Achieving Unified CCE system security requires an effective security policy that accurately defines access, connection requirements, and systems management within your contact center. A good security policy enables you to use many state-of-the-art Cisco technologies to protect your data center resources from internal and external threats. Security measures ensure data privacy, integrity, and system availability.
The security considerations for Unified CCE at a high level are similar to the considerations for the other applications in a Cisco Unified Communications solution. Deployments of Unified CCE vary greatly and often call
for complex network designs. These deployments require competence in Layer 2 and Layer 3 networking as well as voice, VPN, QoS, Microsoft Windows Active Directory, and other networking issues. This chapter provides some guidance that touches on these areas. But, this chapter is not an
all-inclusive guide for deploying a secure Unified CCE network.
Along with the Unified Communications Security Solution portal, use other Cisco solution reference network design guides (SRNDs) in addition to this document to answer many design and deployment
questions. These documents provide information on properly building a network infrastructure for Cisco Unified Communications. In particular, consult the following relevant documents about security and Cisco Unified Communications:
Cisco Unified Communications SRND Based on Cisco Unified Communications Manager
Data Center Networking: Server Farm Security SRNDv2
Site-to-Site IPSec VPN SRND
Voice and Video Enabled IPSec VPN (V3PN) SRND
Business Ready Teleworker SRND
Updates and additions to these documents are posted periodically, so visit the SRND web site frequently.
This chapter provides limited guidance on the intricacies of designing and deploying a Windows Active Directory. More information is available from Microsoft on the following topics:
Designing a new Active Directory logical structure
Deploying Active Directory for the first time
Upgrading an existing
Windows environment to Windows Server 2008 R2 Active Directory
Restructuring your current environment to a Windows Active Directory environment
In particular, see the Designing and Deploying Directory and Security Services section of the Microsoft Windows Server 2008R2 Deployment Kit. That section
can assist you in meeting all the Active Directory design and deployment goals for your organization. This development kit and its related documentation are available from
An adequately secure Unified CCE deployment requires a multilayered approach to protecting systems and networks from targeted attacks and the propagation of viruses, among other threats. The goal of this chapter is to stress the various areas pertinent to securing a Unified CCE
deployment, but it does not delve into the details of each area. Specific details can be found in the relevant product documentation.
Implement the following security layers and establish policies around them:
Physical Security You must ensure that the servers hosting the Cisco contact center applications are physically secure. They must be located in data centers to which only authorized personnel have access. The cabling plant, routers, and switches also have controlled access.
Implementing a strong physical-layer network security plan also includes utilizing such things as port security on data switches.
Perimeter Security While this document does not delve into the details on how to design and deploy a secure data network, it does provide references to resources that can aid in establishing an effective secure environment for your contact center applications.
Data Security To ensure an increased level of protection from eavesdropping for customer-sensitive information, Unified CCE provides support for Transport Layer Security (TLS) on the CTI OS and Cisco Agent Desktops. It also supports IPSec to secure communication channels
Host-Based Firewall Users wishing to take advantage of the Windows Firewall to protect from malicious users and programs that use unsolicited incoming traffic to attack servers can use the Windows Firewall Configuration Utility on VMs or the Agent Desktop Installers to
integrate with the firewall component of Windows Server 2008 R2, and Windows XP SP3, respectively.
Virus Protection All VMs must be running antivirus applications with the latest virus definition files (scheduled for daily updates). The Compatibility Matrix for Unified CCE contains a list of all the tested and supported antivirus applications.
Patch Management A system is typically not connected to a live network until all security updates have been applied. It is important for all hosts to be kept up-to-date with Microsoft (Windows, SQL Server, Internet Explorer, and so forth) and other third-party security
For most of these security layers, the Unified CCE solution supports a number of capabilities. However, what Cisco cannot control or enforce is your enterprise policies and procedures for deploying and maintaining a secure Unified CCE solution.
how to design the various security layers required for a Unified CCE network,
this section introduces the differences that are inherent in the applications
making up the Unified CCE solution.
The Unified CCE
solution consists of a number of application servers that are managed
differently. The primary servers, those with the most focus in this document,
are the Routers, Loggers (also known as Central Controllers), Peripheral
Gateways, Administration & Data Servers, and so forth. These application
servers can be installed only on a standard (default) operating system
installation. For Unified CCE components that you install on Windows Server
2008 R2, use only a default retail version of the Windows Server 2008 software.
The maintenance of this operating system in terms of device drivers, security
updates, and so forth, is the responsibility of the customer, as is acquiring
the necessary software from the appropriate vendors. This category of
application servers is the primary focus of this topic.
