Cisco Contact Center Architecture
This chapter discusses the following main Cisco Contact Center products and related features:
- Cisco Unified Communications Manager (Unified CM) call queuing feature
- Cisco Unified Contact Center Enterprise (Unified CCE)
- Cisco Unified Customer Voice Portal (Unified CVP)
- Cisco Unified Contact Center Express (Unified CCX)
Cisco Unified CM Call Queuing
The Cisco Unified CM call queuing feature provides the capability for queuing the incoming callers to a hunt pilot number. With this option enabled, callers to the hunt pilot can be put in queue to wait for an available agent that is configured as a hunt member to answer the call. Callers receive an initial greeting announcement when they first enter the queue, and they hear periodic announcements while they are in queue. When an agent becomes available, the call is taken out of the queue and answered by the agent. For customers who need a basic contact center with very limited functionality, Cisco Unified CM call queuing can be an option. However, unlike the full-featured Cisco Contact Center products, the Unified CM call queuing option lacks much of the contact center functionality such as agent desktop, supervisor, and reporting capabilities. If customers require complete contact center functionality, Cisco Unified Contact Center Enterprise or Cisco Unified Contact Center Express should be used.
The hunt pilot line members can display the queue status about their associated hunt pilots from the phone screen, and the queue status provides the following information:
- Hunt pilot number
- Number of calls waiting in the queue
- Longest call waiting time
In addition, Unified CM call queuing provides statistics on the number of calls currently waiting in queue and the longest call waiting time, along with other statistics, through the serviceability counters based on the hunt pilot number. This allows the supervisor to monitor the queue status using the Real Time Monitoring Tool (RTMT).
For each hunt pilot, callers can be routed to an alternate configurable destination such as voicemail or another hunt pilot if any of the following situations occurs:
- The number of calls in the queue reaches the maximum that is set by the Maximum Number of Callers Allowed in Queue parameter.
- The wait time of a caller in queue exceeds the threshold that is configured by the Maximum Wait Time in Queue parameter.
- No hunt members are logged in or registered.
Note For calls routed to the queue-enabled hunt pilot number through a SIP trunk, the SIP Rel1XX Options should be set to Send PRACK if 1XX contains SDP in the SIP profile associated with the SIP trunk.
For additional information on the Unified CM call queuing option, refer to the latest version of the System Configuration Guide for Cisco Unified Communications Manager, available at
Cisco Unified Contact Center Enterprise
Cisco Unified Contact Center Enterprise (Unified CCE) provides a contact center solution that enables you to integrate inbound and outbound voice applications with Internet applications, including real-time chat, Web collaboration, and email. This integration provides for unified capabilities, helping a single agent support multiple interactions simultaneously, regardless of the communications channel the customer has chosen. Because each interaction is unique and may require individualized service, Cisco provides contact center solutions to manage each interaction based on virtually any contact attribute. The Unified CCE deployments are typically used for large size contact centers and can support thousands of agents.
There is also a predesigned, bounded deployment model of Unified CCE: Cisco Packaged Contact Center Enterprise (Packaged CCE). Customers whose contact center requirements fit the boundaries of the solution can enjoy the advantages of the simplified management interface, smaller hardware footprint, and reduced time to install. Those customers can also benefit from the comprehensive feature set of Cisco Unified Contact Center Enterprise and Cisco Unified Customer Voice Portal. The solution comes packaged with Cisco Unified Intelligence Center for comprehensive reporting and Cisco Finesse desktop software for an enhanced, next-generation desktop experience. For more details on Packaged CCE, refer to the documentation at the following locations:
Unified CCE employs the following major software components:
The Call Router makes all the decisions on how to route a call or customer contact.
The Logger maintains the system database that stores contact center configurations and temporarily stores historical reporting data for distribution to the data servers. The combination of Call Router and Logger is called the Central Controller.
The Peripheral Gateway (PG) interfaces to various "peripheral" devices, such as Cisco Unified CM, Cisco Unified IP Interactive Voice Response (Unified IP IVR), Cisco Unified CVP, or multichannel products such as Cisco Unified Web Interaction Manager (Unified WIM) and Cisco Unified E-Mail Interaction Manager (Unified EIM). A Peripheral Gateway that interfaces with Unified CM is also referred to as an Agent PG.
- CTI Server and CTI Object Server (CTI OS)
The CTI Server and CTI Object Server interface with the agent desktops. Agent desktops can be based on the Cisco Finesse agent and supervisor desktops, Finesse IP Phone Agent, or customer relationship management (CRM) connectors to third-party CRM applications.
- Administration & Data Server
The Administration & Data Server provides a configuration interface as well as real-time and historical data storage.
