Preseem is a Quality of Experience (QoE) monitoring and optimization platform developed for WISPs. This blog post highlights how traditional subscriber plan enforcement tools like Mikrotik simple queues or APs negatively impact subscriber’s Quality of Experience (QoE). 

There are many different ways to enforce subscriber plan speeds. So if a subscriber buys a 5 Mb/s plan, there are lots of ways to make sure that they only get 5 Mb/s of download plan speed. Some very popular modes to enforce subscriber plan choices in the WISP space are Mikrotik Simple Queues, Access point or CPE shapers. All these mechanisms do a good job at making sure that subscribers are getting the plan speeds they’re supposed to.

The problem, however, is how these systems achieve the prescribed subscriber plan limits and what happens to the Quality of Experience (QoE) of the subscribers at home once the plan speed is hit.

Traditional shapers like these have a single buffer for each subscriber’s traffic. Incoming packets go into the buffer and the buffer lets out 5 Mb/s of data on the other end. If more comes in than what goes out, the buffer starts filling up. As the buffer fills up, it adds latency to all the traffic in the home. Let’s say it’s something like Netflix that’s causing the buffer to fill up, this can add 10s or 100s of milliseconds of latency. For Netflix streaming itself, this filled up buffer won’t matter much in terms of user experience. However, the issue is for every other application in the home. Let’s say one person is watching Netflix in the home and someone else is doing a VoIP call or gaming or web browsing, packets for all other applications will sit behind the same buffer and cause a very sluggish user experience. Gaming will become laggy, browser will become slow, VoIP quality will go down and collectively, this will lead to a terrible network quality from the subscriber’s point of view. So from a WISP perspective, the subscriber plan speeds were enforced but from the subscriber’s POV, the quality of experience was bad and this generally leads to support/complaint calls. 

With traditional shapers applied, as soon as any one internet application maxes out the connection for a home, every other application in the household becomes slow and laggy. This is typical of a Netflix stream negatively impacting interactive applications like VoIP, gaming or web browsing.

Preseem solves the above subscriber plan enforcement problems associated with traditional shaping tools in two ways:

1. Instead of using a simple buffer that fills up as packets come in, Preseem uses Active Queue Management (AQM). AQM knows exactly how many packets to buffer or to drop and applies TCP signalling to get the heavy traffic to back off. The net effect is that instead of adding 150-200 ms of latency, Preseem adds less than 10 ms when it kicks in. Even if a subscriber is doing a big download (eg OS update) that causes the link to max out, the latency with Preseem is nice and low which ensures that the overall QoE is high and subscriber doesn’t complain.

2. Preseem further uses fair queuing to automatically distribute the bandwidth fairly between different applications. The way this works is that Preseem automatically figures out if an application qualifies as a ‘bulk’ flow or an ‘interactive’ flow. This is completely based on the size of the flow – how many bytes that flow is transferring. If it’s large, that’s a bulk flow or if that’s small, it’s considered an interactive flow. For every bulk flow, Preseem automatically creates one queue that manages that flow independently and it automatically balances or fairly divides traffic between those bulk applications. So, Netflix and a download for example will both get half the traffic. But any interactive flows like gaming or VoIP call and browsing – these flows don’t get queued at all. These smaller interactive flows get prioritized straight through.

So, no matter how busy a link is due to bulk applications like Netflix, interactive applications like gaming, VoIP call or browsing will always feel fast like there’s nothing happening in the link at all, thanks to Preseem’s advanced AQM and per-flow prioritization techniques. This leads to a much better experience for wireless customers.

Some of the obvious situations WISPs shared with us before Preseem was deployed, include:

  1. One household member watching Netflix in HD leading to a poor experience for another member of the house playing games
  2. On Windows update or iOS download days with maxed out connections, all other Internet applications in the house felt laggy and subscribers complained to their service provider about slow internet leading to lengthy support calls and high support costs
  3. Background download of heavy applications affecting overall internet experience in a large household leading to frequent complaints.

Users in all these situations reported better QoE after Preseem replaced traditional shaping and plan enforcement methods across WISP networks.  

Quick Case Study

subscriber plan speeds enforcement WISP Preseem

The above shows the latency and bitrate at a WISP with over 2500+ subscribers based out of Amarillo, TX. In this network, the plan rate was enforced at the access point (AP). Very similar results are found with Mikrotik based shaping.

Once the plan speed of 3 Mb/s was hit, latency for the subscriber shot over 200 ms. 50 ms of that was the Access point itself (base latency) with at least 150 ms being the buffer for the traffic management. As soon as Preseem took over the shaping for this network, total latency came down to around 55 ms with Preseem adding <10 ms of latency. This lower latency is a result of Preseem’s use of AQM techniques, based on FQ-CoDel, which ensures that the overall QoE for a subscriber remains high despite a maxed out connection/link.

To find out how your traffic management and subscriber plan enforcement tools impact subscriber QoE and how you can fix this problem, contact us for a free 30-day trial of Preseem.

If you like this post, please help us by sharing it with your network by using the icons here