The Need for a WISP Bandwidth Control or Traffic Management Solution
Whether its optimizing use of backhaul capacity or selling plan speeds based on customer needs, almost all WISP owners or operators need a bandwidth control solution. Some WISPs refer to bandwidth control solutions as traffic shaping or rate limiting while others call it plan enforcement. Beyond the terminology, the importance of an effective WISP bandwidth control solution cannot be understated.
Subscriber needs vary. As a result, most WISPs sell plans with speeds like 10 Mbps down and 1 Mbps up for small families. And, 25-50 Mbps or more for gamers and heavy video streamers or downloaders.
From an enforcement perspective, many WISP owners and operators think that as long as they have a bandwidth control or management solution that limits the customer to their speed and plan, that’s enough.
However, in reality, there’s a lot more to WISP bandwidth control solutions than the simple ‘enforcement’ aspect. More importantly, how WISPs rate limit or ‘enforce’ their subscriber plans has a large impact on the customer experience.
How WISPs Enforce Bandwidth or Rate-limit Customers Matters a Lot
Almost all WISPs enforce subscriber plans. The choice of a WISP Bandwidth control or traffic shaping solution has a direct impact on subscriber’s Quality of Experience (QoE). Poor plan enforcement leads to the typical ‘my-internet-is-slow’ calls. Generally, when a customer calls in with such a complaint, it is often the case that they are downloading the latest windows updates, using many Netflix streams or otherwise hitting the bandwidth limit of their plan or connection. This doesn’t have to be the case. This bad QoE is the result of using poor plan enforcement techniques.
Many WISPs deploy one of the following three WISP bandwidth control methods. While each does a good job of basically limiting customers to their plan speeds, their impact on QoE is often not understood or underrated by WISPs.
1. Access Point (AP) Enforcement
Most AP hardware allows the WISP to set per-subscriber bandwidth limits directly on the AP. AP bandwidth shaping tools use simple queueing techniques. With simple queues, if more data comes in than what the queue can handle, packets are either dropped or buffered. This can lead to bufferbloat problems or the typical ‘my-internet-is-slow’ complaints when users try to watch streaming video alongside other users playing online games or making a Skype call. In most cases, this leads to a very poor subscriber experience and complaints that require costly customer support or site visits.
Bottom line: AP-level shaping tools use simple queuing techniques which allow heavy/bulk applications like streaming video (for example, Netflix) to negatively impact the performance of smaller/ more interactive applications (like Gaming, VoIP, and DNS queries). So if a household is streaming video and they max out their plan speed, all other applications/users will suffer.
Some WISPs use scripts or rules set in their edge routers (like a Mikrotik) or Customer-premises equipment (CPE). Due to hardware limitations, these platforms also use simple queuing techniques which let heavy applications negatively impact the performance of interactive applications. Similar to AP-level enforcement, router-level traffic enforcement or shaping is incapable of subscriber-aware policies such as multi-site bandwidth limits.
Bottom line: Router or CPE level shapers use simple queuing techniques allow heavy applications like streaming video to negatively impact the performance of interactive applications.
3. Application-Aware (DPI-based) Traffic Management Tools
Some network managers choose solutions that inspect individual applications. Further, such solutions use a complex set of rules to treat individual traffic flows differently and set individual priorities. In such a case, a WISP will set manual rules like capping Netflix traffic at ‘x’ Mbps, VoIP at ‘y’ Mbps and so on. DPI-based solutions require constant tweaking and upgrades to try to stay current with the rapid change in applications on the Internet. Also, setting arbitrary bandwidth limits is inherently complex and time-consuming. For example, it’s impossible to know the appropriate rate to shape Netflix as it varies with the video encoding, content (eg action movie vs. cartoon) and even the type of the device that is playing the content. Worse, setting these values wrong can make the subscriber QoE worse than having no bandwidth control solution at all. Furthermore, with an increasing amount of encrypted traffic, DPI-based bandwidth control solutions have declining utility.
Bottom line: DPI-based application-aware solutions most often use simple queue techniques and are inherently costly, operationally complex, require constant tweaking and have declining utility given the rise of encryption.
There’s a Better Way When It Comes to WISP Bandwidth Control Solutions
When it comes to effectively managing bandwidth and enforcing subscriber plans, there’s good news for WISPs. Much progress has been made in the field of active queue management (AQM) and internet traffic management over the past five years or so. One recent innovation coming out of the IETF (Internet Engineering Task Force) is FQ-CoDel. The FlowQueue-CoDel (FQ-CoDel) algorithm is a combined packet scheduler and AQM technique developed as part of the bufferbloat-fighting community effort that is application agnostic (doesn’t care what application the user is using).
In this approach, flows are automatically categorized into bulk or interactive based on how much queue they build up. So applications like streaming video or Netflix (Netflix isn’t really a stream) get categorized as bulk flows. On the other hand, VoIP, gaming or DNS queries that are latency sensitive get categorized as interactive flows. Further, interactive flows get instantly prioritized. As a result, even when a customer maxes out their plan with Netflix or other heavy downloads, the other applications don’t feel slow. The overall experience is much better. The following image helps illustrate this.
Preseem QoE Optimized Bandwidth Control for WISP: An Easy and Effective Traffic Shaping and Plan Enforcement Solution
- Keeps just the right amount of queue in the device to ensure high link utilization and low latency
- Ensures per-flow fairness and prioritization (interactive flows get implicitly prioritized to the front escaping any impact of bulk applications)
- Requires no complex policies, arbitrary rules or encryption concerns
WISPs that deploy Preseem’s QoE optimized shaping (based on FQ-CoDel and AQM techniques) get:
- Happier Customers
- Lower Churn
- Fewer Support Calls
- Fewer truck rolls/ support costs
- Better bandwidth utilization
- Delayed network investments or upgrades
Hundreds of fixed wireless networks deploy Preseem’s QoE optimized bandwidth control solution today! Check out some of our video reviews and testimonials here.
For more information on Preseem’s QoE monitoring and optimization platform, click here to book a demo with us.