Cisco Cisco Customer Response Solution Downloads Design Guide
C H A P T E R
6-1
Cisco Unified Contact Center Express Solution Reference Network Design, Release 4.1
6
Bandwidth, Security, and QoS Considerations
This chapter presents some design considerations for provisioning network bandwidth, providing
security and access to corporate data stores, and ensuring Quality of Service (QoS) for Unified CCX
applications.
security and access to corporate data stores, and ensuring Quality of Service (QoS) for Unified CCX
applications.
This chapter contains the following sections:
•
•
•
Estimating Bandwidth Consumption
Bandwidth plays a large role in deployments involving:
•
The centralized call processing model (Unified CCX at the central site)
•
Any call deployment model that uses call admission control or a gatekeeper
Remote Agent Traffic Profile
Remote Agent Traffic Profile Unified CCX signaling represents only a very small portion of control
traffic (Agent/Supervisor Desktop to and from the CRS Server) in the network. For information on TCP
ports and Differentiated Services Code Point (DSCP) marking for Unified CCX ICD and CTI traffic, see
the sections on
traffic (Agent/Supervisor Desktop to and from the CRS Server) in the network. For information on TCP
ports and Differentiated Services Code Point (DSCP) marking for Unified CCX ICD and CTI traffic, see
the sections on
, and
.
Bandwidth estimation becomes an issue when voice is included in the calculation. Because WAN links
are usually the lowest-speed circuits in an IP Telephony network, particular attention must be given to
reducing packet loss, delay, and jitter where voice traffic is sent across these links. G.729 is the preferred
codec for use over the WAN because the G.729 method for sampling audio introduces the least latency
(only 30 msecs) in addition to any other delays caused by the network.
are usually the lowest-speed circuits in an IP Telephony network, particular attention must be given to
reducing packet loss, delay, and jitter where voice traffic is sent across these links. G.729 is the preferred
codec for use over the WAN because the G.729 method for sampling audio introduces the least latency
(only 30 msecs) in addition to any other delays caused by the network.
Where voice is included in bandwidth, system architects should consider the following factors:
•
Total delay budget for latency (taking into account WAN latency, serialization delays for any local
area network traversed, and any forwarding latency present in the network devices). The generally
agreed-upon limit for total (one-way) latency for applications in a network is 150 milliseconds.
area network traversed, and any forwarding latency present in the network devices). The generally
agreed-upon limit for total (one-way) latency for applications in a network is 150 milliseconds.