Today, businesses are delivering their mission-critical applications over the wide area network (WAN), also known as the Internet. When network outages occur, the financial losses and disruption of daily work flow can be tremendous. This increased significance of web traffic requires more importance placed on WAN management, which few businesses can afford to overlook. Effective WAN management ensures that critical applications have the Internet bandwidth and reliable connectivity needed to support user and business requirements.

Because online communications has become so central to conducting business, virtually every organization now requires some form of redundant Internet access, the ability to connect to multiple Internet service providers (ISPs) and redirect traffic from congested or broken Internet links to functioning connections. Multi-homing is the ability to connect a single local area network (LAN) or WAN to multiple ISP links. These network links can also be combined into what is effectively one large connection, also known as bandwidth aggregation, or to maintain these links separately and allocate Internet traffic across them by using intelligent link load balancing. Both techniques result in larger pools of bandwidth and greater reliability. Both require application load balancing and automatic link failover.

Border Gateway Protocol (BGP) has long been used for multi-homing by large enterprises and telecommunications companies, but the cost and complexity of BGP makes it impractical for most small and midsized businesses (SMEs). Technologies that use Internet features such as network address translation (NAT) and authoritative domain name system (DNS) have overcome these restrictions, providing more manageable and less expensive outbound and inbound link load balancing and failover solutions. Some of the basic components and associated benefits of WAN-link management are explained in this article.

Application delivery failure over the Internet

WAN link management is accomplished by deploying WAN link controllers that administer multiple Internet connections, and provide automatic failover should one connection have an outage. This capability eliminates the Internet from being a point of failure. WAN link controllers also provide link load balancing to manage the network traffic flow among the network connections. Mission-critical business applications such as VoIP can fail due to their reliance upon a single network connection. If that connection goes down, the VoIP call will fail. Similarly, if network throughput is slow (e.g., a large file transfer slows voice traffic because they are both limited by the same connection), the VoIP call quality will suffer.

Large file transfer consumes the bandwidth, depriving VoIP. Additionally, ISP 1 connection fails.
The WAN link controller prioritizes bandwidth for both VoIP and large file transfers, and directs all traffic to the working DSL connection.

Lower bandwidth costs, and increase overall bandwidth

In addition to dedicated circuits, WAN link controllers can enable organizations to substitute multiple low-cost network connections such as DSL, cable, fiber, wireless, etc., for more expensive T-1s and combine them to deliver the total bandwidth needed to support all the traffic going to and from their offices. Users of these devices can easily and flexibly add bandwidth as their Internet demand increases by adding connections.

As an organization grows, so does the number of employees, partners and customers that use the network. However, the Internet bandwidth requirements might not have grown quite enough to justify the organization to move up to the next level of connectivity, such as replacing a T1 with a T3 or bonded-T1. Instead, WAN link controllers can provide an affordable alternative. Most organizations in urban and suburban areas use broadband or dedicated circuits for their Internet connectivity. T1 connections still cost an average of $400 per month, and can cost upwards of $2,000 per month in more remote areas. This is a cost that many small-to-medium size enterprises can’t afford. However, broadband connections, when bundled together with a WAN link controller can provide the network reliability and high-bandwidth SMEs need at a fraction of the cost.

Many broadband network providers offer business packages with service level agreements (SLAs) at lower prices than a T1 connection. For example, a business-class fiber connection to the Internet might deliver 15/2Mbps up/downstream for $60.00 per month. Cable business Internet packages can range from $60.00 per month for 4Mbps/384Kbps to $160.00 per month for 8/1Mbps.

With two $60.00 business-class cable connections, an organization can save $280.00 per month, compared to a $400.00 T1 connection. Organizations also gain the benefit of redundancy in the event that one of the service providers has an outage.

By applying channel bonding, using a WAN link controller between two sites, network connections from different ISPs without their having to establish peering relationships, an SME, can combine multiple network connections into one virtual “wide-pipe” to gain more overall bandwidth. For example, a business-class fiber connection (15/2Mbps) can be combined with a business-class cable connection (8Mbps/1Mbps) to get a total bandwidth of 23Mbps/3Mbps. Compared to a T1 at $400.00 per month with 1.5Mbps up/downstream, or a channel bonded fiber can be combined with a cable connection with a combined cost of $220.00 per month with 23Mbps/3Mbps  to give a quick return on investment — not to mention the built-in reliability that can’t be found with a single ISP.

Using multiple Internet service providers to protect business assets

As SMEs increase their network traffic between customers, partners and employees, they are implementing disaster recovery solutions. They protect assets by replicating data within specialized storage systems; shielding voice communications with specialized servers and other telephony infrastructure. However, this still leaves the WAN (Internet) as a point of failure. Without network connectivity failover for reliable Internet traffic, disaster recovery efforts are incomplete. The Internet has always presented challenges to business as it is not under the domain and protection of internal IT personnel. WAN link controllers enable IT personnel to gain control of Internet infrastructure by enabling them to affordability add and remove network links to best fit their business requirements, while achieving built-in Internet redundancy.

Implementing disaster recovery for network connectivity using multiple Internet connections is cost-effective insurance. Unfortunately, many SMEs don’t address network uptime until their service provider has an outage, and they lose productivity, data and even revenue. Network uptime as a form of risk management is not a high-priority until their network goes down, and their business is adversely affected.

Deploying multiple Internet service providers for purposes of disaster recovery allows a company to continue doing business without interruption, even during a service provider outage. There are many deployment options available using multiple ISPs. An example would be allocating different network connections to different applications. Using this technique, voice traffic and large file transfers can be dedicated to separate network links. In this way, large file transfers will not slow down voice traffic. If one of the ISPs has a network outage, both the voice and file transfers will be automatically directed over to the working ISP connection. Once the other ISP comes back online, the traffic will be automatically directed back to the original traffic flow configuration.

There are other benefits that result from WAN link management, which include quality of service assurance and site redundancy.

Quality of Service (QoS)
QoS and traffic shaping are the ability to prioritize network traffic to ensure that adequate bandwidth is always available to specific applications, especially during periods of congestion. QoS rules determine bandwidth minimums and maximums for specific types of traffic use link load balancing and automatic failover to direct this traffic to links with sufficient bandwidth. 

Site Redundancy
Many businesses need to redirect Internet traffic to a disaster recovery site should a catastrophe disrupt a main site. In recent years, the cost associated with the technology needed to ensure that site failover and failback occur reliably and predictably has declined significantly, making this capability practical and affordable even for the smallest businesses.

Service provider benefits

With a WAN link management solution, managed service providers can provide business-class service reliability for outsourced applications over lower-cost broadband links. By removing the deterrents associated with reliability, security and cost, ISPs that service SMEs can now provide affordable, reliable and secure Internet connectivity utilizing a variety of link options that best meets the needs of their customers. Service providers are now able to take advantage of their economies of scale and managed service expertise, and provide additional services that, until now, had been exclusive to large enterprises and internal corporate networks.

Summary
Automatic and intelligent WAN management can be achieved by several methods that vary considerably in expense and complexity. At the less-complex end of the spectrum are WAN link controller appliances that eliminate the deployment barriers and cost of multi-homing with BGP. More complex and expensive approaches involve the use of heavy-duty routers and highly specialized network technology. Regardless of the technology used, the requirements of most SME’s for WAN management will include the features described above.

Marc Goodman is the director of marketing at Ecessa.