Recently we’ve seen some players experiencing significant network issues across multiple regions, in particular US East and Europe West. We thought we’d take a moment to update you on what we’ve been doing in this space, because it’s such an important issue.

These kinds of problems generally stem from either limited server capacity or poor network connectivity. In this case, the problems are entirely connectivity related, and they come in three different forms – two of them are related to DDoS, and one is ISP connectivity.

The first, DDoS attacks on an entire data center for a region, are particularly problematic because they saturate the entire connection into the data center. This is a very recent type of attack that has been plaguing a variety of high profile games. It causes players to freeze up or drop entirely because as their network packets reach the data center, the link has no room to accept them and they are dropped. In the short term we are forced into being reactive to these attacks on a case by case basis, while building out a long term infrastructure to bring better stability and protection.

The second, directed attacks on a single server, is one that we’ve released various fixes for over the past month. These attacks largely targeted pro players or tournaments. The primary problem in those cases was the ability for an attacker to pinpoint the exact IP address of the target game server, which allowed them to successfully attack it with a small set of resources. We’ve recently updated Dota 2, Dota TV servers, and Steam itself to better protect that IP address. We have also improved the local lobby system so it can function as a better fail safe for tournaments, in case the IP address leaks out through other means, such as human error or third party software.

The third, network connectivity issues, result in some players having continuous networking problems between their ISP and our game servers. For quite a while this has been most visible in the South East Asia and South America regions, but does exist with other ISPs around the world. Finding the right solution with every region, and its local ISPs, requires us to have more detailed data on exactly why our players are experiencing these issues. So, this week we’ve finished implementation of a more advanced network monitoring system that will automatically gather much deeper connectivity data from all our players.

Good networking connectivity is a requirement for a good Dota 2 experience. While we work on the core problem, we’re also working on reducing its effects – this week’s update includes improved detection of Poor Network Conditions. Previously, our detection algorithm was only triggered when multiple players completely lost connection to the game server. This new algorithm will now monitor the actual quality of the server’s connection to its players, and trigger in the case of poor connectivity for multiple players. Matches flagged as having Poor Network Conditions will be immediately safe to leave, and won’t record their results.