Olivier Langlois's blog

In the last few days, I have read a press release announcing the upcoming release of the latest Harmonix game, Rock Band. The press release was, among other things, enumerating the merits of the online aspects of the game and one sentence did catch my attention:

The game will also make use of Quazal's Net-Z technology "for enhanced connectivity."

As having being the lead programmer of Net-Z for about a year before resigning last June, I have been wondering what "enhanced connectivity" was meaning. At first, it did just sound like a meaningless marketing buzzword as the press release do not elaborate on what it means and I could not think about any new features that would make Rock Band connectivity better than any previously released game using Quazal Net-Z network engine but now I think that I know what this sentence is referring to.

In order to understand what this enhanced connectivity is, you must understand how online games usually work. People connect to a lobby server to find online opponents. Once all participants are gathered together and ready to play, the lobby server will send the IP addresses of all participants to everyone. Upon the receptions of all IP addresses, the game will try to establish a connection to all participants to form a peer to peer network. A problem can arise because people are usually behind NAT routers and NAT traversal will be performed by the game. There exist 3 types of NAT routers. These 3 types of NAT routers are: open, moderate and strict. Someone behind a strict NAT router will not be able to connect to the other players with NAT traversal.

The last feature that I have been working on in Net-Z is the possibility to use a relay server (which could be the lobby server) as a fallback method for people behind a strict NAT router. What I am not sure is whether this "enhanced connectivity" will be available on PS3 and on Xbox 360.

Sony let pretty much developers do everything they want for the Networking aspects of their games. The only requirement that I am aware of that Sony imposes to game developers is that they do not have the right to ask to the player their username/password. Authentication must be done with Sony authentication servers.

However, Microsoft imposes a lot more restrictions. The only exception allowed by Microsoft to operate outside Live network is if a feature is not doable through Live services. Leaderboards are an example. Live could not support the amount of leaderboards that Harmonix wanted for Rock Band so they have been allowed to let Quazal host them. Did Microsoft allowed a Live game traffic to go through a 3rd party relay server for "enhanced connectivity"? That is an answer that I do know...