Common Connection and Latency Issues - PC/MAC

FAQs

Why am I only having connection problems with Blizzard Games?

There are a lot of potential causes for this. Bad data in your game files can cause both connection problems and crashes. Certain programs may fight with the game client for control of your network drivers, or eat up so much bandwidth that the connection to the game servers may be slowed or disconnect. To add to all of this, everything else that you connect to across the internet is in a different physical location. Even two different data centers in the same city may use different peering partners to connect. It’s very likely that you take a different path through the internet to connect to our servers, and so comparing two games or services is most likely not relevant. If there are any problems between your house and our servers, you’ll usually need to reach out to your ISP to get them resolved. (This is why we ask for connection tests when you’re having particularly stubborn connection problems.)

There is always the possibility that there is a server issue, but we try to post about these problems on the Breaking News bar on the Blizzard Application and In game, and update our BlizzardCSEU_EN Twitter channel as soon as we can. If you suspect this is the issue, check those locations first before trying troubleshooting.

I have a high speed connection, so why is my latency so high?

When your ISP advertises connection speed - they are talking about bandwidth. Bandwidth is a measure of how quickly data can be downloaded and uploaded. If you imagine data moving like water flow, a high bandwidth connection is like having a wide pipe for the water to flow into your house instead of a tiny one. As long as there’s enough pressure, you can get a lot of water really quickly like this.

Latency on the other hand measures how quickly you receive information, no matter your bandwidth. In this metaphor, high latency would be something causing the pressure to drop. Maybe you’ve got a good pipe going into your house, but there’s a leak somewhere in the city water supply, or a clog in a pipe feeding your apartment complex. You still have the ability to receive as much data as advertised, but you aren’t because there’s something delaying the flow of that information. When we investigate high latency, we have to find out what’s causing you to get your information slowly.

Why do you suggest that I disable security software like antiviruses and firewalls as a troubleshooting fix when they were working with the game previously?

This has to do with how often both our games and security programs are updated.
We like to release lots of patches to fix bugs and add more content for you to enjoy. Antiviruses and firewalls also like to release lots of definitions updates to keep your computer more secure from the latest threats. The problem happens for one of two reasons. Sometimes our updates cause the security to mistakenly think our games are a threat. In other cases, a particular build of our games will get mistakenly added to the security’s list of ‘bad’ programs. This may mean that you just accidentally clicked ‘no’ to a security prompt to allow our game to connect, or that the antivirus just flagged our game incorrectly as a malicious program. Updating your security programs and disabling or uninstalling them when that fails can help rule this out as a possibility.

Why can I stream or download from other sites without issues but have problems in certain games?

There are two parts to this. The first is that streaming services have the ability to buffer information. This means that they give your computer data before you see it, often 30 seconds or even minutes before you need to look at it. Online games on a ‘live world’ (Like Diablo III) need to give you data immediately so that you can react to it immediately. After all, you seeing old data in a hardcore greater rift would probably mean your character would be dead before you saw it. Where downloads are concerned, a direct download can be interrupted and pick back up once your connection returns in most cases. Diablo III will try to do this, but if you disconnect for too long, you will be fully dropped from the servers.

The second bit is “try disabling those sorts of services first if you find that you’re having connection problems.” Anything that takes up bandwidth may cause connection problems (or make connection issues worse even if they aren’t the main cause.)

Why do I need to swap to Ethernet when my WiFi works for other things?

Most of this is covered in the previous question’s answer, so make sure to review that first. Because WiFi is by nature less stable than a wired Ethernet connection, these types of problems are made even worse. Many things can interfere with WiFi, from physical barriers (walls, glass, etc) to other types of waves (microwaves, etc), to computer power issues. WiFi and USB WiFi hardware are also more prone to failure over time than an Ethernet cable is in most cases. Unless you physically damage an Ethernet cable or Ethernet port, usually they will work well for the lifetime of your PC/Router. A WiFi transmitter or receiver is more complex and may degrade over time. The easiest way to see if your WiFi devices are the problem is connecting directly to your modem or router via Ethernet. If it resolves your issue, there are other troubleshooting steps you can try. Note that we do not directly support wireless connections, so you may want to ask the community at this forum for help optimizing a wireless connection if you find your WiFi is at fault.

Why is my entire internet crashing when I disconnect from Diablo III or Blizzard Games?

This usually indicates a local network issue. When your internet goes down, it most frequently means that your network drivers or firmware crashed, or a piece of hardware was overloaded with information. If you have this sort of problem, the things you want to focus on first are hardware related. That means:
• Driver and firmware updates
• Power cycling your connection hardware
• Switching to an Ethernet cable connection
• Bypassing or replacing network hardware like routers and modems.

(These steps are covered in more detail at this link) You may need to contact your ISP for more help if the problem continues.