The Cisco Unified CCE solution is based on the integration with Cisco Unified Communications Manager (Unified CM), which controls the agent phones. For deployments without Unified CM but with traditional ACD, use Cisco Unified Intelligent Contact Management Enterprise (Unified ICME) instead of Unified CCE.
The queuing and self-service functions are provided by Cisco Unified IP Interactive Voice Response (Unified IP IVR) or Cisco Unified Customer Voice Portal (Unified CVP) and are controlled by the Unified CCE Call Router.
Most of the Unified CCE components are required to be redundant, and these redundant instances are referred to as side A and side B instances. For example, Call Router A and Call Router B are redundant instances of the Call Router component running on two different virtual machines.
Agents can use a large variety of endpoints, including some video endpoints and some Cisco TelePresence endpoints such as the Cisco DX70 and DX80. For a list of supported endpoints, refer to the Compatibility Matrix for Unified CCE, available at
Cisco Unified Customer Voice Portal
Cisco Unified Customer Voice Portal (Unified CVP) provides carrier-class voice and video IVR services on Voice over IP (VoIP) networks. It can perform basic prompt-and-collect or advanced self-service applications with CRM database integration and with automated speech recognition (ASR) and text-to-speech (TTS) integration. Unified CVP also provides IP-based call switching services by routing and transferring calls between voice gateways and IP endpoints.
Unified CVP is based on the Voice Extension Markup Language (VXML), which is an industry standard markup language similar to HTML and which is used to develop IVR services that leverage the power of web development and content delivery.
The Unified CVP solution employs the following main components:
The Unified CVP Call Server provides call control capabilities for SIP services. The Unified CVP Call Server can also integrate with the Unified CCE Call Router through the Intelligent Contact Management (ICM) service. The IVR service provides a platform to run VXML Micro applications and to create VoiceXML pages.
This component executes complex IVR applications by exchanging VoiceXML pages with the VoiceXML gateway's built-in voice browser. Unified CVP VXML applications are written using Cisco Unified Call Studio and are deployed to the Unified CVP VXML Server for execution. Note that there is no RTP traffic going through the Unified CVP Call Server or the Unified CVP VXML Server.
The Cisco Voice Gateway is the point at which a call enters or exits the Unified CVP system. The Cisco Voice Gateway could have a TDM interface to the PSTN. Alternatively, Cisco Unified Border Element could be used when the interface to the PSTN is an IP voice trunk.
The VoiceXML Gateway hosts the Cisco IOS Voice Browser. This component interprets VoiceXML pages from either the Unified CVP Server IVR Service or the Unified CVP VXML Server. The VoiceXML Gateway can play prompts based on.wav files to the caller and can accept input from the caller through DTMF input or speech (when integrated with Automatic Speech Recognition). It then returns the results to the controlling application and waits for further instructions.
The Cisco VoiceXML Gateway can be deployed on the same router as the Cisco Voice Gateway. This model is typically desirable in deployments with small branch offices. But the VoiceXML Gateway can also run on a separate router platform, and this model might be desirable in large or centralized deployments with multiple voice gateways.
A video media server in a Unified CVP comprehensive deployment enables video streaming for the Video in Queue feature. Cisco MediaSense or Cisco TelePresence Content Server can be used as a video media server.
Unified CVP can be deployed standalone or integrated with Unified CCE to offer voice and video self-service and queuing functions. The Unified CVP solution now supports the G.711 a-law codec end-to-end.
The Basic Video Service in Unified CVP is available when Unified CVP is deployed along with Cisco Contact Center Enterprise (Unified CCE) in a comprehensive deployment model. This service allows a video caller to interact with an audio-only IVR and subsequently connect with a video agent. It supports Cisco TelePresence endpoints such as the Cisco DX70 and DX80 as customer and agent endpoints. The video agents can also conference in a second audio-only agent by dialing a direct extension from their phone.
Video in Queue (VIQ) Basic Video is an optional feature in Unified CVP, and it can be enabled to play video to callers while they wait for a video-enabled agent or expert. Cisco MediaSense or Cisco TelePresence Content Server enables the video streaming. The caller can subsequently connect to a video agent.
For more information on Unified CVP system design and detailed call flows, refer to the latest version of the Cisco Unified Customer Voice Portal Design Guide, available at
Cisco Unified Contact Center Express
Cisco Unified Contact Center Express (Unified CCX) meets the needs of departmental, enterprise branch, or small to medium-sized companies that need easy-to-deploy, easy-to-use, highly available and sophisticated customer interaction management for up to 400 agents. It is designed to enhance the efficiency, availability, and security of customer contact interaction management by supporting a highly available virtual contact center with integrated self-service applications across multiple sites. To simplify the deployment, Unified CCX can be preloaded on a Cisco Business Edition 6000 or 7000 system.
