When selecting Enterprise Edge technologies, consider the following factors:

■ Support for network growth: Enterprises that anticipate significant growth should choose a technology that allows the network to grow with their business. WAN technologies with high support for network growth make it possible to add new branches or remote offices with minimal configuration at existing sites, thus minimizing the costs and IT staff requirements for such changes. WAN technologies with lower support for network growth require significantly more time, effort, and cost to expand the network.

■ Appropriate availability: Businesses heavily affected by even the smallest disruption in network communications should consider high availability an important characteristic when choosing a connectivity technology. Highly available technologies provide inherent redundancy where no single point of failure exists in the network. Lower-availability technologies can still dynamically recover from a network disruption in a short time period, but this minor disruption might be too costly for some businesses. Technologies that do not inherently provide high availability can be made more available through redundancy in design, by using products with redundant characteristics such as multiple WAN connections, and by using backup power supplies.

■ Operational expenses: Some WAN technologies result in higher costs than others. A privateline technology such as Frame Relay or ATM, for example, typically results in higher carrier fees than a technology such as an IPsec-based IP VPN, which takes advantage of the public Internet to help reduce costs. It is important to note, however, that migrating to a particular technology for the sole purpose of reducing carrier fees, without considering network performance and QoS, can limit support for some advanced technologies such as voice and video.

■ Operational complexity: Cisco MAN and WAN technologies have varying levels of inherent technical complexity, so the level of technical expertise required within the enterprise also varies. In most cases, businesses can upgrade their MAN or WAN and take advantage of the expertise of the existing IT staff, requiring minimal training. When an enterprise wants to maintain greater control over its network by taking on responsibilities usually borne by an SP, extensive IT training could be required to successfully deploy and manage a particular WAN technology.

■ Voice and video support: Most Cisco MAN and WAN technologies support QoS, which helps enable advanced applications such as voice and video over the network. In cases where a WAN technology uses an SP with a Cisco QoS-certified multiservice IP VPN, an adequate level of QoS is assured to support voice and video traffic. In cases where the public Internet is used as the WAN connection, however, QoS cannot always be guaranteed, and a highbandwidth broadband connection might be required for small offices, teleworkers, and remote contact center agents using voice and video communications.