Information system budgets can run into millions of dollars. As large organizations increasingly rely on electronic data for managing business activities, the associated costs of computing resources continue to rise. With this in mind, your basic network plan should include the following:

• Environmental consideration—Include the location of hosts, servers, terminals, and other end nodes; the projected traffic for the environment; and the projected costs for delivering different service levels.

• Performance constraints—Consider network reliability, traffic throughput, and host and client computer speeds. For example, network interface cards and hard drive access speeds

• Internetworking variables—Include the network topology, line capacities, packet flow assignments, redundancy and fault tolerance factors, backward compatibility (co-existence and interoperability), and security.

Redundancy is critical considering the number of vital business applications running on the network. If you have a distributed network with several access layers to remote offices, and you have a failure from the distribution layer to the core without redundancy, you have loss of network service for a large number of people. If you have redundancy in the distribution layer and the core, you can potentially lose one or more circuits without disturbing service to any particular group of users. Depending on the application, you may also need some redundancy from the access layer to the distribution layer.

Because of redundancy, if you drop a link at any one point in the network, every remote group or user still has a path to get back to the core. Even if you cut off the connection from one of the distribution switches back to the core, you still have access to the core for every user.

For more information on redundancy planning, see the Redundancy and Load Sharing Design Guide.

Capacity and QoS are major considerations in a converged network and effect one another. QoS is needed to prevent applications from using more than a fair share of bandwidth and degrading the performance of other applications. At the WAN interface, QoS is needed to allocate expensive wide area capacity among applications.

Bandwidth and QoS requirements are easy to figure in a multilayered design because the traffic flow is fairly predictable. You can also have end-to-end QoS in a multilayered design. End-to-end QoS is critical when you have real-time applications, such as a voice conversation or video presentation, and you have non-real time applications that can interfere with the real-time applications. For example, if the real-time and non-real time applications arrive at the same layer at the same time, the network must pass the real-time packets first, as well as keep latency and jitter low. QoS end-to-end is the answer.

Consider Call Admission Control (CAC) as an alternative to QoS. CAC limits the amount of traffic allowed onto the network at the ingress point. Because you know that the network will be congested at various times during the day, you can disallow additional traffic by using CAC. Also consider using traffic-shaping techniques using a traffic-shaping devices. A combination of QoS, CAC and traffic shaping will provide optimal performance for applications on a converged network.

Managing link speed mismatches is the last element of traffic management. The mismatches, called chokepoints or bottlenecks, are a basic design issue whenever a large capacity link generates traffic destined for a low capacity link.To avoid the mismatches, carefully analyze the traffic and the device capabilities, then upgrade the interface (if needed) and apply a combination of CAC and QoS.

For more information on QoS, see the Enterprise QoS Solution Reference Network Design Guide.

Cisco recommends multiple layers of security technologies to prevent a single configuration error from jeopardizing the security of the network. Cisco also recommends operational processes that ensure prompt application of software patches, timely installation of new security technologies, and performance of regular security audits and assessments.

As you begin to design your network, rank the importance of your network assets and services by considering these factors:

• What keeps you in business?

• How do you make money?

• Does loss of data or privacy equal lost money?

• What about regulatory compliance?

• How do you protect your critical data?

• Where does voice fit?

Then consider the potential threats to your business, which may include

• Toll fraud

• Eavesdropping

• Address spoofing

• Fake caller identity

• Media tampering

• Denial of service

• SPAM, SPIT (SPAM over IP telephony), and SPIM (SPAM over Instant Messaging)

In addition to the operational processes, advanced security technologies should be reviewed and considered. Security technologies can be categorized as follows:

• Network security

  • Virtual LANs (VLANs)

  • Access control lists (ACLs)

  • Stateful firewalls with protocol aware inspection

  • Virtual Private Networks (VPNs)

