238 Chapter 9: Cisco Unified Communications Integrations
Understanding the Attributes of Cisco Unified
Communications Integrations
Understanding the attributes of a communications integration will help you during installation
and while analyzing integration issues that may arise. This understanding will enable you to
save valuable time when troubleshooting these issues.
To fully benefit from this section, it is recommended that you have the following prerequisite
skills and knowledge (see Chapter 1, “Cisco Unified Communications System Fundamentals,
for a quick review of any of these topics):
Understand basic telephone system terminologies
Understand Cisco Unity standard features
Understand Cisco Unity basic call flow
Integrating Cisco Unity and CCM
Computer-based telephone systems are becoming more and more popular. Most of them
communicate via an Ethernet connection. This new method requires new ways of integrating
voice mail with them. Cisco Unity uses the Skinny Client Control Protocol (SCCP) to
communicate directly with Cisco CallManager. Because Cisco Unity and CCM are on separate
servers, each requires some information from the other to communicate. CCM, for example,
must know information such as the names of the voice-mail ports and the extensions that should
be assigned to the voice-mail ports. The Cisco Unity side requires information such as what the
IP addresses are of the CCMs that Cisco Unity will be servicing and what Message Waiting on
and off numbers are assigned in CCM. With each voice-mail port given a specific name by using
a number suffix incremented for each, Cisco Unity must also know what common prefix has
been assigned to the group of ports being configured.
You can configure Cisco Unity and CCM in many ways, depending on the customer’s
requirements and the site’s existing network topology.
The issues involved are normally focused on WAN deployments. Most LAN deployments are
very flexible because they have fewer bandwidth constraints. It is important to understand how
all the components interact to determine what works best for the customer. Figure 9-2 illustrates
a Cisco Unity and CCM integration.
Understanding the Attributes of Cisco Unified Communications Integrations 239
Figure 9-2 Cisco Unity and CCM Integration
Integrating PA and CCM
The information that passes between the Cisco PA and CCM is basically call information
carried as IP packets over a company’s LAN. The PA uses interceptor ports to identify the
telephone extensions that PA will intercept from CCM. You must configure these ports as
computer telephony integration (CTI) route points and translation patterns in CCM to identify
them in the PA server configuration. The CTI route point’s configuration allows PA to intercept
the call; the translation patterns allow calls to go through to the extension if the PA server is
unavailable.
Figure 9-3 illustrates the following steps to complete a Cisco PA and CCM integration:
1 A call arrives for an extension from the Public Switched Telephone Network (PSTN).
2 Because this extension has a PA interceptor port (CTI route point) configured for it, CCM
routes the call to PA.
3 PA retrieves the user information from the Lightweight Directory Access Protocol
(LDAP) directory and checks whether the user has any rules set.
4 In this example, the user has a rule set to have calls sent to a branch office where the user
is working. The call extends to a phone on the branch office.
IP Phones
Workstation
with Microsoft Outlook
MS Exchange
Message Store
U
U
Cisco Unity
Server
SCCP for
CCM
PSTN
Gateway
Cisco
CallManager
LAN
Switch

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