Monday June 28, 2004

Java: your magic ticket to IPv6

A couple of weeks ago I was in L.A. attending the IPv6 Summit where I was scheduled to make a presentation about Java's support of IPv6. while there, listening to the other presenters I realized something. There is a gap, a disconnect, between application developers and the network infrastructure people. You see, very few attendees were developers, or ISVs, so it felt a bit like most presentations were "preaching to choir" so to speak. Most people in the room were convinced that not only IPv6 was important, but it was also inevitable. It will happen, and, actually it is happening. Many of them were actively involved in making it happen. So how come, when I talk to application developers, they don't seem to care one bit about IPv6 support? Even when their application is heavily networked.

I've been pondering that question for the past 2 weeks and I've come up with a few elements of answer.

First, and foremost, most developers don't know what IPv6 is all about, and when they do know a bit about it they seem to believe that we don't really need it, what with NAT (that's Network Address Translation in case you didn't know) and similar technologies. Second, to most of them, supporting IPv6 means "porting your application", like supporting a new platform that almost nobody is using. In today's market, it's like a death sentence. But it's also a catch 22 situation. You see, many ISPs says they're not deploying IPv6 because there is no demand for it (at least in the US), and there is no demand for it because there are no application for it either. We got a bit of a deadlock here. I'll get back to that later. First I want to address the first point.

Why do we need IPv6? I won't bore you here with all the technical reasons, you can read about it from a number of sources, including at the IPv6 summit website, in particular in the tutorial section, I'll just mention the main 4 ones:

• Address space
• auto-configuration
• end to end security
• mobility

The first one, of course, is the real kicker: with address length of 128 bits instead of 32, IPv6 makes it possible to assign an address to about any device ever conceived and still not run out of addresses. Couple that with auto-configuration and you won't have to worry about IP addresses ever again.

Now, I know what you're thinking: "NAT solved that problem already". Not quite so, for one thing NAT creates a lot of problems when it comes to end to end communication (think P2P for example), and already some organizations are running out of "private addresses" as defined in RFC 1918. Also, it is has been estimated that if the developing countries (China, India, etc...) get to the point where a mere 20% of their population has Internet access, then we would need 4 times more addresses than are left available, and that's taking NAT into account! So, we don't know when we're going to run out of addresses, but it could happen almost overnight! That's why Asian countries and the European community are pushing IPv6 very hard. On top of that the U.S. Department of Defense (DoD) as announced that they will switch their whole network infrastructure to IPv6 by 2008 and they issued a mandate that, since Oct. 2003, all IT equipment they will purchase, be it hardware or software, has to be IPv6 enabled or have a clear roadmap proving it will be in time. So, if the DoD is one of your customers you probably should worry about IPv6. Same thing is true when it comes to mobile devices, like cellphones or PDA.

So IPv6 is not only needed, it is happening, big time! And, you, developers, should get on the ball!

But, what does it mean to port an application to IPv6? Well, herein lies the "bad news, good news" cliche. The bad news is for applications written in C or C++ (or even C#) the porting can range from simple, for client applications on Unix, to total nightmare, for server applications on Windows (you see Microsoft didn't deem necessary to provide a proper dual stack implementation therefore their IPv6 is the only one I know that is not compatible with IPv4). In any case it means source code changes, new binary relying on new libraries, and, of course, new bugs! Bottom line a lot of work. So what is the good news, you ask? The good news is if you were smart enough to write your application in Java, then you don't have to do anything! You're done. I mean, your code is already IPv6 enabled, you don't even have to recompile. That's right: that application you wrote, and compiled, with JDK 1.1 in 1996 will work just fine on an IPv6 system if you run it with the proper VM (1.4+ for Unixes, 1.5+ for Windows). Let me rephrase that: Any java application (as in the exact same bytecode) will run on any platform whether it's IPv4 or IPv6, Linux, Solaris or Windows! You got IPv6 for free! Remember that the next time you have to convince your management that you should use J2EE instead of .Net for instance!

If you'd like more details about IPv6 and Java, I'd point you to the presentation I made at the IPv6 summit.

In any case, I'll be at JavaOne, so don't hesitate to look me out and ask me any question.

You can catch me at the "ask the experts" booth (don't laugh I didn't pick the name) on Tuesday from 10:30am to 1pm, then at the Technical session TS-2476 on Tuesday from 2:45pm to 3:45pm, and finally we'll have a BOF for Java networking Tuesday at 10:30pm (Esplanade 304/306, Moscone center). I hope to see you there.