5-39
Networking Guide for Cisco Unity Release 5.x (With Microsoft Exchange)
OL-13844-01
Chapter 5 AMIS Networking
AMIS Concepts and Definitions
Figure 5-1 AMIS Bridgehead Configuration
Design Considerations
Because AMIS calls are placed and answered on the Cisco Unity server on which the AMIS delivery
locations were created, you can configure your Cisco Unity servers as needed to handle AMIS traffic.
You can set up a bridgehead topology by designating one Cisco Unity server in the network to
handle sending and receiving AMIS calls. See Figure 5-1.
Recall that the dialout for an outbound AMIS message originates from the Cisco Unity server on
which an AMIS delivery location was created. If the AMIS traffic is too heavy for one Cisco Unity
server to handle, you can balance the load by setting up multiple AMIS bridgehead servers. In this
case, you need to determine which AMIS delivery locations and AMIS subscribers to create on each
of the Cisco Unity servers, and keep a record of the mapping.
For example, assume that there are two AMIS bridgehead servers, Bridgehead A and Bridgehead B,
and there are four AMIS delivery locations called London, Paris, Goose Creek, and Monks Corner.
You anticipate that message delivery to the London and Paris delivery locations will be heavy, and
that message delivery to the Goose Creek and Monks Corner delivery locations will not be as heavy.
You can balance the load by creating the London and Goose Creek delivery locations on
Bridgehead A, and create the Paris and Monks Corner delivery locations on Bridgehead B. This
ensures that the AMIS traffic for the two heavy AMIS locations is split up between the two
bridgehead servers, rather than one trying to deliver all of the messages by itself.
For organizations with Cisco Unity servers deployed in different areas around the country or the
world, it may be possible to set up a least-cost-routing topology to minimize or eliminate long
distance phone charges related to AMIS transmissions.
For example, assume there are Cisco Unity servers in Chicago and in New York, and that there is
also another voice messaging system in New York to which subscribers in Chicago want to send
messages. To avoid long distance phone charges when subscribers in Chicago send messages to
Unity 1
Remote voice messaging
system (RVMS)
Directory
Unity 2
Exchange
server 2
Exchange
server 1
PSTN
69378
Unity 3
Voice connector
UAmis_Unity2 mailbox
V