Configuration Limits and Scalability Constraints for Non-Reference Designs
The following tables specify the configuration limits and scalability constraints for the Unified ICM/CCE products. These configuration limits are part of the Unified ICM/CCE product design constraints and were used for system sizing characteristics as tested by Cisco. Most of these system parameters (or combinations of these system parameters) form contribution factors that affect system capacity.
These limits apply to Non-Reference Designs, only. Do not use these limits to size a Reference Design solution. If you are not using the standard three coresident PG layout of one Agent PG, one VRU PG, and one MR PG, your design is a Non-Reference Design. The higher configuration limits that are listed for Reference Designs do not apply without the standard PG layout.
When you design your contact center, ensure that your design is deployed within these limits. (See the comments in the following table for more information.) Consult Cisco if you have special configuration requirements that might exceed specific parameters.
This information serves as a quick reference. Check the Virtualization for Unified Contact Center Enterprise at http://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/uc_system/virtualization/virtualization-unified-contact-center-enterprise.html and the Contact Center Enterprise Compatibility Matrix at https://www.cisco.com/c/en/us/support/customer-collaboration/unified-contact-center-enterprise/products-device-support-tables-list.html for more information on system constraints.
The compatibility matrix specifies all supported configurations and versions for Cisco Unified Contact Center Enterprise Release 10.0 . The information in the compatibility matrix supersedes compatibility information in any other Cisco Unified Contact Center Enterprise documentation. If a configuration or version is not stated in the compatibility matrix, that configuration or version is not supported.
The check mark in the table indicates that a given parameter is applicable to the indicated Unified ICM/CCE product edition. See the notes at the end of this table.
|Maximum Limit||Limit Value||Applies to||Comments|
|<=450 agents (Unified CCE only)||>450 - <=12,000 agents||Unified CCE||Unified ICM|
Includes setup, config, and scripting users.
|ECC (Extended Context Call) and User variables size (bytes)||2000||2000||
Unified CVP and Outbound Option rely on a subset of this maximum limit for integration with Unified ICM.
The maximum that is indicated is independent from the number of ECC and user variables used, with each representing approximately 50-bytes extra storage per record. The maximum includes both persistent and nonpersistent variables.
|Number of Peripheral Variables (Call Variables)||10||10|
|Peripheral Variable length (characters)||40||40||40 characters, excluding terminating NULL.|
|VRU PIMs on each VRU PG||N/A||10||
Each CVP supports up to 3000 ports and 15 CPS, and each VRU PG can support a maximum of 12000 ports.
Up to 10 VRU PIMs per VRU PG can be supported as long as the total ports on the VRU PG are less than 12000, and the total CPS across all the VRU PIMs is less than 60 CPS.
|Maximum CPS per VRU PIM||N/A||15||Maximum CPS per VRU PG is 60.|
|VRU PIMs on each Generic PG||2||4||
A Generic PG with Unified CM (CUCM) PIM only supports 1000 Ports total.
|VRU PIMs on each System PG||N/A||5||—||IP-IVR PIMs only.|
|TDM PIMs on each PG||N/A||5||—||
Multiple PIMs on a PG affect performance. Compared to a single PIM on each PG, multiple PIMs lower the total number of agents, VRU ports, and supported call volume. There is a maximum of one PIM on each TDM PG with CTI OS coresident.
|MR PIMs on each MR PG||1||2|
|Maximum Number of PGs for each CUCM Cluster||4||4|
|Duplex PGs on each ICM instance||1||150||For deployments with <= 450 agents and Cisco Outbound Option, there is another MR PG. See UCM limit above.|
|PIMs on each system (total)||4||150||One agent PIM, two VRU PIMs, and one MR PIM (applies to >= 450 agents only).|
|Configured agents on each system (total)||N/A||65,000||—|
|Configured agents on each system (total)||3000||76,000||—|
|Configured agents on each peripheral||3000||
|Skill groups on each peripheral gateway||1500||4000||Configuration of precision queues creates a skill group per agent PG which counts toward the supported number of skill groups on each PG.|
|Skill groups on each system||1500||27,000||Configuration of precision queues creates a skill group per agent PG which counts toward the supported number of skill groups on each system.|
|CTI OS on each Agent PIM||1||1|
|Provisioning operations on each hour||30||120||For Configuration Manager, CCMP or AAS – maximum number of save operations across all ADSs in the solution in a 1-hour period. 200 changes per provisioning operation.|
Maximum agents tracked in Agent State Trace
For more information on Agent State Trace, see the Configuration Guide for Cisco Unified ICM/Contact Center Enterprise at http://www.cisco.com/c/en/us/support/customer-collaboration/unified-contact-center-enterprise/products-installation-and-configuration-guides-list.html
|SIP dialer ports on each dialer||N/A||1500||—||This limit assumes that the model is distributed, numbers vary based on deployment.|
|SIP dialers on each PG pair (Side A + Side B)||N/A||1||—||Only one dialer type can be installed per PG.|
|SIP dialer Ports on each server (total)||N/A||1500||—||—||In multi-instance deployment.|
|Dialer ports on each system (total)||N/A||4000||—|
|Dialers on each system (total)||N/A||32||—|
|Campaigns on each system||N/A||600||—||
Sizing is required. Smaller deployments cannot support the full 600 campaigns.
