(NOTE: Need to include reference here to how WebRTC is designed to work with IPv6.)

Documentation

• RFC 6197, “IPv6 Transition in the Session Initiation Protocol (SIP)”

Presentation Slides

• IPv6 and SIP – Myth or Reality?  (SIPNOC 2013 – April 24, 2013)
• SIP and IPv6 – Can They Get Along?  (SIPNOC 2012 – June 26, 2012)

Communities

There is a good amount of discussion about IPv6 happening in various IPv6 communities around the Internet. More specific discussion about IPv6 and IP communications is happening here:

• SIP Forum IPv6 Task Group mailing list (open to the public)
• SIPv6 Facebook page and Twitter account (projects started by Olle Johansson)

Softphones

We are aware of the following softphones that support IPv6:

• Jitsi (open source) – see our interview with project lead Emil Ivov
• Linphone (open source)
• Counterpath Bria  (commercial)

Communications Equipment

Beyond softphones, we are aware of the following equipment that supports IPv6.

(NOTE: Links need to be added, ideally to IPv6-specific pages. Also, it is worth considering whether this list should be moved to a separate page.)

IP Phones (Desktop):

• Avaya (unclear on exact models)
• Mitel 53xx Series
• Mocet
• Siemens OpenStage
• Snom
• Yealink SIP-T2x

IP-PBXs/Call Servers:

• Asterisk 1.8+
• Brekeke SIP
• Cisco Unified Communications Manager 7.1
• Freeswitch 1.1+
• Kamailio 3.1+
• Microsoft Lync Server 2013
• OpenSIPS
• Voxeo Prophecy and PRISM

Other SIP Devices

• Cisco SIP Gateways ( ISR 28XX & 38XX, AS5400 )
• Dialogic SBCs
• Mediatrix
• Mitel Border Gateway (MBG)

SIP Services (in the cloud)

• INUM.net

Additional resources will be added to this page as we become aware of them.

Know of additional resources related to IPv6 and IP communications that we should list?  Please let us know!

One week from today, on January 9, the SIP Forum’s “SIP Over IPv6 Task Group” will be having it’s next conference call.  Andy Hutton, co-chair of the group, provided notes of last call where discussion continued about how to move efforts forward.  As he notes, a message with an agenda and more details should be sent to the list soon (you can check the list archive).

As I wrote about before, this Task Group is an important step toward getting more Voice over IP (VoIP) communication happening over IP.  If you are interested in getting more involved, the Task Group web page explains more about what the group is doing – and the SIP Forum IPv6 mailing list is open to all to join.

To that end, my slides about SIP and IPv6 are now available online for your viewing and/or downloading.  I did record the event on video – and at some point here I’m aiming to publish that to our YouTube account.  Meanwhile, enjoy the slides…

I’ll be exploring all those questions and much more at the “SIP Network Operators Conference (SIPNOC)” next week in Herndon, Virginia, USA.  SIPNOC is a great event sponsored by the SIP Forum that brings together network operators and many other companies all involved in actually deploying and using SIP for voice over IP. I really enjoy the event as the participants are really on the leading edge of IP communications. This year, too, the CTO of the US Federal Communications Commission (FCC), Henning Schulzrinne, will be giving what should be an interesting keynote. (And it’s not too late – you still can register to attend SIPNOC!)

As noted on the agenda, I’ll be participating in three sessions during the two-day event:

Tuesday, June 26

10:30am-11:15am: Panel Discussion: SIP Adoption and Network Security.

Along with Eric Burger of Georgetown University (and also an Internet Society Board of Trustee) and Randy Layman of Vocalocity, I’ll be discussing VoIP security issues, a topic I’ve long been involved with.

11:45am-12:15pm: SIP and IPv6 – Can They Get Along?

My main session for the event. The abstract is as follows:

With World IPv6 Launch happening June 6, 2012, production IPv6 network connectivity will be available to many more businesses and individuals. Major web sites and content providers will all enable IPv6 access to their content. Consumer electronics manufacturers are committing to providing IPv6-enabled devices.

What does this mean for SIP-based real-time communications? How well does SIP work with IPv6 today? What are the challenges to deployment and what steps can be taken to overcome those challenges? What should operators and vendors consider with regard to SIP and IPv6? What software, devices and tools are available to assist? And what case studies and other information is available?

In this session Dan York will discuss all of these points and provide concrete suggestions for moving forward with SIP and IPv6. The session will also provide time for sharing of experiences and insight of the attendees. Please bring your questions, ideas and be prepared for a lively session looking at how SIP and real-time communications can work in the new IPv6-based Internet.

