(Accedian Networks') EtherNEWS Blog

Understanding why and how one-way traffic performance measurement in wireless backhaul networks can bring essential visibility of performance and help optimize the use of scarce network resources

Accedian Network’s latest technology white paper reveals that not only do round trip measurements provide incomplete or inaccurate results, they can also provide misleading information that can result in costly over-provisioning, as well as lack of problem identification and real understanding of network performance.

The paper demonstrates how the proper deployment of devices that carry wire rate operational data while correctly measuring application and service traffic performance can bring the correct insight on how a network is functioning. Devices that properly measure uni-directional data flow, aggregate OAM information while passing data at wire rate will be a critical element in understanding and cost-effectively engineering the networks of the future.

As backhaul networks migrate to Ethernet 4G/LTE and move from single to multiple class of services, these devices will be essential to provide visibility of performance issues that can remain a mystery when only round trip, non-deterministic measurements are used.

The paper examines traffic patterns in mobile backhaul networks and how they impact provisioning and quality of service. It investigates the risks and costs of relying on round trip measurements and then looks at measurement standards and how that knowledge can be used to both engineer and operate the wireless backhaul as it migrates to new standards and usage patterns.

Mobile Bursty and Bandwidth Thirsty

Not only are traffic patterns distinct directionally but they’re also very “bursty” in mobile environments where everyone gets on their phone at the end of an event, etc. This means that burst of traffic can occur at any moment impacting the quality of services. High priority traffic interspersed with long packets of data can occur at any time in the network. The question to be answered is “how will the applications function when the network is under stress?” and what are the signs, so that action can be taken.

Okay if that’s the problem how do we measure the network? Let’s start by looking at traditional methods in operational networks.

Round Trip Measurements: Drawing Incorrect Conclusions

Round trip delay measurements can provide misleading results in networks with asymmetric traffic patterns – and that’s pretty much all of them.

In most examples of backhaul networks, the southbound data being downloaded from web sites, streamed audio content and cloud-based applications dominate the traffic patterns, increasing the likelihood of consuming more bandwidth with longer delays in that direction, especially as the physical limitations of the connection are approached. In this case returning round trip data may return rapidly giving misleading results on the southbound times.

Another instance is where the north and southbound data paths are not the same. As can be seen in the above diagram, this can lead to further problems in both measurement and fault isolation, rendering round trip measurements of no value since they are often oblivious to route diversity.

The lack of information leads to the inevitable conclusion that in order to maintain customer satisfaction the network is over-provisioned at very high cost.

To download the complete white paper, please click here.

Speed of deployment is critical in the fast-evolving 4G cellular world as operators rush to bring on advanced mobile services that benefit from the greater speed and capacity enabled by LTE. In 2009, one of the top four Tier 1 cellular mobile operators—and clear leader in customer support and service in the U.S.—saw a unique opportunity to build revenue and gain customers by being first to market with 4G/LTE-based services.

A premature, unsuccessful and widely publicized attempt by a competitor who tried rolling out 4G services on a legacy backhaul network presented a window of opportunity for the operator to be first out of the gate with its own backhaul network to support emerging high bandwidth 4G/LTE based services.

The operator had to therefore drastically accelerate its plans, and build out its 4G backhaul in just one year rather than the two or three years it had originally planned. This posed several challenges. First, the operator’s infrastructure did not reach most of the sites, and trenching for fiber would have cost too much and taken too long. To solve this immediate challenge, the operator opted to buy backhaul capacity from Alternative Access Vendors (AAVs) whose networks passed in proximity to the cell sites. But dealing with over 50 AAVs, each with their own service characteristics brought logistical headaches and considerable complexity. It also created dependence on third parties for a critical part of the service. Now, factors beyond its control could cause deterioration in service at any time, so ongoing performance monitoring became a critical requirement.

Next, the operator would need to turn-up nearly 100 cell sites per day, a seemingly impossible endeavour given that most were not reachable by the operator’s existing circuits. This electronic “rush” of unprecedented speed would also create a further challenge in ensuring that the rapidly growing backhaul infrastructure continued to meet the operator’s stringent SLAs.

Finally, the operator wanted to use Carrier Ethernet technology for the backhaul to take advantage of its greater capacity, economies of scale, and ultimately lower costs. Ethernet, however, is non-deterministic, which means that packet transmission can vary depending on traffic conditions. Careful configuration is required to ensure that KPIs such as latency and delay variation are kept within specified bounds. This is especially important for the LTE technology used in 4G services, since the increased performance renders the network even more sensitive to these KPIs.

