July 2011

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There was an announcement a while ago on the xmpp.org site about Google’s adoption of the official Jingle standard. The same announcement was posted by Peter Thatcher a Google engineer to the Jingle mailing list. The announcement got a bit of attention and I originally came across it on Hacker News. After spending a fair bit of time looking into what the upgrade means as far as integrating with Google’s XMPP service the conclusion I’ve come to is not much at least not yet.

The original reason I, a SIP person, started messing around with XMPP and Jingle was to see if there was a better way to integrate with Google Voice. I made a few blog posts at the time and ultimately the investigation didn’t end up yielding any fruit because of a peculiarity in the way the Google XMPP server deals with the RTP media streams which would preclude it working with standard SIP devices (very briefly it requires that STUN packets are exchanged on the RTP sockets before the RTP can flow).

So fast forward 8 months and I finally found some time to delve into the Google XMPP service again to see if there’s any chance of getting SIP interop, or more correctly RTP interop for SIP devices, working. The other thing that spurred me on a bit was Google + and specifically the integration of the Google Talk Gadget into the Google + application. The Google Talk Gadget is not new it’s been in Gmail for quite a while but the integration looks a lot more interesting with Google +, specifically being able to call from a SIP phone into a Google + Hangout (a web based voice/video conference call) would be cool.

As alluded to above the results of my latest little adventure into Google XMPP land haven’t been very fruitful. Yes Google now appear to be sort of using Jingle for their call set up but the media side of things doesn’t appear to have changed at all and in fact the original email from Peter Thatcher did state the work on XEP-0176: Jingle ICE-UDP Transport Method, which is more down to the nuts and bolts of the RTP side of things, is ongoing. In the meantime the XMPP call set up mechanisms used by Google are a combination of Jingle and Gingle (Google’s original implementation of a Jingle like protocol) and crucially the media layer is still Gingle.

My hope is that when Google get the Jingle ICE-UDP transport implemented they will also implement the XEP-0177: Jingle Raw UDP Transport Method which should allow RTP level interop with SIP devices which will in turn allow SIP Proxy services like SIP Sorcery to make and receive calls with Google’s XMPP network. Some SIP servers that proxy media such as Asterisk and FreeSWITCH are already integrating with Google’s XMPP network by implementing the Gingle/XEP-0176 STUN connectivity check mechanisms on the RTP sockets. In SIP Sorcery’s case and also for other non-media proxying servers such as Kamailio the integration is not possible because it then needs the end SIP devices to do the STUN connectivity checks and until ICE support becomes widespread they wont be able to.

Unfortunately this is another example of the really painful issues caused by NAT. If NAT had never been invented and the World had been forced to upgrade to IPv6 the internet would be a much better place :). In the meantime communications protocols like SIP and XMPP end up with as many addendums and extensions to deal with NAT as they do to deal with their core functions!

I’ve had a couple of requests from people who made a previous donation to the SIP Sorcery project regarding whether the donation would count towards a payment for a Premium account. The answer is that yes it can. I’m happy to apply a pro-rata basis for all donations towards a Premium account. In fact all types of previous payments including donations and the eBay auctions are treated the same. If you would like to take advantage of this offer please send an email to admin@sipsorcery.com with your sipsorcery username and if your PayPal payment came from a different email address please include it or a copy of the payment receipt.

I’ve just added a new dial plan option to the SIP Sorcery Silverlight client. The dial plan option is another non-script wizard type and in this case the idea has been to make it as simple as absolutely possible, hence the name.

The Simple Wizard dial plan allows a set of rules to be specified to be applied to outgoing calls, incoming call rules will follow in the future. The creation of the rules should be straight forward for anyone familiar with SIP Sorcery dial strings. In the simplest case a dial string can just be the name of a provider. There is some help information for the Simple Wizard at Simple Wizard Help.

Simple Dial Plan Wizard Screenshot

Someone suggested this week that an IRC channel may be useful for some more technically minded people looking for help on their dialplans or anything else to do with SIP Sorcery. I’ve always been a fan of IRC so I’ve gone ahead and created a channel on freenode.net, the channel name is #sipsorcery. I’ll hang around in their when I’m working on the SIP Sorcery code which is normally 0900 to 1300 UTC (early in the morning US time, late in the evening Australian time). If anyone wants to pop in and ask a question I’ll be more than happy to help out.

In recognition of the valuable feedback and in some cases assistance to other users that Beta users have provided I have created a special offer for anyone that wants to convert to a Premium account. For a $50 once off payment (no subscription required) Beta users can purchase 2 years of a SIP Sorcery Premium service. This compares to the normal price of $35/year and represents nearly 30% off.

The Premium service has unlimited SIP Providers, SIP Dial Plans and access to all Dial Plan functions. From the 1st of Aug 2011 Beta accounts will be treated the same as Free accounts and subject to a single SIP Provider, a single SIP Dial Plan and not able to access some Dial Plan functions.

Please note the offer will only last until the 31st July 2011. After that date any Premium account upgrades will be at the normal price.

The link to the offer is below. Note you’ll be prompted to login and the offer will only show up for Beta users:

Beta Users Special Offer