This document describes how to properly configure Cisco Unity to work
with two Network Interface Cards (NICs) when Cisco Unity is integrated with a
CallManager. Voice messaging does not work as expected if it is not properly
There are no specific requirements for this document.
This document applies to all versions of Cisco Unity integrated with a
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
Many enterprise customers who source their own hardware purchase a
platform that has two NICs. If these NICs are not configured properly, voice
messaging does not work correctly, and you experience problems such as one-way
audio or a Message Waiting Indicator (MWI) malfunction. This document indicates
the supported configuration for dual NICs.
If you configure dual NICs for active-active load sharing, which means
that 50 percent of the traffic is handled by each NIC, one-way audio and MWI
problems can result. This setup is currently not supported on
a Cisco Unity server.
These factors can cause dual NICs to result in one-way audio during
call processing with a Cisco CallManager integration (using Skinny
With a Skinny integration, you have to send your IP address to the
other side of the call.
You determine your IP address by repeating through the NICs and
returning the IP address of the first NIC you find.
In a dual NIC configuration, you can choose the IP address of the
wrong NIC, which causes the one-way audio
There are two supported configurations for installation of Cisco Unity
on a platform with two NICs:
Disable one of the NICs.
Configure the NICs in an active-passive
Note: The IBM Cisco Media Convergence Server (MCS) servers cannot use the
MCS Network Teaming Driver that is included with the Hewlett-Packard
Cisco Unity does support dual NICs configured in an active-passive
manner for fault tolerance. In this NIC configuration, the primary (active) NIC
handles 100 percent of the traffic. Only in the event that it goes down, does
the secondary NIC become active and handle 100 percent of the traffic.
Therefore, only one IP address and one network (no subnets with each NIC on a
different subnet) is supported.
Note: The second interface cannot be configured with a different IP address
to be used as a management interface for Terminal Services.
To confirm that the NICs are configured correctly, perform these
Ensure that both NICs are set up for either adapter fault tolerant
mode (AFT) or for network fault tolerant (NFT). For more information about how
to do this, refer to the documentation provided by the NIC manufacturer or
If an MCS-7825H, MCS-7835H, or MCS-7845H server is configured, use
the network teams property sheet of the Compaq Network Teaming and
Configuration Utility (CPQNTAC, also known as NCU) in order to configure NFT
Note: Using the Remote Deployment Utility (RDU), the CPQNTAC utility
can be installed from the Hewlett-Packard SmartStart disc that was shipped with
If an IBM MCS-7815I, MCS-7855I, or MCS-7865I server is configured,
use the Advanced Control Suite of the Broadcom NetXtreme Ethernet utilities to
configure AFT teaming.
For the MCS-7835I and MCS-7845I servers, use the teaming wizard on
the Advanced tab of the Intel PROSet II Ethernet utilities to configure AFT
Restart the Cisco Unity server for any changes to take effect.