  • QoS

  • Dynamic Address Resolution Protocol (ARP) inspection

  • Dynamic Host Configuration Protocol (DHCP) snooping

  • Port security

  • Network intrusion prevention

• Host security

  • Cisco Security Agent

  • Third-party anti-virus software

  • Host-based firewalls

  • Hardened operating systems

• User authentication, authorization, and accounting security

  • Phone image authentication

  • Multilevel administration privileges

  • Call detail reporting

For more information about Cisco end-to-end security designs, see the Cisco SAFE guidelines at http:/​/​www.cisco.com/​c/​en/​us/​solutions/​enterprise/​design-zone-security/​landing_​safe.html. For more details about Cisco integrated network security solutions, see the following resources:

• Security Products and Solutions

• Secure Unified Communications

• Cisco Support Community for Security

System testing defines and validates the interoperability and stability of components that comprise a complete and optimized Cisco Collaboration system. The system test includes installing, configuring, and testing contact center hardware and software that are designed to work together in a predictable, effective, and reliable manner.

Call flow analysis is an important part of determining your business requirements. Call flows show you how your calls are handled physically, which drives your equipment requirements. Call flows also help to determine the network routing plan.

Cisco Preferred Architecture and Cisco Validated Designs

Cisco Preferred Architectures and Cisco Validated Designs (CVDs) help you design and deploy powerful, comprehensive, and scalable collaboration architectures with collaboration services, such as Cisco Unified Communications, Video Collaboration, and Contact Center. Cisco Preferred Architectures and CVDs guides provide the framework for systems design based on common use cases or current engineering system priorities. Cisco engineers have tested and documented each CVD to help ensure a faster, more reliable, and more predictable deployment.

• Cisco Preferred Architecture design overviews provide a prescriptive, end-to-end architecture, an understanding of the individual products and their role in the overall architecture, along with basic design best practices and a sample Bill of Materials

• CVDs provide detailed design and step-by-step deployment information for collaboration deployments and are based on Preferred Architectures.

For samples of Cisco Preferred Architecture and CVDs see Cisco Validated Designs for Collaboration.

Tested Deployment Models

Cisco has developed a variety of site models as standard architectures. These models were tested and optimized for maximum efficiency and performance. You can derive your network design by choosing the deployment model that most closely matches your business and then adding the specific features and applications that meet your business needs.

For information about Contact Center deployment Unified Contact Center Enterprise models tested by the Collaboration Systems Validation team for this release, go to https:/​/​www.cisco.com/​c/​en/​us/​td/​docs/​voice_ip_comm/​uc_system/​V10-6-1/​VTGS_​BK_​T6C916AE_​00_​test-bed-unified-cce.html.

For information about Contact Center deployment Unified Contact Center Express models tested by the Collaboration Systems Validation team for this release, go to https:/​/​www.cisco.com/​c/​en/​us/​td/​docs/​voice_ip_comm/​uc_system/​V10-6-1/​VTGS_​BK_​T13FBE9C_​00_​test-bed-unified-ccx.html.

For information about Collaboration tested deployments and site models for this release, go to https:/​/​www.cisco.com/​c/​en/​us/​td/​docs/​voice_ip_comm/​uc_system/​V10-6-1/​VTGS_​BK_​TCEB367A_​00_​tested-deployment-and-site-models.html.

Cisco Collaboration Systems Solution Reference Network Designs (SRND)

For additional guidelines, recommendations, and best practices for implementing Collaborations networking solutions, go to Cisco Collaboration Systems 10.x Solution Reference Network Designs (SRND).

Preparing for Your System Upgrade

Note	There may be more than one upgrade path based on the software deployed in your specific environment. For more information, see Upgrade Paths.

This topic discusses information to be aware of before the actual upgrade process such as the different contact center components, upgrade release versions of components involved in the upgrade, and upgrade dependencies and considerations.

For more information, see:

• Cisco Collaboration Systems Compatibility Matrix

• Critical Caveats

When your upgrade plan is in place and you are ready to upgrade, go to Performing Your System Installation.