|Campaigns skill groups on each system||N/A||100||—||Total skill groups from all campaigns.|
|Campaign skill groups on each campaign||N/A||20||—||Limitation on skill groups for any given campaign (as long as the maximum 100 campaign skill groups per system not exceeded).|
|Dialed numbers on each system||1500||240,000|
|Labels configured on each system||500||
100,000 for up to 4000 agents
160,000 for up to 12,000 agents
|Call type skill groups on each interval||1000||30,000||Total call type skill group records.|
|Configured call types||500||10,000||Total call types configured.|
|Active call types||250||8000|
|Precision Routing (PR) Attributes on each system||N/A||10,000||—|
|PR Attributes for each Agent||N/A||50||—|
|PR Precision Queues (PQ) on each system||N/A||4000||—|
|PR PQ Steps on each system||N/A||10,000||—|
|PR Terms for each PQ Step||N/A||10||—|
|PR Steps for each PQ||N/A||10||—|
|PR Unique attributes for each PQ||N/A||10||—|
Unique skill groups and PQs in a supervisor team
Deployments close to the maximum number of configured agents on a system can show performance degradation and failed call routing, especially if contending capacity limitations also approach maximum thresholds. Expert assistance from partner or professional services is necessary for capacity-related system planning. Parameters that most impact performance with large numbers of configured agents includes total number of system peripherals, routes, number of active agents, and overall call load. The points at highest risk for degradation are busy hours and the half-hour update period, during which the PG sends report data to the Central Controller. System administrators can lessen the impact of these issues by purging unused configured agents, retiring inactive peripherals, and maintaining systems at current maintenance release levels.
Unified CCE Solution
Additional Sizing Factors
Many variables in the Unified CCE configuration and deployment options can affect the server requirements and capacities. This section describes the major sizing variables and how they affect the capacity of the various Unified CCE components.
Busy Hour Call Attempts (BHCA)
The number of calls attempted during a busy hour is an important metric. As BHCA increases, there is an increase in the load on all Unified CCE components, most notably on Unified CM, Unified IP IVR, and the Unified CM PG. The capacity numbers for agents assume up to 30 calls per hour per agent. If a deployment requires more than 30 calls per hour per agent, it decreases the maximum number of supported agents for the agent PG. Handle such occurrences on a case-by-case basis.
The number of agents is another important metric that impacts the performance of most Unified CCE server components, including Unified CM clusters.
Average Skill Groups or Precision Queues Per Agent
The number of skill groups or precision queues per agent (which is independent of the total number of skills per system) significantly affects the following:
CTI OS servers
Limit the number of skill groups and precision queues per agent to 5 or fewer, when possible. Periodically remove unused skill groups or precision queues so that they do not affect the system's performance. You can also manage the effects on the CTI OS Server by increasing the value for the frequency of statistical updates.
The Finesse server does not display statistics for unused skill groups. Therefore, the number of skill groups that are assigned to agents affects the performance of the Finesse server more than the total number of skill groups configured.
Queue (skill group) statistics are updated on the Finesse Desktop at 10-second intervals. The Finesse Desktop also supports a fixed number of queue statistics fields. These fields cannot be changed.
The first table shows examples of the number of skill groups or precision queues (PQ) per agent affecting the capacity of the Unified CCE system. The table shows the capacity for each CTI OS instance. The Finesse server supports the same number of agents and skill groups as CTI OS.
Unified CCE supports a maximum of 50 unique skill groups across all agents on a supervisor’s team, including the supervisor’s own skill groups. If this number is exceeded, all skill groups monitored by the supervisor still appear on the supervisor desktop. However, exceeding this number can cause performance issues and is not supported.
Each precision queue that you configure creates a skill group per Agent PG and counts toward the supported number of skill groups per PG. The skill groups are created in the same Media Routing Domain as the precision queue.
The numbers in this table are subject to specific hardware and software requirements.
|Avg Configured PQ or SG for each Agent||System||Generic PG Limits|
|Max Concurrent Agent for each System||Max Concurrent Agent for each PG||Max Configured PQ or SG for each PG||Max Configured VRU Ports for each PG||Max Configured VRU PIMs for each PG|
CTI OS monitor mode applications are supported only at 20 or lower skill groups per agent.
Supervisors and Teams
The number of supervisors and team members can also be a factor impacting the CTI OS Server performance. Distribute your agents and supervisors across multiple teams and have each supervisor monitor only a few agents.
Supervisors can monitor only agents within their own team, and all of the agents must be configured on the same peripheral.
You can add a maximum of 50 agents per team. You can add a maximum of ten supervisors per team.
