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Networking Guide for Cisco Unity Release 5.x (With Microsoft Exchange)
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Chapter 8 Using VPIM for Networking with Cisco Unity Express or Other Cisco Unity Systems
Messaging Between Cisco Unity Servers in Different Directories
Figure 8-2 VPIM Subscribers That Correspond to Remote Cisco Unity Subscribers
Audio Format Conversion Settings
When using VPIM Networking for messaging between Cisco Unity servers in different directories, the
Audio Format Conversion Settings for outbound and incoming messages need to be coordinated on the
Cisco Unity servers to avoid unnecessary conversions. When making decisions about the conversion
settings:
Consider the network bandwidth between the local and remote Cisco Unity servers, and the volume
of message traffic.
Determine which codecs are installed or will need to be installed on subscriber workstations and
Cisco Unity servers in the local and remote sites.
The following examples show a few of the combinations of the Audio Format Conversion Settings to
give you an idea of the options.

Example 1: Both Cisco Unity Servers Use G.729a for Recording and Storage

As shown in Figure 8-3, both the local and remote Cisco Unity servers record messages by using the
G.729a codec. At 8 Kbps, the G.729a codec is recommended for use when network bandwidth is an
issue. Because of theses considerations, no audio format conversions are needed when messages are
transmitted between the servers.

VPIM Subscriber

Kelly Bader
Extension: 5678
Remote Mailbox Number: 5678

Subscriber

Kelly Bader
Extension: 5678

VPIM Subscriber

Avery Hughes
Extension: 1234
Remote Mailbox Number: 1234

Subscriber

Avery Hughes
Extension: 1234
ParisUnity
NewYorkUnity
Dial ID: 444
Domain Name: ny.cisco.com
Primary Location
Dial ID: 333
Domain Name: paris.cisco.com
Primary Location
Dial ID: 333
Domain Name: paris.cisco.com
VPIM Delivery Location
Dial ID: 444
Domain Name: ny.cisco.com
VPIM Delivery Location
Internet
104948