Unified CCX integrates with Unified CM by means of JTAPI for call control. All the Unified CCX components, including the Unified CCX engine, Unified CCX database, Finesse Server, Unified CCX Outbound Dialer, Cisco Unified Intelligence Center, and Express E-mail Manager, are installed on a single virtual machine. For system redundancy, a second identical Unified CCX instances can be added to the deployment.
Unified CCX has built-in capabilities for inbound audio and video calls, silent monitoring, and Cisco Unified Intelligence Center reporting. Additional licensing and components can enhance the solution to support outbound dialing, call recording, email, chat, social network monitoring, and workforce optimization.
Unified CCX supports advanced features such as Automated Speech Recognition (ASR) and Text to Speech (TTS), HTTP, and VXML. It also supports products such as Cisco Unified Workforce Optimization to optimize performance and quality of the contact center. Agents can use a variety of video endpoints such as the Cisco Unified IP Phone 9900 Series with camera. For a list of supported endpoints, refer to the latest version of the Unified CCX Software Compatibility Matrix, available at
Cisco Unified CCX includes IP IVR functionality for prompting, collecting, and queuing during customer inbound calls.
Cisco SocialMiner is a social media customer-care solution that can help you proactively respond to customers and prospects by communicating through public social media networks such as Twitter, Facebook, or other public forums or blogging sites. By providing social media monitoring, queuing, and workflow to organize customer posts on social media networks and deliver them to your social media customer care team, your company can respond to customers in real time using the same social network the customers are using. For more information, refer to the documentation available at
Universal Queue for Third-Party Multichannel Applications
Universal Queue describes the system's ability to route requests from various media channels to any agents in a contact center.
You can configure agents to handle a combination of voice calls, emails, chats, and so on. For example, you can configure an agent as a member of skill groups or precision queues in three different Media Routing Domains (MRDs) if the agent handles voice, email, and chat. You can design routing scripts to send requests to these agents based on business rules, regardless of the media. Agents signed into multiple MRDs may switch media on a task-by-task basis.
Universal Queuing APIs provide a standard way to request, queue, route, and handle third-party multichannel tasks in Unified CCE. (See Figure 22-1.)
Contact Center customers or partners can develop applications using Cisco SocialMiner and Cisco Finesse APIs in order to use Universal Queue. The SocialMiner Task API enables applications to submit non-voice task requests to Unified CCE. The Finesse APIs enable agents to sign into various types of media and handle the tasks. Agents sign into and manage their state in each media independently.
Cisco partners can use the sample code available on Cisco DevNet ( https://developer.cisco.com/site/devnet/home/index.gsp) as a guide for building these applications.
Figure 22-1 Universal Queue for Third-party Multichannel Applications Solution Components
SocialMiner and Universal Queue
Third-party multichannel applications use SocialMiner's Task API to submit non-voice tasks to Unified CCE. The API works in conjunction with SocialMiner task feeds, campaigns, and notifications to pass task requests to the contact center for routing.
The Task API supports the use of Call variables and Extended Call Context (ECC) variables for task requests. Use these variables to send customer-specific information with the request, including attributes of the media such as the chat room URL or the email handle.
Unified CCE and Universal Queue
Cisco Unified CCE provides the following functionality as part of Universal Queue:
- Processes the task request
- Provides estimated wait time for the task request
- Notifies SocialMiner when an agent has been selected
- Routes the task request to an agent, using either skill group or precision queue routing
- Reports on contact center activity across media
Finesse and Universal Queue
Cisco Finesse provides Universal Queue functionality via the Media API and Dialog API. With the Media API, agents using third-party multichannel applications can:
- Sign into multiple MRDs
- Change state in multiple MRDs
With the Dialog API, agents using third-party multichannel applications can handle tasks from multiple MRDs.
Administration and Management
Cisco Contact Center products have built-in administration and management capabilities. For example, Unified CCE can be administered using either the Configuration Manager tool that is installed with Unified CCE or the web-based administration tools for simplified execution of the most common administration and management tasks in the Contact Center Enterprise environment. In addition, REST API support allows third-party developers to create applications that can control many of the administration and support tasks.
Unified CVP can be administered with the Unified CVP Operations Console, also known as Operations, Administration, Maintenance, and Provisioning (OAMP).
In addition, Cisco Unified Contact Center Management Portal (Unified CCMP) can be deployed to simplify the operations and procedures for performing basic administrative functions such as managing agents and equipment. Unified CCMP is a browser-based management application designed for use by contact center system administrators, business users, and supervisors. It is a dense multi-tenant provisioning platform that overlays the Cisco Unified CCE, Unified CM, and Unified CVP equipment.
