Best ways for Establishing a Robust WAN Architecture

By CIOReview | Thursday, July 21, 2016

The burgeoning demand of Virtual Private Network (VPN) and the cloud computing technology has altered the phase of networking over the past few years. As most applications across the globe are being distributed using network services, companies are constantly striving to adopt a high-end Enterprise WAN Network, which happens to lead the market in terms of efficiency.

The need for an effective enterprise WAN architecture arises not only due to the limitations of the existing technologies, but also because of the several new technologies with enormous possibilities in the Enterprise WAN realm.

Traditional WAN Designs

WAN designs are based on certain application requirements, geography, and the available options offered by service providers. Selection of an appropriate physical WAN technology happens to be the initial step towards adopting a robust WAN connection. Options include:

• Circuit-switched network: Circuit-switched network establishes a physical path directed towards a single connection between two endpoints in the network. This operation takes place for the entire duration of the connection. The ordinary voice telephone service over public switched telephone network (PSTN) is circuit switched. It simply means that telephone companies reserve a specific physical path to the number being called. For the whole duration of the call, no one else can use the engaged physical lines.
• Leased lines: This is a point-to-point connection which is reserved for transmissions rather than being used only when a transmission is needed. Synchronous transmission is implemented on a usual basis.
• Packet and cell-switched network: Known as carrier-created permanent virtual circuits (PVC) or switched virtual circuits (SVC), this type of network distributes and delivers packets among different sites. Users can share a common carrier resource and also have the power to use different paths through the WAN. This facility enables the carrier to utilize its network infrastructure more efficiently than the leased point-to-point lines. Examples of the packet-switched networks are Switched Multimegabit Data Service (SMDS), Frame Relay and X.25.

Significance of a Top-notch WAN Backup Strategy

Enterprise WAN solutions require WAN backups to assure high availability between sites. Branch offices should experience minimum downtime during the event of a primary link failure. To tackle the event, backup connections are established using either permanent or a dial-up connection.

Primarily used WAN backup options are as follows:

• Permanent secondary WAN link: Implementing an additional permanent WAN link between each central office (CO) and remote office effectively makes the network efficient and stable enough to handle faults.
• Dial backup routing: This backup solution uses dialup services such as ISDN. The process involves a router initiating the dial backup line based on the object tracking parameters or in case of a failure detected on the primary circuit. The backup line delivers WAN connectivity until the primary circuit is restored and then terminates it.
• Enhanced bandwidth: Assigning additional bandwidth decreases the response times when the connected router supports load balancing between two parallel links. Automatically, the process of load balancing is carried out through the routing protocol.

Picking a Suitable Enterprise WAN Architecture

After identifying the essential requirements for remote connectivity and understanding the WAN designs, the next crucial step involves the selection of a reliable and fail-proof WAN architecture.

Enterprises must consider the following factors:

• Appropriate availability: Considering the availability of appropriate connection technology should always be of the utmost priority for enterprises experiencing heavy impact even by the slightest disruption in the network. Highly available technologies offer inherent redundancy with zero chances of failure in the network. Whereas, least available technologies has the capacity to recover from a minor network disruption, but it might turn out to be too costly for some enterprises.
• Operational expenditure: The overall costs of WAN technologies are based on performance and the available support for its features. Migrating to a technology with the sole intention of reducing the carrier fees and ignoring the network performance and QoS can limit the level of support from the vendors.
Operational complexity: Most WAN technologies have higher levels of technical complexity. Accordingly, the level of technical expertise also needs to be elevated within the organization. When a company chooses to maintain a greater control over its network, extensive IT training facility would be required to successfully incorporate and manage a complex WAN technology.
• Network segmentation support: Logically segmented networks are easily manageable for enterprises focusing on reducing the level of complexity. When compared to separate physical networks, it results in a considerable decrease in the expenses associated with equipments, network administration, maintenance and network carrier charges. Another advantage is enhanced security as network segmentation can isolate departments or limit unauthorized access to the enterprise network.

Constructive Capacity Planning

A highly productive function of network capacity planning will determine the exact amount of bandwidth needed for the network. It is crucial to determine what capacity of network will accommodate a growth over a specific period of time. For instance, Are you adopting a VDI or video streaming? Are you integrating new applications into the workflow? or Are you preparing for mergers and acquisitions? To ensure high success rates, insights into the current bandwidth usage as well as historical capacity usage is highly essential. An accurate provisioning and budgeting also stages an efficient network capacity planning.

Well Defined QoS Implementation

QoS polices ensures whether the congestion points are resolved and additional bandwidth is allocated to the critical network traffic. In the absence of appropriate QoS policies, allotting sufficient bandwidth to business-critical applications become burdensome. Lacking a deep understanding of the type of traffic passing through a network restrains the ability to predict if the QoS parameters are meeting the desired target levels. A systematic network traffic monitoring will effectively offer the visibility needed to plan network capacity and furnish the QoS.

What Exactly Does the Future of Enterprise WAN Looks Like?

Visualizing the future scenario, we are able see a remarkable transition from static networks depending on expensive, in-house physical infrastructure towards a well-organized and distributed system. Boosting the level of productivity, it will help to combine the power of Internet broadband and cloud infrastructure.