Feb 1st, 2011: Bye bye IPv4
Today, the IANA has allocated the last two remaining IPv4 address blocks to APNIC, the registry for the Asia/Pacific region. This means that the remaining five blocks will be distributed according to the “Global Policy for the Allocation of the Remaining IPv4 Address Space” evenly amongst the registries. And we’re out.
IPv4 will remain forever
This does not mean that we have NO IPv4 addresses, there are plenty. And the addresses you have won’t be taken away from you. You can still get addresses from RIPE, ARIN and the other registries if you really need them. The clue is in the last part of the previous sentence. You have to prove that you need them and that you will start using them immediately. If you get IPv4 addresses for your services from a hosting provider, getting new addresses will get expensive soon.
IPv6 is the Internet growth path
IPv4 can no longer handle the Internet growth. We will have to start using IPv6 for new services and applications, and new Internet connections. Otherwise, everyone will be behind large NAT servers. Not good for applications, not good for users and not good for performance.
What to do?
The panic is not in the network, your servers and services will continue to run. The panic is in the lack of knowledge and experience of IPv6 in your team. You need to put pressure in starting to work with IPv6 on all fronts, implementing it as a natural part of every project. Regardless if it’s about cloud services, unified communication, web sites, business support systems or e-mail. IPv6 needs to be there and you need everyone to accept that it’s a network just as natural as the IPv4 networks they are used to and know how to work with.
Dual stack solutions – good or bad?
When you start learning about IPv6 you can find a lot of old information out there. The protocol has been around more than 15 years and have changed. In those days, the concept of computers with dual stacks was a common thing. We used a PC-LAN network stack (IPx, netbeui, Arcnet, 10net) alongside the TCP/IP stack. And there was still a lot of IPv4 addresses around. The concept of dual stacks – one with IPv4 and one with IPv6 was launched as a natural way to migrate. After all, network engineers was used to handling dual stacks.
The world has changed. Network engineers have used single stacks for a long time. And the old dual stack concept was not shared by the same applications. In this dual stack world, with two IP stacks, applications are supposed to use both stacks, which causes a whole new set of issues. And we’re running out of IPv4 addresses, so we can’t assume that all new hosts will get proper addresses.
I strongly think we have to start adding hosts with IPv6 only, and start preparing the architecture for living with two networks. In many cases, an IPv6 only network with the support of NAT64 is easier to handle than a dual stack network. I think we’re beyond the point where dual stacks is the solution for all computers that we will attach to the network.
IPv6 – from snail-pace to VIP lane
The good thing is that even with dual stacks, IPv6 will be the better choice. Today, IPv6 is often implemented with tunnelling solutions, which means that connections have lower performance over IPv6. As we move along and implement non-tunnelled IPv6 in the networks, users will notice that IPv4 will be hidden behind multiple layers of NAT and IPv6 will be the faster network to use. Applications should make the preference a user configurable option, not something hidden in the application.
To summarize:
- The global pool of free IPv4 addresses has been distributed to the registries today, making the global pool empty
- IPv4 will remain, but will not handle Internet growth
- You need to make IPv6 part of regular work, not a special project
- Use dual stack for public services, but do not assume it for every host on the Internet
Today is the beginning of the next phase of the Internet. Don’t miss this phase and lock yourself and your organization into the old network.
/Olle E. Johansson
Finally an RFC for the SIP INFO message
SIP, like HTTP, is a request-response protocol. Each request has a method, that is standardized. A call setup uses the INVITE method, a call tear-down (hangup) use the BYE method. Those are simple to understand, as are a few of the other ones, like REFER for call transfers and MESSAGE for SMS-like text messages. The SIP INFO method has been an unspecified area used for left-overs from the SIP meal. A number of usages has been established. The new RFC – “Session Initiation Protocol (SIP) INFO Method and Package Framework” (RFC 6086) tries to clear up the kitchen and organize the dishes to continue the metafor. Read more
Asterisk: Distributed states using SIP
Asterisk was originally built as a stand-alone system, a single central point for all telephony communication. In short, a PBX. Nowadays, the Asterisk Open Source telephony server, is used in many ways – many of them not really being PBXs. All kinds of applications are being powered by Asterisk.
While building applications with Asterisk, you soon realize that you’re limited to that single server. It’s hard to scale and one limiting factor is that the call state is being held in one server. Many services depend on call states – if an agent in a call center is busy, you need to find an available agent. If a trunk to the PSTN is in use, you might want to find another way out. Call states are important.
Of course, the Asterisk project is now working on the long term solution, the Asterisk SCF and the applications that will be built using this framework. But that will take some time. Meanwhile, the Asterisk PBX team has been working on a few ways to distribute the call states between a group of servers. This article will be describing a few of the different architectures being worked on. Read more
The Realtime Cloud – unified or isolated islands on the net?
Here’s a copy of the presentation delivered by Edvina’s Olle E. Johansson at the Telecom Management Association’s Cloud Computing Congres in Utrecht, the Netherlands in December 2010. Read more
IT-center awarded for Portuguese University project
IT-center, one of our partners in the Open Unified Communication Alliance has been awarded the Digium Innovation Award 2010 at Astricon in Washington DC this year. Congratulations!
Digium writes:
“The 2010 Digium Innovation Award is ITCenter, located in Santa Maria da Feira, Portugal. Since 2003, ITCenter has differentiated itself by specializing in innovative solutions based on open source technologies, including Asterisk. ITCenter used Asterisk to interconnect all 48 Portuguese Higher Education & Scientific Institutions, integrating 220 existing legacy PBX systems and enabling VoIP communications between all the institutions without any change to its existing phone systems. The implementation provides centralized management and billing of both the legacy and new system, while supporting an infrastructure that processes approximately 7 million monthly calls.”
They got the award for the project that Edvina, IT-center and Wavecom built for the Portuguese universities. The platform is now running in over nearly 50 universities, on over 500 servers and handling over 100.000 phone lines for employees.
The solution is based on Asterisk and Kamailio servers, with FreePBX as the core PBX engine. Edvina built the SIP architecture and also added many new functions to Asterisk in this project.