Cisco Cisco IP Contact Center Release 4.6.1 Leaflet
2-45
Cisco Unified Contact Center Enterprise 7.5 SRND
Chapter 2 Deployment Models
IPT: Clustering Over the WAN
Entire Central Site Loss
Loss of the entire central site is defined as the loss of all communications with a central site, as if the
site were switched off. This can result from natural disasters, power issues, major connectivity issues,
and human error, among other things. If a central site retains some but not all connectivity, it is not
considered a site loss but rather a partial connectivity loss, and this scenario is covered in subsequent
sections.
site were switched off. This can result from natural disasters, power issues, major connectivity issues,
and human error, among other things. If a central site retains some but not all connectivity, it is not
considered a site loss but rather a partial connectivity loss, and this scenario is covered in subsequent
sections.
When an entire central site has completely lost Unified CCE clustering over the WAN, Remote Agents
will fail-over properly to the redundant site. Failover times can range from 1 to 60 seconds for agents.
Variations are due to agent count, phone registration location, and agent desktop server used.
will fail-over properly to the redundant site. Failover times can range from 1 to 60 seconds for agents.
Variations are due to agent count, phone registration location, and agent desktop server used.
When using distributed VoiceXML gateways and Unified CVP, the gateways must fail-over from one
site to another if their primary site is lost. This failover takes approximately 30 seconds, and calls coming
into the remote gateways during those 30 seconds will be lost.
site to another if their primary site is lost. This failover takes approximately 30 seconds, and calls coming
into the remote gateways during those 30 seconds will be lost.
Private Connection Between Site 1 and Site 2
If the private connection between Unified ICM Central Controller sides A and B should fail, one Unified
ICM Router will go out-of-service and the other Unified ICM Router will then be running in simplex
mode until the link is reinstated. This situation will not cause any call loss or failure.
ICM Router will go out-of-service and the other Unified ICM Router will then be running in simplex
mode until the link is reinstated. This situation will not cause any call loss or failure.
If the private connection between PG side A and PG side B should fail, the non-active PG will go
out-of-service, causing the active PG to run in simplex mode until the link is reinstated. This situation
will not cause any call loss or failure.
out-of-service, causing the active PG to run in simplex mode until the link is reinstated. This situation
will not cause any call loss or failure.
When using a combined private link, Unified ICM Central Controller and PG private connections will
be lost if the link is lost. This will cause both components to switch to simplex mode as described above.
This situation will not cause any call loss or failure.
be lost if the link is lost. This will cause both components to switch to simplex mode as described above.
This situation will not cause any call loss or failure.
Connectivity to Central Site from Remote Agent Site
If connectivity to one of the central sites is lost from a Remote Agent site, all phones and agent desktops
will immediately switch to the second central site and begin processing calls. Failover typically takes
between 1 and 60 seconds.
will immediately switch to the second central site and begin processing calls. Failover typically takes
between 1 and 60 seconds.
Highly Available WAN Failure
By definition, a highly available (HA) WAN should not fail under normal circumstances. If the HA WAN
is dual-path and fully redundant, as it should be, a failure of this type would be highly unusual. This
section discusses what happens in this unlikely scenario.
is dual-path and fully redundant, as it should be, a failure of this type would be highly unusual. This
section discusses what happens in this unlikely scenario.
If the HA WAN is lost for any reason, the Unified CM cluster becomes split. The primary result from
this occurrence is that Unified ICM loses contact with half of the agent phones. Unified ICM is in
communication with only half of the cluster and cannot communicate with or see any phones registered
on the other half. This causes Unified ICM to immediately log out all agents with phones that are no
longer visible. These agents cannot log back in until the highly available WAN is restored or their phones
are forced to switch cluster sides.
this occurrence is that Unified ICM loses contact with half of the agent phones. Unified ICM is in
communication with only half of the cluster and cannot communicate with or see any phones registered
on the other half. This causes Unified ICM to immediately log out all agents with phones that are no
longer visible. These agents cannot log back in until the highly available WAN is restored or their phones
are forced to switch cluster sides.