The secondary group
of servers, those running applications that are part of the solution but that
are deployed differently, are Cisco Unified Communications Manager (Unified
CM), Cisco Unified IP IVR, and so forth. Customers are required to obtain all
relevant patches and updates to this operating system from Cisco. The security
hardening specifications for this operating system can be found in the
Cisco Unified Communications
Solution Reference Network Design (SRND) Guide and
other Unified CM product
The approach to
securing the Unified CCE solution as it pertains to the various layers listed
above differs from one group of servers to another. It is useful to keep this
in mind as you design, deploy, and maintain these servers in your environment.
Cisco is constantly enhancing its Unified Communications products with the
eventual goal of having them all support the same customized operating system,
antivirus applications, and security path management techniques.
Cisco has a security
guide for the primary group of servers. The guide covers details of security
implementation along with general guidance for securing a Unified CCE
deployment. The security guide includes the following topics:
The guidelines are
based in part on hardening guidelines published by Microsoft and other
third-party vendors. The guide also serves as a reference point for most of the
security functionality in the product. The guide also covers installation for
the Automated OS and SQL Security Hardening bundled with the application
installer, Windows Firewall Configuration Utility, the SSL Configuration
Utility, the Network Isolation IPSec Utility, and the Unified CC Security
There are several important factors to consider when deploying firewalls in a Unified CCE network. The application servers making up a Unified CCE solution are not meant to reside in a demilitarized zone (DMZ) and must be segmented from any externally visible networks and internal corporate networks. The VMs must be placed in data centers, and the applicable firewalls or routers must be configured with access control lists (ACL) to control the traffic that is targeted to the VMs, thereby allowing only designated network traffic to pass through.
Deploying the application in an environment in which firewalls are in place requires the network administrator to be knowledgeable about which TCP/UDP IP ports are used, firewall deployment and topology considerations, and impact of Network Address Translation (NAT).
To aid in firewall configuration, these guides list the protocols and ports used for agent desktop-to-server communication, application administration, and reporting. They also provide a listing of the ports used for intra-server communication.
Network Firewall Topology
The deployment shown in the section on AD Administrator created OUs represents the placement of firewalls and other network infrastructure components in a Unified CCE deployment. The design model incorporates a parent Unified ICM
system with legacy peripheral hosts and a child Cisco Unified Contact Center Enterprise with a Unified CM cluster. For this deployment type, do the following:
Block the following ports at the enterprise perimeter firewall:
UDP ports 135, 137, 138, and 445
TCP ports 135, 139, 445, and 593
Deploy Layer-3 and Layer-4 ACLs that are configured as described in the port guides.
Isolate database and web services by installing dedicated historical data servers.
Minimize the number of Administration & Data Servers (ADS) and use Administration Clients (no database required) and internet script editor clients.
Use the same deployment guidelines when the parent Unified ICM or child Unified CCE central controllers are geographically distributed.
Deploy Windows IPSec (ESP) to encrypt intraserver communications.
Use Cisco IOS IPSec for site-to-site VPNs between geographically distributed sites, remote branch sites, or outsourced sites.
Network Address Translation (NAT) is a feature that resides on a network router and permits the use of private IP addressing. A private IP address is an IP address that cannot be routed on the Internet. When NAT is enabled, users on the private IP network can access devices on the public
network through the NAT router.
When an IP packet reaches the NAT-enabled router, the router replaces the private IP address with a public IP address. For applications such as HTTP or Telnet, NAT does not cause problems. However, applications that exchange IP addresses in the payload of an IP packet experience problems
because the IP address that is transmitted in the payload of the IP packet is not replaced. Only the IP address in the IP header is replaced.
To overcome this problem, Cisco IOS-based routers and PIX/ASA firewalls implement
fix-ups for a variety of protocols and applications including SCCP and
CTIQBE (TAPI/JTAPI). The fix-up allows the router to look at the entire packet and
replace the necessary addresses when performing the NAT operation. For this process to
work, the version of Cisco IOS or PIX/ASA must be compatible with the Unified CM
Unified CCE supports connectivity through a NAT except when CTI OS desktop monitoring/recording is in use. The IP address of the agent phone is seen as the NAT IP address, which causes the agent desktop to filter the IP packets improperly. For more information, consult the "IPSec and
NAT Support" section of the Cisco Unified Contact
Center Enterprise Security Best Practices Guide.