Cisco Unified Intelligence Center is the main reporting tool for the Cisco Contact Center solutions. It is supported by Unified CCE, Unified CCX, and Unified CVP. This platform is a web-based application offering many Web 2.0 features, high scalability, performance, and advanced features such as the ability to integrate data from other Cisco Unified Communications products or third-party data sources.
Cisco Unified Intelligence Center gets source data from a database, such as an Unified CCE Administration & Data Server database or the Unified CVP Reporting Informix database. Reports are then generated and provided to a reporting client.
The Cisco Unified Enterprise solution supports web interaction and email interaction for multichannel support. Cisco Unified Web Interaction Manager (Unified WIM) technology helps ensure that communication can be established from nearly any web browser. Cisco Unified E-Mail Interaction Manager (Unified EIM) provides inbound email routing, automated or agent assisted email responses, real-time and historical reporting, and role-based hierarchical rights management for agents, supervisors, administrators, and knowledge base administrators.
For more design information on these products, refer to the Cisco Unified E-Mail and Web Interaction Manager Solution Reference Network Design Guide, available at
Recording and Silent Monitoring
Cisco Unified Contact Center solutions provide recording and silent monitoring capabilities based on the following mechanisms:
- The SPAN feature in Cisco switches
This feature replicates the network traffic to a destination port to which a Cisco contact center server is connected.
- Unified CM and media replication by the built-in-bridge (BIB) in Cisco IP Phones
With this option, Unified CM is involved in setting up the recording flows and can perform call admission control for those flows. This option can be used with Cisco MediaSense, for example.
- Media forking by Cisco Unified Border Element gateway
This option can be used with Cisco MediaSense, for example.
For more details on call recording and monitoring, see the chapter on Call Recording and Monitoring.
Contact Sharing enables large contact centers to grow larger. Centralized self-service (IVR ICM deployment model) uses a Contact Sharing routing node to distribute calls to two Unified CCE instances for horizontal scaling. Live Data is a prerequisite for Contact Sharing and must be installed and configured prior to use of Contact Sharing. Contact Sharing also requires the IVR Cisco Intelligent Contact Management (ICM) deployment model to be enabled in the deployment. For details about Contact Sharing, refer to the latest version of the Cisco Unified Contact Center Enterprise Features Guide, available at
Context Service is a cloud-based storage service that provides a repository for customer journey data. It enables Cisco Contact Center customers to deliver a seamless omnichannel experience through integration with other Cisco Customer Collaboration products as well as APIs for third-party integration, as depicted in Figure 22-2.
Figure 22-2 Context Service Integration
Context Service allows any application to write and read customer journey activity. Cisco Contact Center customers, referred to in this section as the business, have access to Context Service from within their Cisco Contact Center platforms. The Cisco Contact Center platforms are enabled and optionally configured to post context data about contact center interactions.
Context Service stores this data in an element called a Piece of Data (POD). A POD can store any metadata about the consumer interaction, except for the media (such as audio recording). Businesses choose which fields (metadata) to store in the POD and the level of data privacy for each field. PODs can be organized by customer and also grouped together as part of a collection of interactions called a Request (see Figure 22-3). Context Service also provides tagging capability to group PODs for correlation, trending, and analytics.
Figure 22-3 Pieces of Data (PODs) and Requests
Context Service is hosted on Cisco Intercloud, which is an ecosystem of Cisco and partner data centers that is managed and operated by the Cisco data center team across the globe. Context Service follows a data privacy model very similar to Cisco Spark, in which each business controls access to its data. The data is encrypted/decrypted on-premises at the client and stored as an encrypted blob in Cisco data centers. Businesses can choose to host the encryption keys (Keystore) on their premises. This is analogous to valuables stored in a safety deposit box (locker) at a bank; even though the valuables are in the bank, the customer has the key to the deposit box and controls access to it. This is a newer approach to data privacy, and it puts the customer in control without the overhead of hosting a private cloud. Context Service provides a level of data privacy classification so that businesses can store their customers’ Personally Identifiable Information (PII) separately from other encrypted data, and thereby allowing businesses to provide third-party analytics vendors with controlled access to their encrypted data without giving access to their customers’ PII data.
Context Service can store data for Universal Queue task contacts. When Context Service is enabled, SocialMiner selects pieces of data from an incoming task request and saves it in a POD in the cloud. You can specify the media type of the POD in the task request. If you don't specify the media type, then the media type event is set to the POD.
Context Service is managed by Cisco Collaboration Management (Atlas), which is the management portal for all Cisco cloud collaboration offerings, including Cisco Spark. Cisco partners and businesses use Collaboration Management to connect on-premises clients, manage the POD data model (fields), monitor POD usage, and so forth.