A Unified CCE system can support a maximum of 50 agents per supervisor with the assumptions below. If a particular environment requires more than 50 agents per supervisor, then use the following formula to ensure that there is no impact to the CTI OS Server and Supervisor desktop. The most important factor in this calculation is the number of updates per second.
X = (Y * (N + 1) / R) + ((Z * N * A) / 3600), rounded up to the next integer
X = Number of updates per second received by the CTI OS Supervisor desktop.
Y = Weighted Average of Number of Skill Groups or Precision Queues per Agents. For example, if total of 10 agents have the
following skill group distribution: 9 have 1 skill group and 1 agent has 12 Skill Groups. The number of skills per agent ('Y')
is, Y = 90% * 1 + 10% * 12 = 2.1.
(The number of configured statistics in the CTI OS server is 17.)
Z = Calls per hour per agent.
A = Number of agent states. (Varies based on call flow; average = 10.)
N = Number of agents per supervisor.
R = The skill group or precision queue refresh rate configured on the CTI OS Server. (Default = 10 seconds.)
(Y * (N + 1) / R) = Number of updates per second, based on skill groups.
(Z * N * A) / 3600 = Number of updates per second, based on calls.
The CTI OS Supervisor desktop is not impacted as long as there are fewer than 31 updates per second. This threshold value is derived by using the above formula to calculate the update rate for 50 agents per supervisor (N = 50), as follows:
X = (5 * (50 + 1) / 10) + ((30 * 50 * 10) / 3600) = 25.5 + 5 = 31 updates per second
The maximum number of agents per supervisor must not exceed 200 for any given configuration, still holding updates per second to a maximum of 31 with the above formula.
CTI OS Monitor Mode Applications
A CTI OS Monitor Mode application can affect the performance of the CTI OS Server. CTI OS supports only two such applications per server pair. Depending on the filter specified, the impact on the CPU utilization might degrade the performance of the Agent PG.
Unified CM Silent Monitor
Each silently monitored call adds more processing for the PG and Unified CM. Each silently monitored call is equivalent to two unmonitored calls to an agent. Make sure that the percentage of the monitored calls is within the capabilities of PG scalability.
CTI OS Skill Group Statistics Refresh Rate
The skill group statistics refresh rate can also affect the performance of CTI OS Server. Cisco requires that you do not lower the refresh rate below the default value of 10 seconds.
The call type is also an important metric that affects the performance of most Unified CCE server components. An increase in the number of transfers and conferences increase the load on the system which decreases the total capacity.
The Unified IP IVR and Unified Customer Voice Portal (CVP) place calls in a queue and play announcements until an agent answers the call. For sizing purposes, it is important to know whether:
The VRU will handle all calls initially (call treatment), and direct the callers to agents after a short queuing period.
The agents will handle calls immediately, and the VRU queues only unanswered calls when all agents are busy.
The answer to this question determines very different VRU sizing requirements and affects the performance of the Call Router/Logger and Voice Response Unit (VRU) PG.
Translation Route Pool
Sizing the translation route pool depends on the expected call arrival rate. Use the following formula to size the translation route pool:
Translation route pool = 20 * (Calls per second)
This calculation is specific to Unified CCE . For more general Unified ICM deployments, consult your Cisco Account Team or Partner.
UCCE Script Complexity
As the complexity and/or number of UCCE scripts increase, the processor and memory overhead on the Call Router and VRU PG increases significantly. The delay time between replaying RunExternalScript also has an impact.
Real-time reporting can have a significant effect on Logger and Rogger processing due to database access. A separate VM is required for an Administration & Data Server to off-load reporting overhead from the Logger and Rogger.
VRU Script Complexity
As VRU script complexity increases with features such as database queries, the load placed on the IP IVR Server and the Router also increases. There is no good rule or benchmark to characterize the Unified IP IVR performance when used for complex scripting, complex database queries, or transaction-based usage. Test complex VRU configurations in a lab or pilot deployment to determine the response time of database queries under various BHCA and how they affect the processor and memory for the VRU server, PG, and Router.
Unified IP IVR Self-Service Applications
In deployments where the Unified IP IVR is also used for self-service applications, the self-service applications are in addition to the Unified CCE load. Factor self-service applications into the sizing requirements as stated in the sizing tables above.
Third-Party Database and Cisco Resource Manager Connectivity
Carefully examine connectivity of any Unified CCE solution component to an external device and/or software to determine the overall effect on the solution. Cisco Unified CCE solutions are flexible and customizable, but they can also be complex. Contact centers are often mission-critical, revenue-generating, and customer-facing operations. Therefore, engage a Cisco Partner (or Cisco Advanced Services) with the appropriate experience and certifications to help you design your Unified CCE solution.
Expanded Call Context (ECC)
The ECC usage impacts PG, Router, Logger, and network bandwidth. There are many ways that ECC can be configured and used. The capacity impact varies based on ECC configuration, handled on a case-by-case basis.