Cisco Cisco Unified IP Interactive Voice Response (IVR) 8.0(1) Release Note
7-13
Cisco Unified Contact Center Express Solution Reference Network Design
Chapter 7 Bandwidth, Security, and QoS Considerations
QoS and Call Admission Control
QoS and Call Admission Control
Quality of Service (QoS) becomes an issue when more voice and application-related traffic is added to
an already growing amount of data traffic on your network. Accordingly, Cisco Unified CCX and
time-sensitive traffic such as voice need higher QoS guarantees than less time-sensitive traffic such as
file transfers or emails (particularly if you are using a converged network).
an already growing amount of data traffic on your network. Accordingly, Cisco Unified CCX and
time-sensitive traffic such as voice need higher QoS guarantees than less time-sensitive traffic such as
file transfers or emails (particularly if you are using a converged network).
QoS should be used to assign different qualities to data streams to preserve Cisco Unified CCX
mission-critical and voice traffic. The following are some examples of available QoS mechanisms:
mission-critical and voice traffic. The following are some examples of available QoS mechanisms:
•
Packet classification and usage policies applied at the edge of the network, such as Policy Based
Routing (PBR) and Committed Access Rate (CAR).
Routing (PBR) and Committed Access Rate (CAR).
•
End-to-end queuing mechanisms, such as Low Latency Queuing (LLQ). Because voice is
susceptible to increased latency and jitter on low-speed links, Link Fragmentation and Interleaving
(LFI) can also be used to reduce delay and jitter by subdividing large datagrams and interleaving
low-delay traffic with the resulting smaller packets.
susceptible to increased latency and jitter on low-speed links, Link Fragmentation and Interleaving
(LFI) can also be used to reduce delay and jitter by subdividing large datagrams and interleaving
low-delay traffic with the resulting smaller packets.
•
Scheduling mechanisms such as Traffic Shaping to optimize bandwidth utilization on output links.
Classifying Cisco Unified CCX and Application-Related Traffic
and the following section list TCP ports and DSCP markings for use in prioritizing Cisco
Unified CCX and Cisco Unified CM mission-critical CTI traffic. The DSCP Markings for call signaling
traffic between Cisco Unified CCX and Cisco Unified Communication manager and for voice traffic
played from the Unified CCX server are set by default according to the recommended traffic
classification guidelines documented in Cisco Unified Communications System Design Guidance,
available at:
traffic between Cisco Unified CCX and Cisco Unified Communication manager and for voice traffic
played from the Unified CCX server are set by default according to the recommended traffic
classification guidelines documented in Cisco Unified Communications System Design Guidance,
available at:
.
Cisco Unified CCX does not mark any network traffic other than those mentioned above.
The performance criteria used in classifying such traffic includes:
•
No packet drops on the outbound or inbound interface of the WAN edge router
•
Voice (G.729) loss under 1%
•
One-way voice delay under 150 msecs
A detailed description of QoS is not within the scope of this design guide. For QoS design
recommendations, refer the Quality of Service design guide available at:
recommendations, refer the Quality of Service design guide available at:
Table 7-10
QoS Classifications for Cisco Unified CCX Interfaces
Cisco Unified CCX Component
Interface /
Protocol
Protocol
Port
DSCP Marking
CTI messaging between Cisco Unified CCX Cisco Unified CM
Telephony subsystem and Cisco Unified CM (both directions)
Telephony subsystem and Cisco Unified CM (both directions)
CTIQBE
TCP 2748
CS3
HTTP (Cisco Unified CCX administration page and IPPA interface)
HTTP
TCP 6293
AF21
AXL to Cisco Unified CM for User configuration and authentication
(SSL)
(SSL)
SOAP AXL
TCP 8433
AF21
E-mail
SMTP
TCP 25
CS0
Messaging data between Cisco Unified CCX and Cisco Agent Desktop CTI
TCP 42027
CS3
IMAP
1
TCP 143
CS0