functionality to ensure basic call functions are achieved like call making, receiving, hold, redial, forwarding, management and administration, Quality of service (QoS), high availability, voice security and multicasting capabilities.

The next layer in the stack of Cisco communication model is Call Processing Layer; this layer is responsible for processing of calls starting from call generation, routing to termination of calls, directory services, and phone features administration and so on.  Cisco Call manager offers the functionality of call processing layer and it is available in four flavors depending on the requirement and size of enterprises.  Cisco Unified Communication Manager can support users range from 48 users to 30,000+ users.  It also gives functionality of backup and restore from disaster recovery perspective ensuring to keep backup of all call records, call management records and reporting.

Next layer in the layered model is Application Layer which supports a variety of functions depending on varied users and businesses requirement.  Messaging functionality in a VOIP environment is a feature rich offering which enable message delivery to variety of clients such as fax messages, voicemail, and email from a single mailbox.  Cisco unity product line comes in three variations and it is an out of the box product which offers complete messaging solution for VOIP networks.  The three variations give user support from 250 to 25,000 users per network.  Apart from messaging there are some other functions and applications which businesses demand resulting from all time need for connectivity and communication.

Applications like auto attendants and Interactive voice response systems are commonly used by today’s businesses and by varied industries for diverse business requirements, to improve customer experience, reduce the operational and manpower costs.  Customer care divisions are the most desirable candidates of these functionalities.   Auto attendants enable forwarding of extensions to desired personnel without the intervention of operator.  An IVR gives much more advanced functionality where caller can feed in or speak their requirement and system intelligently directs the call to an auto response or a desired skill set agent for response.

Other applications like contact centers enable businesses to handle large volume of customer support calls, by intelligently routing calls to agents.  An automatic call distribution service facilitates the distribution of calls to different groups, previous history of caller can be extracted to better service his/ her requirement and this can be integrated with IVR systems also.

Mobility solutions facilitate users to assign single number for multiple devices such as desktop phones, cell phones, instant messenger clients and so on.  Unanswered calls are redirected to an organization mailbox.   Mobility solutions help to integrate multiple lines of communication as it would be very tedious for a caller to every time dial different numbers (Business, home, mobile phones) or leave voicemails to different voice mailboxes.

Telepresence is the real-time virtual alternative of face to face meetings with customers, clients, and stakeholder’s people with whom organizations conduct businesses. They save the high recurring costs of travelling, boarding/loading, and hiring of costly web conferencing facilities from 3rd party sources.  It is real-time experience of a live meeting / conference with high quality video /audio presence. Conferences can be recorded and played back as needed.

Unified Presence let us collaborate more effectively and efficiently with our business partners, associates, customers and reduce time to reach market, improve customer experience by identifying the availability of a personnel irrespective of their location.

Emergency responder’s helps to direct calls to public emergency systems from a distress call of a caller and identify its location on immediate basis.  Example of one such system is US emergency number 911.

The final and the topmost and only layer of Cisco voice communication layered model which interacts with user is the Endpoint Layer. The endpoint layer brings applications to users whether the end device is a Cisco IP phone, a PC using software based phone, or a communications client on a video terminal. Cisco UC provides multiprotocol support for skinny client control protocol (SCCP), H.323, MGCP and SIP.

This layer performs two major functions – provides basic functionality such as making.  Receiving calls, hold, redial, conferencing, transfer etc and secondly support for voice and video integration devices.

Different business functions entails different function requirements based on that various types of endpoint devices are available in the market – depending on the requirement one can make a right choice and achieve the desired functionality.  These devices are designed keeping in mind the areas where they have been ideally used such as public places, lobbies, executive rooms, manufacturing floors and so on.  Endpoint devices comes with single line, multiple line, standard telephony features like call making, receiving, hold, redial, transfer , mute, speaker, voicemail access and so on.  The IP phones with advanced feature set like gigabit Ethernet port for integration to PC or desktop server, wideband audio support, high resolution, backlit display, hands free speaker phone, support to XML applications, integration with 3rd party applications and so on.

The Cisco UC product suite offers a complete end-to-end solution for a fully converged VOIP network which provides IP telephony – the capability to transmit voice communications over an IP network, customer contact centers to improve customer communication across large networks by facilitating callers to access a large pool of agents and multiple channels of communication and self help tools. Real time video communications and collaboration support to give real life face to face meeting experience, and integration with 3rd party services and applications like messaging, customer care and workforce optimization to enhance productivity , connectivity, and customer experience.

Cisco UC network delivers a fully integrated communications converging voice, video and data over a single network infrastructure. Figure 1 illustrates how all components of layered model work together to deliver a completely converged and integrated voice network to an enterprise.

Figure 1: UC network

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