CTIA: Allot sniffing packets all the way to the cell

By their very nature, cellular systems are composed of thousands of individual networks, each cell acting in concert to its neighbors when a subscriber or enters or leaves its radius, but otherwise acting independently. Thus the problems that would normally affect the network as a whole can afflict individual cells on a case by case basis. One cell could be suffering from massive congestion or subscriber overload, while its neighbors might be experiencing little or no activity.

When deep packet inspection (DPI) techniques were first transplanted from the wireline network to wireless, vendors weren’t able to take the distributed nature of the wireless network into account. DPI could sniff out traffic patterns in the network as a whole, but couldn’t peer into the cell where a good deal of the congestion problems occurred said, Jonathan Gordon, director of marketing for Allot Communications (NASDAQ:ALLT).

“You can pinpoint congestion in a fixed network—it doesn’t move around a lot,” Gordon said. “In a mobile network congestion not only moves around from place to place but congestion issues are more acute.” A few subscribers using bandwidth heavy apps can bring a cell to its knees, Gordon said, and as they move from cell to cell they transplant congestion from one part of the network to another almost instantaneously--problems one doesn’t find with cable or DSL networks. Traditional wireline DPI solutions, including Allot’s, couldn’t account for the dynamics and extremes of congestion on the wireless network.

But Allot is now rectifying that imbalance, announcing today upgrades to its Service Gateway Sigma platform that can extend DPI and other data intelligence gathering and enforcement mechanisms into the cell itself—a new service Allot calls CellWise that it plans to demonstrate for the first time at CTIA Wireless next week. In practice, Allot has had visibility into individual cells for some time. Since July it has produced a Mobile Trends report, which provides detailed analysis of traffic trends on the a cell level extrapolated from customer data its platform gathers around the world. The Sigma gateway has always been able to sniff out the cell ID of any outbound or inbound packet, but acting upon that information is easier said than done, Gordon said.

The gateway has to identify the destination of data session in real-time, register against a network data base and then reference the overall capacity of the cell by monitoring the amount of data flowing through its backhaul connection. Then it must reference the policy control and charging function (PCRF) of the network to decide what policy to enforce on that particular session for a particular cell—and it must all be done in real time with interrupting the flow of traffic, Gordon said. Mobility adds the extra layer of complications as policies change dynamically as the dynamics of the network change, Gordon said. For instance, a customer entering a cell while viewing a video stream might suddenly find his bandwidth throttled back due to congestion on the cell, but as they move into another cell, that bandwidth restriction might not move with him, depending on the level of congestion in the neighboring cells. Conversely the same user staying put might find a bandwidth restriction lifted as other users move out of his cell. In a mobile network, there are a lot more parts to account for, and they are all—quite literally—moving, Gordon said.

Allot may be one of the first DPI vendors to extend its feelers into the cell site, but it’s not the first vendor to do so. Alcatel-Lucent (NYSE:ALU) released its Network Guardian platform almost two years ago and while it hasn’t been able to name many customers, the one it has revealed is a doozey: AT&T selected Network Guardian as its traffic management platform when it named Alcatel-Lucent as its 4G radio access vendor for long-term evolution. Like Allot’s platform, Network Guardian reaches all the way into the cell to determine each individual user’s impact on the network, but unlike Allot, ALU doesn’t use DPI technologies, which have become a controversial target in the net neutrality debates.

While conscious of the controversy around DPI, Gordon said it’s unfair to label Allot as a DPI company, while a company like Alcatel-Lucent escapes vilification. “DPI is one of the nine technologies we use to identify applications and subscribers,” Gordon said. It’s merely a tool in a fairly large tool chest to handle policy enforcement. ALU and other ‘non-DPI’ vendors are just using a different set of tools to accomplish the same tasks, he said. Ultimately DPI, the technology, and DPI, the ‘tactic,’ are two distinct things. Depending on how an operator uses it, DPI can be viewed as an equalizer, improving the mobile data experience for everyone, or as a gatekeeper, denying access to specific applications or classes of applications, Gordon said.

Either way, DPI is useful though limited tool—it can’t snoop into encrypted sessions, for instance—and when combined with other traffic management and enforcement techniques can have significant impact on the quality of experience on the network, Gordon said. Most of the wireless infrastructure suppliers have been incorporated some kind of traffic management solution into their hardware, whether it’s at the transport router or edge gateway, but by having a dedicated solution—not just an app running on a box—Allot’s platform will be able to handle far more complex tasks of real-time dynamic policy management, Gordon said.