Context Service provides an open API and Java/JS SDK to make it easy for technology partners to integrate their applications with Context Service.
For more details on Cisco Context Service, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Connected Analytics for Contact Center
Cisco Connected Analytics for Contact Center (CACC) is an analytics software and services solution that uses data from Cisco Contact Center Enterprise (CCE) to improve agent effectiveness and reduce customer effort during the call process. A recent study shows that the characteristic with the greatest influence on customer spending, lifetime value, loyalty, and positive word of mouth is the amount of time or effort customers have to put forth to resolve their issues. The second most influential characteristic is agent effectiveness at resolving customer issues.
Cisco CACC takes an innovative approach to capture these two key indicators. Using Cisco proprietary analytical models, CACC pulls data from your contact center to mathematically derive a customer effort profile score and an agent effectiveness score for each customer interaction. With strategic insight from your contact center data, you can increase contact center efficiency and improve the customer experience.
Features and Capabilities
Analytics such as call analysis, wrap-up code analysis, and agent analysis can boost operational efficiency in the call center. This helps lower operating costs and boost revenue by enabling you to:
- Reduce the number of repeat calls from customers.
- Track agent performance to pinpoint areas for improvement.
- Train agents for better agent retention.
Improve your customer care by analyzing the customer call experience to pinpoint areas for improvement. You can strategically improve your customer satisfaction scores by using analytics to:
- Analyze call history to improve first contact resolution.
- Know your most effective agents and their expertise for better call routing.
- Reduce the burden on customers in the call process.
For further information on Connected Analytics for Contact Center, refer to the product documentation at
Cisco Prime Collaboration Contact Center Assurance
Cisco Prime Collaboration provides efficient, integrated service-assurance management through a single consolidated view of the Cisco Contact Center Enterprise architecture. This management includes continuous real-time monitoring and advanced troubleshooting tools, and it offers monitoring and diagnostics that help reduce costly Cisco Unified Contact Center Enterprise downtime and promote agent productivity. Table 22-2 lists the main features and benefits of Cisco Prime Collaboration Contact Center Assurance.
Table 22-2 Cisco Prime Collaboration Contact Center Assurance Features
Functionality and Benefits
Simplify operations using a real-time visual representation of Cisco Unified Contact Center infrastructure availability, including faults at the device and site levels. Operators can easily act on faults from the device 360-degree view. (See Figure 22-4.)
Event correlation and reduction tailored to the Cisco Unified Contact Center Enterprise deployment
Isolate the root cause of problems using built-in correlation rules specific to Cisco Unified Contact Center Enterprise deployments to correlate event data and generate alarms (see Figure 22-5). Reduce mean time to recovery (MTTR).
Proactively detect and address performance problems with a view of critical Cisco Unified Contact Center Enterprise key performance indicators (KPIs), thus avoiding costly service interruptions.
SIP call trace and analysis
Easily identify network and Cisco Unified Contact Center Enterprise devices causing call failures and reduce MTTR using a graphic depiction of detailed call log information. (See Figure 22-6.)
Figure 22-4 Contact Center Assurance Topology View
Figure 22-5 Alarms
Figure 22-6 Call Trace
Cisco Virtualized Voice Browser
Cisco Virtualized Voice Browser (Cisco VVB) provides a platform for interpreting VoiceXML documents. When a new call arrives at the contact center, the VVB allocates a VXML port that represents the VoIP endpoint. Cisco VVB sends HTTP requests to the Cisco Unified Customer Voice Portal (Unified CVP) VXML server. In response to the HTTP request, the Unified CVP VXML server executes the request and sends a dynamically generated VXML document. For more information about Cisco VVB, refer to the Cisco Virtualized Voice Browser design considerations and installation and configuration options documented in the latest version of the Installing and Configuring Guide for Cisco HCS, available at
Contact Center Deployment Models
This section describes the various design models used for deploying Cisco Unified Contact Center solutions. For more details on these deployment models, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Single-Site Contact Center
In this deployment, all the components such as call processing agents, voice gateways, and contact center applications are in the same site. Agents and supervisors are also located at that site. The main benefit of the single-site deployment model is that there is no WAN connectivity required and, therefore, no need to use a low-bandwidth codec such as G.729, transcoders, compressed Real-Time Transport Protocol (cRTP), or call admission control.
Multisite Contact Center with Centralized Call Processing
A multisite deployment with centralized call processing consists of a single call processing cluster that provides services for many remote sites and uses the IP WAN. Cisco Contact Center applications (Unified CCE, Unified CCX, and Unified CVP) are also typically centralized to reduce the overall costs of management and administration. Figure 22-7 illustrates this type of deployment.