Read the complete case study on how the operator was able to move quickly and pre-empt the competition by turning up 4G at 30,000 cell sites in one year, while providing the service assurance necessary to ensure consistent and reliable service delivery from over 50 AAV Carrier Ethernet backhaul networks to the operator. Read Case Study

Mr. Milbury brings over 30 years of experience exercising financial, operational and governance responsibilities in the technology sector. “Paul’s vast experience in building successful companies and creating shareholder value will be pivotal to Accedian as the Company prepares for the next phase in its growth,” said George Riedel, Chairman of the Accedian Networks Board of Directors. “He brings an invaluable perspective to the Board with direct involvement in public company control and governance, merger and acquisition strategy/execution, IPO preparation and execution, investor relations and treasury.”

“Accedian is clearly one of the leaders of the 4G/LTE revolution, and a key contributor in making Carrier Ethernet technology suitable for mobile backhaul services,” said Paul Milbury. “Accedian’s high performance service assurance solution ensures the success of service providers around the world who are racing to deliver 4G services over Carrier Ethernet networks. I’m very excited to be in a position to contribute to the Accedian Board as the company makes this journey.” Read Press Release

It is hard to say which of two developments in mid-August 2011–Steve Jobs stepping down as Apple CEO, or Google’s purchase of Motorola Mobility–will have the more significant impact on the device and application markets, which in turn will drive the bulk of service provider revenue, in the future.

Either development holds the potential to reshape important parts of the application, content, mobile and broadband business segments. Looking first at the Google acquisition, there is potential for a significant undermining of the “open” approach Android was intended to employ, and less support for the Android ecosystem.

Google says it intends to run the Motorola handset business at arms length, which is a wise statement for a provider of operating system software to multiple handset manufacturers. However, Google will now have a “channel conflict” with its licensees. The long-term issue is how Google will balance being both a supplier of a major open source mobile operating system with its new role as a handset manufacturer. Indeed, the entire Android ecosystem has to wonder whether the market will change now that Google has gotten into the handset business.

The beginning of the passing of the Steve Jobs era might have equally broad implications. Though virtually nobody expects any changes in the near term, there arguably are greater questions about Apple’s role in mobile, tablet, content and application markets long term. Steve Jobs was almost singularly unusual among the ranks of U.S. and global executives for his stubborn unwillingness to do business the way virtually everybody else does. While, most firms try to take share in markets, Steve Jobs tried to create markets.

Most firms survey customers and prospects and conduct market research to figure out what to build or create next. Apple never did that. Instead, Jobs tried to figure out what unknown needs consumers had, and then built products that met those unknown needs. How many CEOs would be willing to repeatedly bet their companies on “hunches” about what new products people might really want, even when they were unable to articulate those needs? The answer is that virtually nobody operates that way.

Long term, the issue is whether Apple can indefinitely continue to create new markets, and dominating products, over time. In the near term, the product pipeline is set and the management team is intact. But that cannot last forever. And since Steve Jobs was unusual, one would have to expect a reversion to the mean, at some point. In other words, though it is not yet the case that “Apple’s best days are behind it,” one has to believe that, at some point in the future, this will be the case. Whether that is three years, five years or more is hard to say. But that obviously means mobile device, content, application, mobile service provider and other markets will move in different directions, over the longer term. Though many will bristle at the notion, there might be less widespread impact from innovation, overall.

Apple, under Steve Jobs, reshaped the computing user interface, the mobile phone, the PC, the music and portable music player business, the application business, and is starting to work on the broader content business (print, TV, video and film). Few others have driven those sorts of broad transformations.

In the future, Apple might not reshape some markets it could have. Television and payments come to mind. Apple will be a less-robust competitor, over the longer term. Competitors will be happy about that. But one has to wonder what big new markets will not be created or reshaped only because Steve Jobs will not be around forever, to think about how to do it better.

If I had to guess today, I’d say the Google purchase of Motorola will have greater impact in the next three years. But I’d also have to say the passing of the Steve jobs era will have wider impact over the long term. That’s the measure of the man.

OCTOBER 2 – 5, 2011 Orlando, Florida New Backhaul Opportunities for AAVs October 4, 2011 – 9:20 a.m. The LECs have dominated the backhaul market in the 2G and early 3G era, but AAVs and MSOs are playing a much larger role in building out backhaul capacity for the mass-market 3G and 4G era. Join us in this session that looks at the business models and technology solutions that alternative wholesalers are pursuing and how they are positioning their capabilities to meet the increasingly demanding SLAs of the wireless carriers.

October 24-27, 2011 Chicago, Illinois Building Better Backhaul for Next-Gen Services October 24, 2011 – 3:05 p.m. Mobile operators need more than just big pipes for backhaul. Whether the mobile network operator (MNO) is building its own backhaul network or contracting for wholesale backhaul services, it must maintain the appropriate quality of service to ensure reliable voice calls and handoff between cells as bandwidth demand swells with emerging video and multimedia applications. In this session, we will discuss how MNOs are enabling faster, more reliable connections through performance validation and circuit management.