What is SD-WAN?
The Benefits of SD-WAN
- Automatic Failover
- Centralized Management
- Bandwidth Management
- Cost savings
- Ease in deploying
What is SD-WAN?
SD-WAN stands for Software-Defined Wide Area Network. First, let’s familiarize you with the term WAN or Wide-Area-Network. It is easily understood by thinking of it as connecting to offices or services outside your building. Consequently, connecting services inside your building is thought of as the LAN or Local Area Network. There are multiple ways of connecting two or more offices together across a WAN. The different WAN technologies fall into at least two categories. Site-to-site networking and site-to-multisite networking.
Site to Site Networking
One form of site to site technology uses “private line” or direct circuits from one site to another site. Think of it as a direct highway from one office to another office. One major downside to private line circuits is that if they have an outage there was no “secondary” path available unless a separate back-up circuit was purchased. They are also costly because they require dedicated hardware and cabling along their path.
Site to Multi-site networking
Site to Multi-site technologies allowed one site to connect to multiple sites without having to install a direct circuit to each site. Popular multi-site technologies are Frame Relay (1990’s) and MPLS (2000’s). The benefits of the multi-site connection methods were many. One particular big benefit was utilizing your carrier’s network to provide “multiple paths” to get between the two sites. Network downtime was reduced because you no longer had just one circuit between the locations. Instead, both sites had an access circuit to the provider. The provider’s network was then used to connect your office’s access circuits. A single circuit outage along the path would automatically re-route your traffic and keep your connection active.
A good comparison is having multiple highway paths between two offices. A problem on one highway could easily be avoided by using another highway.
One of the disadvantages of a MPLS network is that you are married to your MPLS provider. MPLS is specific to your network provider and as you connect multiple sites you are dependant on your provider to deliver the MPLS to your site. Consequently, if your network provider had difficulty getting to your site then the MPLS connectivity would suffer. Sometimes the carriers are not competitive in all states. The potential existed that some of your sites could be more costly than others. For that reason, it was often necessary to price your network sites on several providers to determine the most cost-effective provider.
SD-WAN is s Multi-site WAN technology because it allows one site to connect to all other sites very easily without requiring a special circuit to that site. In addition, a huge benefit of SD-WAN is that it is carrier and technology are independent. SD-WAN allows any carriers circuits to connect to your equipment. Additionally, any connection type (fiber, coax, ethernet, DSL, ADSL, SDSL, and wireless 3G/4G) can be used. This is especially helpful for a number of reasons. First, you are no longer tied to a particular provider at all your sites for network connectivity. Second, the ability to use less costly cable/coax or DSL circuits over more costly ethernet circuits is very convenient. Third, the SD-WAN appliance allows you to aggregate the bandwidth of multiple circuits. Instead of a “primary” and “back-up” network you have what is considered a “live – live” network. There are many more advantages that we will discuss but those three are big improvements over the WAN technologies we discussed above.
Benefits of SD-WAN
The benefits of SD-WAN, lie in the hardware and software that you choose for your network that provides the following functionality.
A) Centralized Management across the network
A single pane of glass with web based access to the network with management changes across the network with just a few key clicks can be completed in minutes, not days or weeks. This improves network changes and speeds deployments across all sites. Standard templates can be saved to standardize features and settings across all sites.
B) Better traffic Routing
SD-WAN implementations allow for multiple network connections to be made in the hardware and managed by the software. In addition, business applications can be tailored to be sent over various links depending on prioritization or the links ability to handle packet loss, jitter, and latency. These policy-based routing rules can dynamically manage your applications with priority given to the most critical applications.
C) Full network visibility
The ability to measure the network performance across the network, look for problems and address them in realtime. In addition, the ability to optimize traffic across applications.
D) Integrated Security
The SD-WAN appliances provide not only basic firewall capability like stateful inspection and policy-based filtering but also Next-Generation Firewall (NGFW) services including intrusion prevention, URL filtering and more eliminating the need for multiple specific hardware devices.
E) Ease in provisioning
Zero-touch provisioning allows the network administrators to pre-configured profiles, including device configuration, network policies, software updates and additional options such as rebooting the device once provisioning is complete. The profiles can be implemented automatically through the network. This ease in provisioning enables hardware to be sent to the sites and be operational very quickly without the need for highly technical personal. The rapid deployment also allows for scalability across the network.
F) Traffic Prioritization
SD-WAN allows critical applications like voice and video, that are sensitive to latency, to be prioritized over non-critical applications such as e-mail and web browsing. In addition, the SD-WAN appliance can look for the best circuit availability based on characteristics like packet loss, jitter, and latency and send the traffic to the best links in real-time.
G) Automatic Failover
SD-WAN has the ability to dynamically send traffic either at the packet level or session level over different circuits in the event of a circuit outage. In real-time, the packets can automatically fail-over from one circuit to another preventing dropped calls or session termination. This allows for improved business continuity for the applications and disaster recovery.
H) Bandwidth Management
SD-WAN allows you to aggregate multiple circuits together for better service. For instance, a high-quality 10MB dedicated internet circuit combined with a lower quality but high bandwidth 75Mb x 15MB coax circuit is a great way to improve overall service to a site. Configuring the circuits in a “live-live” scenario allows both circuits to work in tandem with one another. Critical traffic like voice and video can be sent over one circuit while non-critical traffic can be sent over the other. You can also combine two lower-cost circuits to reduce costs over the more expensive circuits.
SD-WAN allows companies to reduce their network costs while improving application performance, network security, visibility, and control while allowing for rapid deployment.
