Unified CCX Telephony and Media
The Unified CCX system uses a telephony resource called Computer Telephony Interface (CTI) ports to accept incoming calls and to place outbound calls. The Unified CCX system uses the following media resources to provide interactive services for calls:
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Unified CM Telephony—The Unified CCX Engine uses the Unified CM Telephony subsystem to send and receive calls from the Unified CM by interfacing with the CTI Manager through the Unified CM Telephony client.
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Cisco Media Termination (CMT)—The CMT channels provide media terminations in the Unified CCX for Unified CM Telephony Call Contacts. These channels enable the Unified CCX to play media to the connected party. DTMF digits are received out of band by the Unified CM Telephony subsystem.
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MRCP Automated Speech Recognition (MRCP ASR)—The ASR media resource allows callers to use speech to navigate menus and to provide other information to Unified CCX applications.
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MRCP Text-To-Speech (MRCP TTS)—The TTS media resource enables Unified CCX applications to play back documents to callers as speech.
Note
Media resources are licensed and sold as Unified IP IVR ports. Although you can provision more channels than you are licensed for, licensing is enforced at run-time. If more channels are provisioned than licensed, the system will not accept the extra calls, because doing so would violate your licensing agreements.
The Unified CCX system uses groups to share telephony and media resources among different applications:
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Call control groups allow you to control how the system uses CTI ports. For example, you can reserve more ports for higher-priority applications or provide access to fewer ports for applications with less traffic.
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Media resource groups allow you to share media resources among different applications. For example, you can share ASR media resource groups with applications that collect caller information and applications that transfer calls to specific extensions.
The Unified CCX system also uses triggers, which are specified signals that invoke application scripts in response to incoming contacts.
Media Termination Groups
Media termination groups are associated with CTI port groups.
![]() Note |
For Unified CM deployment, you can create and use additional CTI port groups as required. |
If a CTI port group is selected to support media termination and if the number of channels are identical to both groups, the CTI port group is automatically created in the background. This auto creation feature eliminates the manual CTI port group creation process.
If you choose to override media termination, the call control channel chooses the media termination automatically. If you want to select a new dialog group, you can have more than one media termination option. The options are used in the order that is displayed in the drop-down list.
Channels Required to Process Calls
Unified CCX needs two types of channels to process calls:
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A call control channel, which is provisioned through the Unified CM Telephony subsystem and corresponds to CTI port resources in Unified CM.
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A media channel, which is provisioned through either the CMT subsystem or the MRCP subsystem and corresponds to the kernel resources for handling the media voice path with the caller.
Note
MRCP channels also correspond to additional resources on the MRCP server for performing speech recognition.
Unified CCX needs access to a channel of each type to successfully process a call. However, the capabilities of the two channel types are not identical.
For example, consider a Unified CCX system provisioned with a single Unified CM Telephony call control channel (that is, a CTI port) and a single CMT channel. The system can handle one call at a time; when that call terminates, the system must reinitialize the channel resources before it can accept another call.
However, the time each channel takes to reinitialize is not equal—CMT channels take more time to reinitialize than CTI ports. For example:
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The Unified CM Telephony call control channel may take approximately 1 millisecond to reinitialize.
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The CMT channel may take approximately 200 milliseconds to reinitialize.
This example implies that the system will not be able to accept a new incoming call for 200 milliseconds after the first call terminates; although the Unified CM Telephony channel is available after one millisecond, the CMT channel is not and Unified CCX needs both channels to process a call.
Such a delay can become an issue when a Unified CCX system is experiencing a high load condition or needs to handle a burst of incoming calls. Consequently, CMT channels require a higher channel count provisioning.
![]() Tip |
To provision Unified CCX systems to handle burst calls equally among all required resources, you must configure approximately 10 percentage more CMT channels than CTI ports, and approximately 10 percentage more MRCP channels than ASR licenses. |
Provision Telephony and Media Resources
To provision telephony and media resources, complete the following tasks:
Procedure
Step 1 |
Provision the Unified CM Telephony subsystem. Unified CM Telephony subsystem controls telephony resources for Unified CCX system. |
Step 2 |
Provision the Cisco Media subsystem. Cisco Media subsystem controls CMT media resources for Unified CCX system. |
Step 3 |
Provision the MRCP ASR subsystem. MRCP ASR subsystem controls ASR media resources for Unified CCX system. |
Step 4 |
Provision the MRCP TTS subsystem. MRCP TTS subsystem controls TTS media resources for Unified CCX system. |