Veteran Network Coder Provides Troubling Analysis Of The Division's Problems

The Division was a massive success from a sales perspective, toppling Ubisoft's first-day sales record. However, several problems have sprung up related to hacks and cheating in the time since launch. Some issues have made it to consoles, but the PC version is the platform most affected. With the complaints becoming louder and louder, one veteran network coder attempted to analyze the issues Ubisoft's multiplayer shooter faces. According to Glenn Fiedler's recent post on his blog Gaffer on Games, it may be more difficult for Ubisoft to fix the issues than some may think.

Fiedler, whose credits include Titanfall, Journey, and the God of War series, says that signs point to Ubisoft using what is called a trusted client network model. If that is indeed the case, it means that every action from players is tracked by a client rather than the server, and that the server trusts that the client's input is valid. This enables hackers to take advantage of client-side hacks, as the server trusts whatever the client tells them is happening, and then portrays that impression to the rest of the players on that server. This puts an enormous amount of power in the hands of hackers and creates a massive headache for the developers trying to fix it.

If Ubisoft and Red Storm Entertainment are in fact using a trusted client network model, it shows a fundamental misunderstanding of the standard way to set up a network for a "top-tier" shooter according to Fiedler. "What top-tier competitive FPS games actually do is actually quite different," Fiedler says. "For a competitive first person shooter there is a pretty standard approach to networking pioneered by Quake and later on perfected by Counterstrike. This is the same network model used today by top tier FPS games like Call of Duty, Overwatch and Titanfall."

According to Fiedler, most triple-A shooters use clients to protect you against lag on your own actions as well as generally protect you against things like you not getting credit for what appears to be a successful hit on an opponent because of lag on their end. What Fiedler says is critical is that those successful hits should be decided on the server, not on the client. The most important idea is that the server should not trust the client to the extent that it takes a player's actions as truth to the point where it affects the experience for other players. This includes the server not trusting the client on things like player movement and positioning, successful hits on opponents, fire rates, ammo counts, and inventories.

Fiedler says that if The Division is actually using this model, it could spell extreme problems for the development team in trying to fix to the issues; it could even mean that a complete rewrite of the game's netcode is needed to completely patch the system. "If a competitive FPS was networked [...] with client trusted positions, client side evaluation of bullet hits and 'I shot you' events sent from client to server, it’s really difficult for me to see how this could ever be made completely secure on PC," he says.

While these critiques were focused on the PC version, Fiedler says that the console version could potentially be an easier fix if the developers fix issues related to lag switch timing.

We have reached out to Ubisoft for comment on the accuracy of Fielder's analysis, but we did not immediately receive a response. Should we hear back, we will update this story.

[Source: Gaffer on Games via Eurogamer]

Our Take
If Fiedler's analysis is true, this could have catastrophic implications for The Division and demonstrate a fundamental misunderstanding by Ubisoft and Red Storm on the industry standard best practices for netcode and network models. It's possible that Fiedler is incorrect in his analysis, but given his experience in the industry, I'm more inclined to believe he knows what he's talking about. Just like Fiedler, I'm rooting for the developers behind The Division to fix the issues that have become more and more commonplace, but after reading this analysis, I don't know how confident I am.