Cisco Unity Fundamentals

Understanding Bridge Networking 307

Figure 10-29 Adding a New AMIS Subscriber

Understanding Bridge Networking

Bridge networking with Cisco Unity allows messages to be transferred between Cisco Unity

and Octel voice-mail servers within an Octel analog environment.

If you plan to implement Cisco Unity in an environment with Octel voice-mail servers, you

need to understand Bridge networking concepts and how it is implemented. This section

provides the information that you need to effectively and efficiently provide customers with

Bridge networking.

Remote Mailbox

Number of

Subscriber on the

Remote Voice

Messaging System

Subscriber

Type = AMIS

Location of

Remote AMIS

Messaging

System

308 Chapter 10: Unified Communications Networking

To benefit fully from this section, it is recommended that you have these prerequisite skills and

knowledge:

• Knowledge of Cisco Unity messaging call flow (see Chapter 1)

• Knowledge of how Cisco Unity handles calls (see Chapter 2)

• Understanding of the concepts presented in the “Cisco Unity Networking Fundamentals”

section of this chapter

Defining Bridge Networking

Cisco Unity Bridge is a gateway that runs on a server that allows Cisco Unity to communicate

with Octel nodes within an Octel analog network. On the Octel network, the Bridge appears as

another node on the network. This is similar to how Cisco Unity appears as a node on an AMIS

network. The Cisco Unity Bridge’s main function is to translate messages between two different

protocols. When the Bridge communicates with an Octel node, it actually places a call to the

Octel system, and then it uses the Octel analog protocol. When it communicates with the Cisco

Unity system Octel uses VPIM with proprietary extensions for added functionality. Because

VPIM uses TCP/IP to communicate, messaging between Cisco Unity and the Bridge can be

done over the Internet or a TCP/IP network using SMTP.

Bridge networking is a licensed feature of Cisco Unity and requires a separate Bridge server. If

you have multiple Cisco Unity servers in your organization, only one server needs to be

licensed for and designated as the Bridge server. For purposes of load balancing, you can add

more bridge servers. Bridge servers exist in a one-to-one relationship with Cisco Unity servers,

which means that if there are two Bridge servers, two Cisco Unity servers are required to be

configured for Bridge networking.

TIP To check whether your Cisco Unity server contains a license for Bridge networking, open the

license Manager by going to Start > Run > Programs > Unity > Licensing.

There, you will see all the features that are licensed, including the Bridge sessions. If the value

of Bridge sessions is greater than 1, then you are licensed for at least one session on the Cisco

Unity server.

You can find a list of supported Octel systems in the Cisco Unity Pre-Installation Guide found

at Cisco.com.

Understanding Bridge Networking 309

Figures 10-30 and 10-31 illustrate how the Cisco Unity Bridge can be implemented in an

enterprise’s messaging infrastructure.

Figure 10-30 illustrates using Cisco Unity Bridge with dual integration.

Figure 10-30 Cisco Unity with Dual Integration

When Cisco Unity is combined with Cisco Unity Bridge, it is a solution that is capable of

helping an organization manage the transition from legacy telephone equipment to a converged

IP network. In the diagram, Cisco Unity is integrated with two switches: a circuit-switched

(legacy) PBX and a Cisco CallManager. It can manage voice-mail accounts for subscribers with

either IP telephones or standard single-line extensions attached to a circuit-switched PBX. In

addition, Cisco Unity Bridge can send and receive voice-mail messages using Octel’s analog

messaging protocol through the analog lines that connect the legacy PBX and voice-mail

system. In this manner, an enterprise may maximize its return on investment on older telephone

equipment, while transitioning subscribers to an IP telephone network at a planned pace.

Figure 10-31 illustrates using Cisco Unity Bridge with Cisco CallManager.

IP Phones

Cisco Unity

Server

Cisco Unity

Bridge

PSTN

Legacy Phone

IP SCCP

(Skinny)

Workstation

with Microsoft Outlook

Cisco

CallManager

T-1 Line

SMDI Link

Analog Lines

Microsoft

Exchange

Message Store

Analog

Lines

Legacy PBX

Octel Voice Mail System

U

U

U

U

IVC