If your SIP deployment requires IPv6 addressing, you can configure Cisco Unified Communications Manager to support dual stack IPv4 and IPv6 addressing. By default, Cisco Unified Communications Manager is enabled for IPv4 addressing. At the
system level, you cannot configure Cisco Unified Communications Manager to support IPv6 only because the system must still interact with devices that
support IPv4 only. However, if you require IPv6 addressing, you can configure dual stack trunks and devices.
Dual Stack IPv6 at the System Level
When Cisco Unified Communications Manager is configured for dual stack addressing the system can set up calls for the following
All devices in the call support IPv4 only
All devices in the call support IPv6 only
All devices in the call run in dual-stack mode—In this scenario, the system determines the IP address
type by the configuration for the IP Addressing Mode Preference for Signaling setting for
signaling events and the IP Addressing Mode Preference for Media enterprise parameter for
One device supports IPv4 only and the other supports IPv6 only—In this scenario, Cisco
Unified Communications Manager inserts an MTP into the call path to translate the signaling
between the two addressing types.
Cisco Unified Communications Manager supports IPv6 addresses for SIP environments only. For H.323 deployments, the system inserts an MTP into
the call path so that the IPv4 and IPv6 devices can communicate.
Dual Stack IPv6 for Devices
At the device level you can configure many devices and media resources such as phones,
gateways, conference bridges can be configured to use IPv4 addressing only, IPv6 addressing only, or dual stack. You can configure the preferred addressing method both for signaling and for media events.
For SIP devices, you can also configure the Alternate Network Address Types (ANAT) feature allowing a registered SIP device
to have both an IPv4 and IPv6 address at the same time. The device can communicate using either
address type, thereby allowing the device to interoperate seamlessly in both IPv4 and IPv6 networks. You can enable ANAT for SIP devices by enabling ANAT in the SIP Profile that is assigned to the device.
Dual Stack IPv6 Prerequisites
Before you configure Cisco Unified Communications Manager with dual stack IPv6 support, you must configure the following network servers and devices to support IPv6. For details, refer to your device user documentation:
Provision a DHCP and DNS server with IPv6 support. The Cisco Network Registrar server supports IPv6 for DHCP and DNS.
Configure the IOS for network devices such as gateways, routers, and MTPs with IPv6 support.
Configure your TFTP server to run IPv6.
Dual Stack IPv6 Configuration Task Flow
Complete the following tasks to configure the system for dual stack IPv6.
You can configure the IP Addressing preference for individual trunks or SIP devices by configuring a Common Device Configuration that includes the IP address preferences and then applying that configuration to a trunk or device.
Configure the IP Address preference at the system level using clusterwide enterprise parameters. The setting applies to all SIP devices and trunks in the cluster unless an overriding Common Device Configuration is applied to a trunk or device.
Configure a Common Device Configuration with IP addressing preferences. You can apply the configuration to dual stack devices such SIP trunks, SIP phones, conference bridges, and transcoders.
The IP addressing preference settings in the Common Device Configuration override the clusterwide enterprise parameter settings for the devices that use the Common Device Configuration.
Addressing Preference for Cluster
Use this procedure
to use enterprise parameters to configure clusterwide IP addressing preferences
for dual stack IPv6. The system applies these settings to all SIP trunks and
devices unless an overriding Common Device Configuration is applied
to a specific trunk or device.
Unified CM Administration, choose
System > Enterprise
Set the value
Addressing Mode Preference for Media enterprise parameter to
Set the value
Addressing Mode Preference for Signaling enterprise parameter to
You can configure IP addressing preferences for individual devices by configuring a Common Device Configuration with the preference settings. You can apply the Common Device Configuration to SIP devices that support IPv6 addressing such as trunks, phones, conferences bridges, and transcoders.
The IP address preferences in a common Device Configuration override the clusterwide enterprise parameter settings for the devices that use that Common Device Configuration.
From Cisco Unified CM Administration, choose Device > Device Settings > Common Device Configuration.
Click Add New.
Configure the fields in the Common Device Configuration window. For help with the fields and their settings, refer to the online help.
For SIP trunks or SCCP phones, choose a value for the IP Addressing Mode drop-down list box:
IPv4 Only—The device uses only an IPv4 address for media and signaling.
IPv6 Only—The device uses only an IPv6 address for media and signaling.
IPv4 and IPv6 (Default)—The device is a dual-stack device and uses whichever IP address type is available. If both IP address types are configured on the device, for signaling the device uses the IP Addressing Mode Preference for Signaling setting and for media the device uses the IP Addressing Mode Preference for Media enterprise parameter setting.
For dual stack phones or trunks, configure an IP addressing preference for the IP Addressing Mode for Signaling drop-down list box:
IPv4—The dual stack device prefers IPv4 address for signaling.
IPv6—The dual stack device prefers IPv6 address for signaling.
Use System Default—The device uses the setting for the IP Addressing Mode Preference for Signaling enterprise parameter.