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Networking Guide for Cisco Unity Release 5.x (With Microsoft Exchange)
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Chapter 7 VPIM Networking
VPIM Concepts and Definitions
How the Voice Connector Processes Outgoing VPIM Messages
When subscribers use the phone to address a message to a VPIM recipient, Cisco Unity constructs a To
address for the message in the form VPIM:<Location Dial ID>_<Remote Mailbox>. As with any other
message, Cisco Unity hands it off to Exchange for delivery. Because the message has a VPIM address
type, it is first passed to the Voice Connector for processing.
The Voice Connector does the following tasks:
• Converts the message from MAPI to MIME format.
• Formats the To address by using the domain name and prefix specified on the corresponding VPIM
delivery location page.
• Formats the From address by using the prefix from the corresponding VPIM delivery location page
and the domain name from the primary location page. (If your organization has more than one
Cisco Unity server networked together, the domain name is from the primary location of the
Cisco Unity server with which the sending subscriber is associated.)
• Checks the delivery location for the audio format conversion setting for outbound messages to
determine whether voice attachments should be converted to G.726 or remain in the format in which
they were recorded.
• Checks the delivery location to determine whether messages should be decrypted.
• Attaches the recorded voice name and/or vCard, if specified on the corresponding VPIM delivery
location page.
The newly formatted message is put in the SMTP pickup directory of the Windows server for delivery
to the VPIM-compliant voice messaging system.
How the Voice Connector Processes Incoming VPIM Messages
When the Transport Event Sink installation program is run, a transport event sink is registered with the
Windows SMTP server. A transport event sink is code that is activated through a defined trigger, such as
the receipt of a new message.
The VPIM Transport Event Sink monitors all incoming messages. Messages that have the content type
Multipart/Voice-Message and are addressed to the SMTP domain specified during the transport event
sink installation are readdressed to the Voice Connector by the VPIM Transport Event Sink.
When the Voice Connector receives the message, it first verifies that the message is from a domain
specified in a VPIM delivery location. If a VPIM delivery location with a matching domain name is not
found, the Voice Connector rejects the message and sends a non-delivery receipt (NDR) to the sender.
If a VPIM delivery location with a matching location is found, the Voice Connector does the following:
• Removes the phone prefixes from the To and From addresses, if prefixes are specified on the
corresponding VPIM delivery location page.
• Validates the recipient(s) of the message by looking up the extension(s) in Active Directory, and
formats the address(es).
• Converts the message from MIME to MAPI format.
• Converts voice attachments to the audio format specified on the corresponding VPIM delivery
location page.
• Checks the delivery location configuration to see whether automatic VPIM subscriber directory
updates are enabled. If so, the Voice Connector may attempt to generate a directory update message
as described in the “Automatic VPIM Subscriber Directory Updates” section on page 7-46.