Figure 22-7 Multisite Contact Center with Centralized Call Processing
Because the agents or the voice gateways in this type of deployment are located in remote sites, it is important to consider the bandwidth requirements between the sites. It is also important to carefully configure call admission control, Quality of Service (QoS), codecs, and so forth. For more information on the general design considerations for Unified Communications solutions, refer to the chapter on Collaboration Deployment Models.
Contact center deployments in a Unified Communications system typically have the following additional bandwidth requirements:
- The traffic volume handled by the agents is higher than that of typical users, and therefore voice and signaling traffic is also higher for agents.
- Agents and supervisors use desktops with screen popup, reports and statistics, and so forth. This causes data traffic between the agent or supervisor desktops and the contact center servers. In addition, bandwidth calculations must account for reporting information if, for example, an agent or supervisor is remote and pulls data from a server in a central location. For more information and guidance, refer to the design guides for the individual Cisco Contact Center products, available at http://www.cisco.com/go/ucsrnd.
- Depending on type of IVR solution, there could be traffic between the voice gateway and the IVR system. For example, if the voice gateways are distributed and calls arrive at a voice gateway located in a remote site with Unified IP IVR, there would be voice traffic across the WAN between the voice gateway and Unified IP IVR. With Unified CVP, the call could be queued at the remote site, with the VXML Gateway providing call treatment and queuing and therefore avoiding voice traffic across the WAN for IVR and reducing overall WAN bandwidth requirements.
Remote agents (for example, agents working from home) are also supported with Cisco Unified Contact Center. There are mainly two solutions. The first one requires the agent to use an IP phone that is connected to the central site by a broadband internet connection. In this solution, the phone is CTI controlled by the Cisco Unified Contact Center application. The second solution is based on Cisco Unified Mobile Agent, which enables an agent to participate in a call center with any PSTN phone such as cell phone.
Multisite Contact Center with Distributed Call Processing
The model for a multisite deployment with distributed call processing consists of multiple sites, each with its own call processing cluster connected to an IP WAN. This section assumes that each Unified CM cluster has agents registered to it.
A Unified CCX deployment cannot be shared across multiple Unified CM clusters. Each Unified CM cluster requires its own Unified CCX deployment, as illustrated in Figure 22-8.
Figure 22-8 Multisite Unified CCX Deployment with Distributed Call Processing
Requirements for Unified CCE differ from Unified CCX. A single Unified CCE system can span across multiple Unified CM clusters distributed across multiple geographic locations. A Unified CCE Agent PGs must be installed in each Unified CM cluster location and could be physically remote from the Unified CCE Central Controller (Call Router + Logger). Figure 22-9 illustrates this type of deployment and highlights the placement of the Agent PG.
Figure 22-9 Multisite Unified CCE Deployment with Distributed Call Processing
If you require multiple contact center deployments, you could connect those deployments through Unified ICM by using the parent/child deployment model to form a single virtual contact center. The parent/child model provides several benefits, such as enterprise queuing and enterprise reporting across all the contact center deployments. It also provides complete site redundancy and higher scalability. For more details on the parent/child model, refer to the following documents:
- Cisco Unified Contact Center Enterprise Design Guide, available at
- Cisco Contact Center Gateway Deployment Guide for Cisco Unified ICME/CCE, available at
Similarly to the multisite model with centralized call processing, multisite deployments with distributed call processing require careful configuration of QoS, call admission control, codecs, and so forth.
Clustering Over the IP WAN
In this deployment model, a single Unified CM cluster is deployed across multiple sites that are connected by an IP WAN with QoS features enabled. Cisco Unified Contact Center solutions can be deployed with this model. In fact, the Cisco Unified Contact Center components themselves can also be clustered over the WAN.
For example, with Unified CCE, the side A components could be remote from the Unified CCE side B components and separated from them by an IP WAN connection. (For more details on Unified CCE high availability, see High Availability for Contact Centers.) The following design considerations apply to this type of deployment:
- The IP WAN between the two sites must be highly available, with no single point of failure. For example, the IP WAN links, routers, and switches must be redundant. WAN link redundancy could be achieved with multiple WAN links or with a SONET ring, which is highly resilient and has built-in redundancy.
- The Agent Peripheral Gateway (PG) and the CTI Manager to which it is connected must be located in the same data center. Because of the large amount of redirect and transfer traffic and additional CTI traffic, the Intra-Cluster Communication Signaling (ICCS) bandwidth requirements between the Unified CM nodes are higher when deploying Unified CCE.