While Unified ICM and Unified CCE systems may still be deployed in a dedicated Windows Active Directory domain, it is not a requirement. What makes this possible is the capability of the software security principals to be installed in Organizational Units. This closer integration with AD
and the power of security delegation means that corporate AD directories can be used to house application servers (for domain membership), user and service accounts, and groups.
In a geographically distributed deployment of Unified ICM or Unified CCE, redundant domain controllers must be located at each of the sites, and properly configured Inter-Site Replication Connections must be established with a Global Catalog at each site. The Unified CCE application is designed to communicate with the AD servers that are in their site, but this requires an adequately implemented site topology in accordance with Microsoft guidelines.
The installation of Unified ICM or Unified CCE software requires that the AD Domain in which the VMs are members must be in Native Mode. The installation will add a number of OU objects, containers, users, and groups that are necessary for the operation of the software. Adding these
objects can be done only in an Organizational Unit in AD over which the user running the install program has been delegated control. The OU can be located anywhere in the domain hierarchy, and the AD Administrator determines how deeply nested the Unified ICM/Unified CCE OU hierarchy is
created and populated.
Local Server Accounts and groups are not created on the application servers. All created groups are Domain Local Security Groups, and all user accounts are domain accounts. The Service Logon domain account is added to the Local Administrators' group of the application servers.
Unified ICM and Unified CCE software installation is integrated with a Domain Manager tool that can be used standalone for pre-installing the OU hierarchies and objects required by the software, or can be used when the Setup program is invoked to create the same objects in AD. The AD/OU
creation can be done on the domain in which the running VM is a member or on a trusted domain.
Do not confuse the creation of AD objects with Group Policy Objects (GPO). The Automated Security Hardening, which is provided and follows the standard Microsoft Security Template format, is not added to AD as part of the software installation through the configuration of a GPO. The
security policy provided by this customized template (for Unified ICM/Unified CCE applications) is applied locally when a user chooses to apply hardening, or it can be pushed down through a GPO through manual AD configuration using the provided policy file,
AD Administrator-Created OUs
As mentioned, there
are certain AD objects that may be created by an administrator. The primary
example is represented by an OU container, Unified CCE Servers, which is
manually added to contain the VMs that are members of a given domain. These VMs
must be moved to this OU once they are joined to the domain. This ensures that
some segregation is applied to control who can or cannot administer the servers
(delegation of control) and, most importantly, which AD Domain Security Policy
can or cannot be inherited by these application servers that are in the OU.
As noted before,
Unified ICM/Unified CCE servers ship with a customized security policy. This
policy can be applied at this server OU level through a Group Policy Object
(GPO), but any differing policies must be blocked from being inherited at the
Unified ICM/Unified CCE Servers' OU. Keep in mind that blocking inheritance, a
configuration option at the OU object level, can be overridden when the
Enforced/No Override option is selected at a higher hierarchy level. The
application of group policies must follow a very well thought-out design that
starts with the most common denominator, and those policies must be restrictive
only at the appropriate level in the hierarchy. For a more in-depth explanation
on how to deploy group policies properly, see the
Windows Server 2008 R2
Figure 1. Active
Directory and Firewall Deployment Topology
The following notes
apply to the figure above:
unit object hierarchies are created by the application setup.
Unified ICM Servers and
Unified CCE Servers organizational unit objects must be created by the AD
administrators to separately apply custom Cisco Unified ICM Security Policies
through a GPO if required.
Flexible Single Master
Operation servers must be distributed across Domain Controllers in the
appropriate sites according to Microsoft guidelines.
The Unified CCE
solution relies on Microsoft Windows IPSec and/or Cisco IOS IPSec to secure
critical links between VMs and sites. The solution can be secured either by
deploying peer-to-peer IPSec tunnels between the VMs and sites, or by deploying
a more restrictive and preconfigured Network Isolation IPSec policy, or by
using a combination of both. The peer-to-peer IPSec deployment requires manual
configuration for each communication path that needs to be secured, using the
tools provided by Microsoft. However, the Network Isolation IPSec policy can be
deployed automatically on each VM by using the Network Isolation IPSec utility,
and it secures all communication paths to or from that VM unless an exception
is made. The Network Isolation IPSec utility is installed by default on all
Unified CCE servers.
