MPLS and Ways to Avoid Additional Packet Loss After a Burst Loss

By Mae Kowalke, TMCnet Contributor

After a burst of packet loss, the damage often is not done. Commonly, there is additional packet lost after a burst of loss because the network trouble is more than just a momentary issue.

“Not only is packet loss not uniformly distributed—as simple WAN emulators model it—and most quoted performance numbers do as well--but it is completely unpredictable how long episodes of packet loss will endure,” wrote Andy Gottlieb in a recent article, a networking veteran.

“A small portion of the time packet loss remains high for an extremely long time,” he added. “But since there is no way of knowing how long a ‘loss episode’ will go on, if one wants predictable application performance, it's simply not safe to use a network path which is exhibiting a run of packet loss (versus simply an isolated packet or two lost every so often) until said network path has demonstrated that packet loss has gone away.”

There are several ways to deal with the issue, including multi protocol label switching (MPLS) and WAN virtualization.

MPLS, pioneered by UNSi, labels the different packets in a network, thus enabling faster transfers and processes, and it commonly is used to divert and lead traffic through congestion, bottlenecks, and even link failures.

There are three types of MPLS: point-to-point or the pseudowire VPN that makes use of virtual leased lines to be able to provide a point-to-point connection between two specific sites; Layer 2 VPN, which is a virtual private LAN service that provides a switch in the cloud type of service; and Layer 3 VPN, a virtual private routed network that makes use of layer 3 virtual routing and forwarding to make routing between individual clients and the service provider possible.

It is this third type, Layer 3 VPN, that most supportive for businesses and corporate companies as it directs and diverts traffic between the corporations and data center locations, according to a recent TMCnet article.

WAN virtualization also is a good method for dealing with burst packet loss and the potential for additional ensuing loss.

“A WAN Virtualization implementation that continually measures packet loss in real-time and can react quickly enough can switch away from a network path exhibiting a run of loss,” noted Gottlieb in his recent post on the topic. “As importantly, it can start to use that path again for user traffic only after the path has demonstrated (using heartbeat packets) that it is no longer experiencing packet loss.”

Although MPLS WANS helps reduce the problem, Gottlieb is bullish on WAN virtualization.

“While traditional WAN Optimization solutions do their best to minimize and mitigate the effects of loss, they can't address the core problem: the loss itself. With WAN Virtualization, you can do more than get a weather map and a real-time weather status - for the first time you can actually do something about the weather,” he enthused in his post.

“This is why WAN Virtualization enables the use of otherwise relatively high loss (and so less predictable) inexpensive Internet links, he added. “Mitigating the effects of loss combined with avoiding those cases of long periods of loss is the key to this.”

To find out more about UNSi visit the company at ITEXPO Miami 2013. Taking place Jan. 29- Feb 1, in Miami, Florida, be sure to visit UNSi in booth #923 and #925. For more information on ITEXPO (News - Alert) Miami 2013, click here.