- If the primary Unified CCE and Unified CM nodes are located in one site and the secondary Unified CCE and Unified CM nodes are in another site, the maximum latency between the two sites is dictated by the Unified CM latency requirement of 80 ms round trip time (RTT). However, if the Unified CCE nodes are in different locations than the Unified CM nodes, it is possible to have a higher latency between the redundant Unified CCE nodes.
Figure 22-10 illustrates a deployment of Unified CCE using clustering over the WAN. For more details, refer to the Cisco Unified Contact Center Enterprise Design Guide, available at
Figure 22-10 Unified CCE Deployment with Clustering Over the WAN
With Unified CCX and Unified IP IVR solutions, the primary Unified CCX or Unified IP IVR node could also be remote from the backup node. The requirements for Unified CCX deployments are different than the ones for Unified CCE deployments. For example, redundant WAN links are not required with Unified CCX. Also, the maximum latency between the primary and backup Unified CCX nodes is 80 ms RTT. Figure 22-11 illustrates this type of deployment. For more details, refer to the Cisco Unified Contact Center Express Design Guide, available at
Figure 22-11 Unified CCX Deployment with Clustering Over the WAN
Design Considerations for Contact Center Deployments
This section summarizes the following major design considerations for contact center deployments:
High Availability for Contact Centers
All Cisco Unified Contact Center products provide high availability. For example, with Unified CCX or Unified IP IVR, you could add a second identical Unified CCX or Unified IP IVR node to provide high availability. The second node can reside in the same data center as the primary node or, if geographic redundancy is required, the second node can reside in a different data center across the WAN from the primary node (see Clustering Over the IP WAN). One of the nodes would be the active node and would handle all the call processing. The other node would be in standby mode and become active only if the primary node fails. Unified CVP also supports high available deployments with multiple Unified CVP nodes, voice gateways, VXML gateways, SIP proxies, and so forth.
With Unified CCE, most of the components are required to be redundant, and the redundant instances are referred to as side A and side B instances. For example, Call Router A and Call Router B are redundant instances of the Call Router module (process) running on two different virtual machines. This redundant configuration is also referred to as duplex mode. The Call Routers run in synchronized execution across the two instances, which means both sides of the duplex instances process every call. Other components, such as the Peripheral Gateways, run in hot-standby mode, meaning that only one of the Peripheral Gateways is actually active at any given time.
In addition to the redundancy of the Unified Contact Center components themselves, their integration with Unified CM can also be redundant. For example, each Unified CCX or Unified IP IVR node can connect to a primary CTI Manager and also to a backup CTI Manager in case the primary CTI Manager fails. With Unified CCE, a PG side A would connect to a primary CTI Manager, while the redundant PG side B connects to the secondary CTI Manager, thus providing high availability if one CTI Manager fails.
For more details, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Bandwidth, Latency, and QoS Considerations
This section describes how to provision WAN bandwidth in a multisite contact center deployment, taking into account various types of call control traffic and real-time voice traffic. It is important to understand the latency and QoS parameters because adequate bandwidth provisioning and implementation of QoS are critical components in the success of contact center deployments.
Contact center solutions require sufficient WAN bandwidth to accommodate the following main types of traffic:
- Voice traffic between the ingress gateway and the IVR system. With Unified IP IVR, if the Unified IP IVR cluster is in a central location and PSTN gateways are in remote locations, there will be voice traffic over the WAN. With Unified CVP, it is possible to queue the call at the edge and therefore keep the voice traffic local to the remote site to avoid voice traffic across a WAN link. Video queuing is also supported with the Unified CVP Video in Queue (ViQ) feature, so also consider the video traffic between the caller and the video media server.
- Voice traffic between the ingress gateway and the agent, or voice traffic between the caller and agent for internal calls. There could also be video traffic between the caller and the agent if the contact center deployment supports video.
- Voice and video signaling traffic. This is typically for the signaling traffic between the ingress gateway or caller endpoint and Unified CM, and between the agent phone and Unified CM.
- VXML Gateway traffic if Unified CVP is deployed. The traffic includes media file retrieval from the media server and VXML documents exchanged with the VXML server.
- Data traffic between the Finesse agent or supervisor desktop and the application server(s) hosting Finesse gadgets.
- Reporting traffic between the reporting user and the Unified Contact Center Reporting server.
- Traffic between Unified Contact Center servers if they are remote from each other. For example, this type of traffic occurs with clustering over the IP WAN or with multisite and distributed call processing with PGs remote from the Unified CCE Central Controller.
- Additional Intra-Cluster Communication Signaling (ICCS) traffic between the Unified CM subscribers due to the large amount of redirect and transfer traffic and additional CTI traffic.
- Voice traffic due to recording and silent monitoring. Depending on the solution, one or two RTP streams could be sent in order to silently monitor or record the conversation with an agent.