This guide not only
lists the supported paths, but also information to help users deploy Windows
IPSec, including appropriate settings and much more.
Be aware that enabling IPSec affects scalability in several key
paths in Unified CCE support IPSec. The figure below illustrates the guidelines
provided in this chapter and shows the various server interconnections that
must be secured with either Windows IPSec or Cisco IOS IPSec. The diagram also
shows a number of paths that support TLS.
By providing host
firewall protection on the innermost layer of your network, Windows Firewall
can be an effective part of your defense-in-depth security strategy. Unified
CCE supports the deployment of Windows Firewall on the VMs. The
Cisco Unified Contact
Center Enterprise Security Best Practices Guide contains a chapter on the implementation and configuration of
The configuration of
the exceptions and the opening of the ports required by the application will
still be done locally using the Windows Firewall Configuration Utility, which
is included with the Unified CCE application.
The Windows Firewall
is set up during Unified CCE installation, during which required ports are
The Unified Contact Center Security Wizard allows easy configuration of the security features defined above, namely, SQL Server Hardening, Windows Firewall configuration, and Network Isolation IPSec policy deployment. The Security Wizard encapsulates the functionality of these four utilities
in an easy-to-use wizard-like interface that guides the user with the steps involved in configuring the security feature. (This is particularly helpful when deploying the Network Isolation IPSec policy.) The Security Wizard is installed by default with Unified CCE. The
Cisco Unified Contact
Center Enterprise Security Best Practices Guide contains a chapter explaining the Security Wizard in detail.
A number of third-party antivirus applications are supported for the Unified CCE system. For a list of applications and versions supported on your particular release of the Unified CCE software, see the Compatibility Matrix for Unified CCE DocWiki and the Hardware and System Software Specification for Cisco Unified Customer Voice Portal (Unified CVP), as well as the Cisco Unified CCX and Unified Communications Manager product documentation for the applications
supported. These documents are available on cisco.com.
Deploy only the supported applications for your environment, otherwise a software conflict might arise.
Antivirus applications have numerous configuration options that allow granular control of what and how data must be scanned on a VM.
With any antivirus product, configuration is a balance of scanning versus the performance of the VM. The more you choose to scan, the greater the potential performance overhead. The role of the system administrator is to determine what the optimal configuration requirements for
installing an antivirus application within a particular environment. See the Cisco Unified Contact
Center Enterprise Security Best Practices Guide and your particular antivirus product documentation for more detailed configuration information about a Unified ICM environment.
The following list highlights some general rules:
Upgrade to the latest supported version of the third-party antivirus application. Newer versions improve scanning speed over previous versions, resulting in lower overhead on VMs.
Avoid scanning of any files accessed from remote drives (such as network mappings or UNC connections). Where possible, each of these remote machines must have its own antivirus software installed, thus keeping all scanning local. With a multitiered antivirus strategy, scanning
across the network and adding to the network load is not required generally.
Heuristics scanning has a higher overhead than traditional antivirus scanning. Use this advanced scanning option only at key points of data entry from untrusted networks (such as email and internet gateways).
You can enable real-time or on-access scanning, but only on incoming files (when writing to disk). This setting is the default for most antivirus applications. On-access scanning of file reads yields a higher than necessary impact on system resources in a
high-performance application environment.
On-demand and real-time scanning of all files gives optimum protection. But, this configuration imposes the unnecessary overhead of scanning those files that cannot support malicious code (for example, ASCII text files). Exclude files or directories of files in all scanning modes that are
known to present no risk to the system. Also, follow the guidelines for which specific Unified CCE files to exclude in Unified CCE implementation, as provided in the Cisco Unified Contact
Center Enterprise Security Best Practices Guide.
Schedule regular disk scans only during low usage times and at times when application activity is lowest. To determine when application purge activity is scheduled, see the Cisco Unified Contact
Center Enterprise Security Best Practices Guide listed in the previous item.
Cisco does not test or support intrusion prevention products by vendors such as Sygate, McAfee, and so on. Such products are capable of blocking legitimate application functionality if they incorrectly identify that application as a security threat. These products must be configured to allow legitimate operations to execute.
guidelines regarding when and how to apply updates. All Contact Center
customers must separately assess all security patches released by Microsoft and
install those deemed appropriate for their environments.
