Cisco Unified Contact Center Enterprise Solution Reference ...

Chapter 11 Bandwidth Provisioning and QoS Considerations
Traffic Flow
Public Network Traffic Flow
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Figure 11-2 Example of Different Cisco Unified CallManager Clusters
IPT Cluster IPCC Cluster
M M
IP IP
RSVP Agent
RSVP Agent
IP IP
Unified CCE Network Architecture Overview
For more information on CallManager 5.0 RSVP please refer to the Cisco Unified Communications
SRND Based on Cisco Unified CallManager 5.0 at this URL: http://www.cisco.com/go/srnd
This section briefly describes the traffic flows for the public and private networks.
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The active PG continuously updates the Central Controller call routers with state information related to
agents, calls, queues, and so forth, at the respective call center sites. This type of PG-to-Central
Controller traffic is real-time traffic. The PGs also send up historical data each half hour on the half hour.
The historical data is low-priority, but it must complete its journey to the central site within the half hour
(to get ready for the next half hour of data).
When a PG starts, its configuration data is supplied from the central site so that it can know which agents,
trunks, and so forth, it has to monitor. This configuration download can be a significant network
bandwidth transient.
In summary, traffic flows from PG to Central Controller can be classified into the following distinct
flows:
High-priority traffic — Includes routing and Device Management Protocol (DMP) control traffic. It
is sent in TCP with the public high-priority IP address.
Heartbeat traffic — UDP messages with the public high-priority IP address and in the port range of
39500 to 39999. Heartbeats are transmitted at 400-ms intervals bidirectionally between the PG and
the Central Controller. In Unified ICM Release 7.0, the UDP heartbeat is replaced with TCP
keep-alive if QoS is enabled on the public network interface through the Unified ICM setup.
Medium-priority traffic — Includes real-time traffic and configuration requests from the PG to the
Central Controller. The medium-priority traffic is sent in TCP with the public high-priority IP
address.
Cisco Unified Contact Center Enterprise 7.x SRND
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