Bandwidth calculations and guidelines are provided in the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Agents and supervisors can be located remotely from the call processing components and the contact center. Technically, the delay between the Finesse Server and the Finesse desktop could be very high because of high time-out values. Long latency will affect the user experience and might cause confusion or become unacceptable from the user perspective. For example, the phone could start ringing but the desktop might not be updated until later.
Latency requirements between the contact center and the call processing components, and between the contact center components themselves, depend on the contact center solutions. For example, the Unified CCX redundant nodes can be located remotely from each other, with a maximum latency of 80 ms RTT. With Unified CCE, the maximum latency between the Unified CCE components and Unified CM, or between the Unified CCE components themselves, is greater than 80 ms RTT.
For more details, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Similar to deployments with other Unified Communications components, contact center deployments require the configuration of Quality of Service (QoS) to prioritize time-sensitive or critical traffic. QoS marking for voice and voice signaling in a contact center environment is the same as with other Unified Communications deployments. Traffic specific to the contact center must be marked with specific QoS markings. For example, some of the traffic for the Unified CCE private network must be marked as AF31, while other traffic must be marked as AF11. The QoS marking recommendations and QoS design guidance are documented for each Unified Contact Center solution in their respective Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Call Admission Control
Similar to deployments with other Unified Communications components, contact center deployments require careful provisioning of call admission control. The same mechanisms described in the chapter on Bandwidth Management, also apply to contact center environments.
Voice traffic associated with silent monitoring and recording might not be accounted for in the call admission control calculation. For example, voice traffic from silent monitoring and recording by Unified CM (voice traffic forked at the phone) is properly accounted for, but voice traffic from desktop-based silent monitoring (desktop connected to the back of the agent IP phone) is not counted in call admission control calculations.
Call admission control for Mobile Agent and Unified CVP involves special considerations. For more details, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Integration with Unified CM
The following design considerations apply when integrating Cisco Unified Contact Center components with Unified CM:
- For administration and upgrade purposes, Cisco recommends separate Unified CM clusters for contact center and non-contact center deployments. If separate clusters are not possible, then Cisco recommends separate Unified CM subscriber nodes for contact center and non-contact center applications.
- With contact center deployments, Cisco recommends that you do not use a 2:1 redundancy scheme for Unified CM. Use 1:1 redundancy to provide higher resiliency and faster upgrades.
- The integration between Unified CM and Unified CCX, Unified IP IVR, or Unified CCE is done through JTAPI. The Unified CCX cluster connects to a primary CTI Manager and also has a backup connection to a secondary CTI Manager. With Unified CCE, the Agent PG connects to only one CTI Manager. The redundant Agent PG connects to the backup CTI Manager only. If the primary CTI Manager fails, the primary Agent PG will also fail and trigger the failover.
- A single PG can control and monitor agent phones on all Unified CM subscriber pairs in a centralized deployment, as illustrated in Figure 22-12.
- It is possible to integrate multiple Unified CCX deployments with a single Unified CM cluster.
For more details on Unified CM integration, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.
Figure 22-12 Deployment with One Agent PG and Four Unified CM Subscriber Pairs
Other Design Considerations for Contact Centers
The following additional design considerations apply in the situations indicated:
- Because Unified CVP allows queuing at the edge, deploying Unified CVP instead of Unified IP IVR could lower the bandwidth requirements for multisite deployments.
- Most of the Cisco Unified Contact Center products and components can be installed in a virtualized environment based on VMware.
- Media termination point (MTP) resources might be required in some scenarios. For example, with Mobile Agents and inbound calls through SIP trunks, MTPs are required for the associated CTI ports when RFC 2833 is negotiated. MTPs are also required in some scenarios with Unified CVP. With Unified CCX Extend and Connect, MTPs are required for the associated CTI Remote Device when RFC 2833 is negotiated.
- Transcoders might be required. For example, if phones in a WAN- connected location support only the G.729 codec but Unified CVP is configured for G.711 support, then Unified CM will engage transcoders. However, an inbound call that arrives from a gateway or Cisco Unified Border Element can start with G.711 at Unified CVP then later renegotiate to G.729 with the agents without the need for transcoders.
- Some third-party contact center products are also supported with Unified CM. The integration with Unified CM could be based on JTAPI and could use CTI ports for call treatment and queuing and CTI route points. To size Unified CM correctly, it is important to have a good understanding of the call flows and their impact on Unified CM. It is also important to understand how the redundancy is implemented and whether or not it impacts Unified CM or CTI scalability.
For more detailed design considerations, refer to the Cisco Unified Contact Center design guides available at http://www.cisco.com/go/ucsrnd.