Unified CCE servers
(except for the applications installed on VOS) support integration with
Microsoft's Windows Server Update Services, whereby customers control which
patches can be deployed to those VMs and when the patches can be deployed.
updates and determine when they get deployed on production VMs. The Windows
Automatic Update Client (installed by default on all Windows hosts) can be
configured to retrieve updates by polling a VM that is running Microsoft Window
Update Services in place of the default Windows Update Web site.
The Cisco Unified
Communications Operating System configuration and patch process does not
currently allow for an automated patch management process.
The CTI OS (C++/COM toolkit) and CAD agent desktop servers both support TLS encryption to the server. This encryption protects agent login and CTI data from snooping. A mutual authentication mechanism enables the CTI OS Server and client to agree on a cipher suite for
authentication, key exchange, and stream encryption. The cipher suite used is as follows:
Key exchange: DH
Encryption: AES (128)
Message digest algorithm: SHA1
The following figure shows the encryption implementation's use of X.509 certificates on the agent desktops as well as on the servers. The implementation supports the integration with a Public Key Infrastructure (PKI) for the most secure deployment. By default, the application installs and
relies on a self-signed certificate authority (CA) to sign client and server requests. However, Cisco supports integration with a third-party CA. This mechanism is the preferred method because of the increased security provided by a corporate-managed CA or external authority such as Verisign.
The following figure shows the Certificate Authority enrollment procedure to generate certificates used by the agent and the servers. The agent desktop certificate enrollment process is manual. The process requires the creation of certificate signing requests (CSRs) at each endpoint. The CSRs are then
transferred to the certificate authority responsible for signing and generating the certificates.
Cisco Finesse supports HTTPS for the Administration Console and Agent and Supervisor Desktops. HTTPS is not supported for Agent and Supervisor Desktops in large deployments (over 1000 agents).
Unified IP Phone
When designing a
Unified CCE solution based on Unified Communications Manager, customers may
choose to implement device authentication for the Cisco Unified IP Phones.
Unified CCE supports Unified Communications Manager’s Authenticated Device Security Mode, which
ensures the following:
Device Identity — Mutual
authentication using X.509 certificates
Signaling Integrity — SCCP/SIP
messages authenticated using HMAC-SHA-1
— SCCP/SIP message content encrypted using AES-128-CBC
Certain IP phones
support Secure Real-Time Transport Protocol (SRTP). Before enabling SRTP in
your deployment, consider the following points:
The Unified CVP
VXML Browser does not support SRTP. While calls are connected to the VXML
Browser, the calls cannot use SRTP. But, calls can negotiate SRTP once the
media no longer terminates in the VXML Browser.
Unified CCE does
not support SRTP when the deployment uses span-based silent monitoring.
cannot use SRTP.
Outbound Option Dialers do not support SRTP. While calls are connected to the
Dialer, the calls cannot use SRTP. But, calls can negotiate SRTP once the call
is no longer connected to the Dialer.
IP Phone Hardening
The IP phone device configuration in Unified CM provides the ability to disable a number of phone features to harden the phones, such as disabling the phone's PC port or restricting a PC from accessing the voice VLAN. Changing some of these settings can disable the monitoring/recording
feature of the Unified CCE solution. The settings are defined as follows:
PC Voice VLAN Access
Indicates whether the phone will allow a device attached to the PC port to access the Voice VLAN. Disabling Voice VLAN Access will prevent the attached PC from sending and receiving data on the Voice VLAN. It will also prevent the PC from receiving data sent and received by the
phone. Disabling this feature will disable desktop-based monitoring and recording.
Setting: Enabled (default)
Span to PC Port
Indicates whether the phone will forward packets transmitted and received on the Phone Port to the PC Port. To use this feature, PC Voice VLAN access must be enabled. Disabling this feature will disable desktop-based monitoring and recording.
Disable the following setting to prevent man-in-the-middle (MITM) attacks unless the third-party monitoring and/or recording application deployed uses this mechanism for capturing voice streams. The CTI OS Silent Monitoring feature and CAD Silent Monitoring and Recording do not depend on
Indicates whether the phone will learn MAC addresses from Gratuitous ARP responses.