For comparison, in this article, we selected mid-level devices from the most popular manufacturers as the best-selling and most used ones. Usually, only large operators can afford the top devices. These ISPs either already use solutions from one of the manufacturers, or they order the implementation of the system from an integrator according to their technical specifications.
Devices from different manufacturers work on different hardware platforms and with different software. It is necessary to take into consideration that the characteristics of the products are flexible: each line has different solutions in terms of power. Each platform is selected according to the project specifications, which may contain details that could narrow down the final choice to 1-2 solutions. For example, the ISP can decide to combine DPI and CGNAT systems in one device — this is what VAS Experts SSG corresponds to. And if the network is built based on Cisco ASR, then it is possible to implement an AVC solution without investing additional equipment.
Midrange devices are almost identical in their performance and technical characteristics. It’s important to consider that each additional module for Allot and Sandvine is quite expensive. Also, if you would like to increase the performance, then you will need to expand the license as well.
However, there is a downside. A solution on proprietary hardware platforms makes the finished device more reliable and stable, even if it’s based on a basic x86 processor. You can compare this to Apple’s iMacs with macOS and a regular Windows PC. The Apple PC is more productive and stable than a similar solution on Windows because of the unified platform and optimization of the operating system for certain hardware.
Features of DPI manufactures
It is a great advantage if the manufacturer can provide equipment for testing. More often you would have to defer to the experience of the other ISP’s who have already implemented and are using the system. Of course, every manufacturer will tell you that their device is better than the others. But if you would make a list of specific technical questions and ask them to support it, then you could get the full idea of the product.
For example, Sandvine presents and provides support only via an integrator, but they frequently update platforms’ software and allow flexible customization. Their PacketLogic platform is famous for a user-friendly configuration and maintenance client, as well as excellent visualization of the functions performed.
Cisco’s solution can have a bandwidth limit of 15 Gbps per Service Control module, but the Subscriber Manager feature requires no additional licenses and is included as a basic feature. VAS Experts manufacturer updates the SSG software to fix bugs regularly, adds new protocols and signatures. It’s good that new signatures allow detecting types of traffic in more detail. On the other hand, fixing some bugs may contribute to the appearance of new ones, so the system requires adjustments.
Approximate calculation
Performance, features, and usability are very important factors. But the fundamental decision to integrate a DPI system depends on OPEX (operating costs). Here is a calculation of financial effectiveness (ROI) from the implementation of the traffic management system Stingray Service Gateway.
| Number of subscribers | 15 000 |
| DPI solution cost | from $50 000 |
| The proposed efficiency of DPI solution | 20% |
| Cost for 1Gbps | $3 000 / month |
| Average speed by data plan | 50 Mbps |
| Average Bandwidth utilization per subscriber | 15 Mbps |
The traffic consumed by the subscribers is: 1,5 Mbps * 15,000 = 22,5 Gbps per month. Using a DPI system with a claimed uplink reduction efficiency of 20% gives us 4,5 Gbps of bandwidth savings per month (15 Gbps * 0.2 = 4,5 Gbps). Monetizing the 4,5 Gbps savings * $3,000 = $13,500. At this monthly savings, the recoupment on the DPI implementation would be only 4 months ($50,000 / $13,500 = about 4 months).
This calculation allows you to estimate the approximate benefit of using the SSG solution. And you also should count that the implementation of additional functions such as access limitation to resources, protection from DDoS attacks, CG-NAT, BRAS from VAS Experts will not require extra investments. So the payback period will be significantly reduced. At the same time, the quality of services provided to subscribers will be higher for the same subscription fee.