Lag, high ping and packet loss have plagued a lot of Dota players as of late, both in public games as well as tournaments. Just a couple of hours ago, Valve released a network update alongside a blog post, explaining the situation and promising change.
Over the last couple of weeks, spectators and players experienced a lot of pauses in tournaments, as lags was frequent and packet loss became an atrocious problem. Not only public games suffered from this, but more importantly tournaments experienced a lot of problems and delays. Valve now pinpointed the network issues down to three different forms:
DDoS attacks on an entire Data Center
It appears that this has been a quite frequent problem as of late, as certain groups of people try to shut down an entire data center with their DDoS attacks. This proves to be problematic for players, as the server is simply unable to accept their network packets, which then get dropped, causing games to freeze and players to drop out. Valve promises to try and build a long term solution for this, but has to try and operate on a case by case basis for now.
[...]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.[...]
DDoS attacks on a single server
As if it wouldn't be enough that entire data centers suffer from DDoS attacks, it appears that there is a way to target a game server directly. By pinpointing the exact ID of the game server, it was possible to wreak havoc with only a small set of resources. For this issue, Valve has released a series of fixes to try preventing further issues.
[...]The second, directed attacks on a single server, is one that we’ve released various fixes for over the past month.[...]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.[...]
Network Connectivity Issues
The third problem seemed to be a result of a weird interaction between the players ISP's and Valve's gameservers resulting in continuous networking problems. This problem has been most visible in South East Asia and South America, but was experienced by players all around the world. As this appears to be a more local problem, Valve will implement tools to gather more data, on what exactly causes the issues.
[...]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. [...]
Additionally to all the aforementioned changes and fixes, Valve also changed their algorithm to define whether a game is experiencing poor network conditions to reduce the effects of lag and packet loss on public games.
[...]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.