We’ll post slides and hopefully video after the event is over.

Wednesday, June 27

12:45pm-1:30pm: BoF: SIP and IPv6

This will be an open forum for discussion of SIP and IPv6-related issues.  At last year’s SIPNOC event the session was very well attended and there were great discussions about issues people were having, examples of where IPv6 worked well and questions people had about tools and services.  I’m hoping we get that level of participation again and that it can be a useful learning experience for all involved.

If any of you will be attending SIPNOC I look forward to meeting up with you there.

jitsi.org

Jitsi has a great range of features including support for voice and video calls, chat/IM, desktop sharing, conference calls, wideband audio and much more. It works with the SIP (Session Initiation Protocol) and XMPP (Jabber) protocols and connects to common services like GoogleTalk, AIM, Yahoo!Messenger, Facebook chat, etc.  It’s also free and the source code is all available.

Jitsi has supported SIP and XMPP over IPv6 for quite some time now, but with this new release adds support of DNSSEC courtesy, I learned, of some funding from the NLnet Foundation and the University of Applied Sciences and Arts Northwestern Switzerland (FHNW). The DNSSEC code itself was implemented by Ingo Bauersachs from this university.

Essentially what Jitsi now does if you enable DNSSEC is to validate the signing of the SRV records in DNS that provide the address information for the remote end of the SIP or XMPP connection.

To step back and explain a bit further, if Alice wants to call Bob (to be cliche), and she knows his SIP address is “sip:bob@example.com”, her SIP client, IP-PBX or other SIP server (depending upon configuration) is going to perform a DNS lookup on “example.com” to retrieve the relevant SRV records. These records will provide the IP address(es) of the SIP server on Bob’s side. Alice’s SIP software will then connect to those IP addresses to send the appropriate SIP INVITE to start a conversation with Bob.

But how does Alice’s software know that the SRV records retrieved from DNS are correct? How can it know that they were not tampered with?

What if she is trying to call her bank and an attacker is redirecting her to another SIP server where there is a similar call center or IVR? (Okay, leaving aside the fact that at this moment you may not be able to make SIP connections to many banks… but that is changing slowly.)

Enter DNSSEC.

If the “example.com” domain is signed via DNSSEC, including all the SRV records, then the VoIP client can validate that the SRV records are in fact correct and the connection can be made knowing that it is to the intended recipient based on the SIP address.

From a configuration point of view, there has been one more screen added to Jitsi’s preferences:

At this moment there is no documentation on the Jitsi site about the DNSSEC features (they are working on it… and open to any offers of assistance! , but I asked Ingo Bauersachs about the configuration of the resolver. His reply was this:

Libunbound, the library Jitsi is using, is validating the DNSSEC chain, but it’s not a full resolver. Queries for DNSKEY, DS, etc. are sent to the OS’s resolver, or if configured, to the “Custom name servers”.

The option to override the OS’s default resolver is there because during development, the only servers supporting all relevant record types were from DNS-OARC and Verisign.

The choice not to use libunbound as a fully recursive resolver was performance and that it’s for one simply not the job of an application to perform recursive DNS queries.

In my own case, I’m running a local instance of DNSSEC-Trigger and that is my operating systems default resolver. I’ll be able to perform the DNSSEC resolution without any issues. Ingo also indicated that the table at the bottom of the Preferences panel will fill up with domains as you start to connect to sites (any sites – DNSSEC-signed or not). You can then specify what the DNSSEC-related behavior is for individual domains.

That’s how this all works, of course, when you have both publicly accessible SIP servers with SRV records – and DNSSEC signatures on those records. There may not be a whole lot of those sites out there quite yet, but having apps like Jitsi available will only help.

If you have a SIP- or XMPP-based VoIP or IM system (or “Unified Communications” system to use the appropriate marketing buzzwords) where you can sign your domain with DNSSEC, definitely check out Jitsi and see how it works. And as you have it working, I’d certainly love to hear from you and perhaps feature some examples in future blog posts.

The Jitsi team is also very interested in feedback and indicated that sending messages to the “dev” mailing list (and joining that list if you want) would be the best way to proceed.

I’m also personally interested in trying this out in a test environment… if you’ve got a SIP server with a domain that is DNSSEC-signed, please drop me a note as I’d like to try calling you.

Kudos to the NLnet Foundation for funding this work and to Ingo Bauersachs and the Jitsi team for implementing it all. I’m looking forward to seeing where this goes!

P.S. Wikipedia has a decent page on SRV records if you want to know more about these record types.