Cisco provides numerous Tcl applications for download from Cisco.com. The majority of these applications are focused on service provider needs, but several are useful to enterprise customers.
The auto attendant (AA) script is available for Survivable Remote Site Telephony (SRST) and Cisco CallManager Express (CME). This script provides basic call redirect based on caller input. When it is not possible or desirable to acquire a direct number for each phone at the location, the AA script allows you to use a single number, called the pilot number, to route calls. For example, a caller to the AA pilot number hears a customizable prompt to enter the desired extension or press 0 for the operator. When the caller enters a valid extension, the call is transferred. If the caller enters an invalid extension or does not enter any digits, the prompt is replayed. The steps for implementing the AA script are detailed in "Implementing the AA Tcl Script," later in this chapter.
If Cisco Unity Express (CUE) is installed in an SRST/CME router, you should use it to provide AA functionality.
Both SRST and CME have an AA script, but the scripts are not compatible. Make sure you download the correct script for your application.
The Basic-ACD (B-ACD) script provides automatic call distribution (ACD) support for basic call center or help desk-type applications. The B-ACD script works in conjunction with the CME AA. It provides an IVR, which prompts callers through a menu to determine into which queue they should be placed. Each queue has an associated AA. The AA uses an e-phone hunt group to route the call to the next available agent. The B-ACD also provides statistics about calls, such as how long a caller waited before his call was answered and how many calls were routed to voice mail because the configurable max call timer expired.
The Fax Detect script allows you to use a single number for both voice and fax calls. The script provides an option for prompting callers to press a particular key if they are placing a fax call. Alternatively, the script can detect that a call is a fax by listening for CalliNG (CNG) tones. When the script detects a fax call, it routes the call to the dial peer that is associated with the appropriate fax machine.
Fax Detect has several caveats, including a delay in call setup. Before you deploy the Fax Detect script, test it thoroughly to understand its possible side effects.
T.37 Store and Forward Fax
T.37 is a standard for converting faxes to Tagged Image File Format (TIFF) attachments that are sent via e-mail. T.37 Store and Forward Fax consists of an on-ramp and an off-ramp process. The on-ramp process converts an incoming fax to an e-mail message with a TIFF file attached. It can route an e-mail to an inbox or to an off-ramp process. The off-ramp process converts an e-mail that has a TIFF attachment back to a fax. You can load the on-ramp and off-ramp scripts on the same gateway or on different gateways.
Malicious Call ID
The Malicious Call ID (MCID) script works in conjunction with the MCID feature in Cisco CallManager 4.0. MCID allows a call recipient to press a programmable key on a Cisco IP phone if he receives a malicious call. This notifies the system administrator, flags the call in the call detail record (CDR) database, and instructs the gateway to send a message to the public switched telephone network (PSTN), allowing the service provider to take appropriate action. MCID is supported only on NET5 switches and must be enabled by the service provider.
Cisco Voice Portal
The Cisco Voice Portal (CVP) is a component of the Cisco customer contact product suite. CVP provides call treatment with self-service IVR options for both time-division multiplexing (TDM) and Voice over IP (VoIP) systems. Unlike the other sample applications listed here, CVP is not downloaded from Cisco.com.
CVP is included in this list because of the ability for a gateway to act as a remote site VoiceXML-controlled gateway for a centralized CVP server in a distributed contact center design. This is becoming a compelling network design for many Cisco customers. It allows the remote gateway to answer a call, play prompts, and collect the caller input. It keeps Real-Time Transport Protocol (RTP) streams off the network until the central ACD selects an agent to answer the call. If the caller uses the self-service features to complete his transaction and does not require an agent, the RTP call almost never uses bandwidth on the IP network.
Embedded Event Manager
The Cisco IOS Software Embedded Event Manager (EEM) is not a voice application; rather, it is a powerful tool that uses Tcl to greatly enhance network management. With EEM, you can define policies to take specific actions when Cisco IOS recognizes certain events. EEM uses event detectors to detect certain conditions in the device. EEM v2.2 has 15 event detectors; new event detectors are added with each version. The event detectors can either trigger an application policy included in EEM or can trigger custom Tcl scripts.
Part I: Voice Gateways and Gatekeepers
Gateways and Gatekeepers
Part II: Gateways
Media Gateway Control Protocol
Session Initiation Protocol
Connecting to the PSTN
Connecting to PBXs
Connecting to an IP WAN
Influencing Path Selection
Configuring Class of Restrictions
SRST and MGCP Gateway Fallback
Using Tcl Scripts and VoiceXML
Part III: Gatekeepers
Part IV: IP-to-IP Gateways
Cisco Multiservice IP-to-IP Gateway
Appendix A. Answers to Chapter-Ending Review Questions