Aswath lit me up for saying IAX doesn’t suffer from the problems SIP does when traversing NATs. He basically wrote that I mischaracterized IAX by saying it’s immune to NAT problems. Well, I have respect for Aswath, as I’ve read his blog for years now, and the guy knows his stuff. So when he says I’m innacurate it makes me perk up.
Anyway, the point I was trying to make is, more precisely, that port-forwarding in particular doesn’t break IAX connections the way it breaks SIP connections. Aswath writes:
If so, then SIP could also decide to use a standard UDP port for media and realize the same benefit. Consider the case of an end-point that is behind a NAT.
Not true, Aswath. For one, it is NOT possible with SIP to use the same port for media and signaling, since SIP uses RTP (while IAX has its own buil-in payload protocol). For two, even if you could get all endpoints to use the same socket address for all signalling connections and media connections, SIP still doesn’t advertisig the correct socket address within its headers in a NAT scenario. More specifically: SIP headers, created by VoIP endpoints like phones and servers, include the local (not NATted) socket addresses that the responding endpoints will use to create a UDP connection back to an advertised socket at the calling host prior to the beginning of a call. So, even when attempting to port-forward SIP’s port (5060/5061), or RTP’s payload ports, the protocol simply breaks. Not because there are multiple ports, but because the protocol itself requires the use of non-NATted socket addresses in its headers in order to advertise communication pathways.
IAX simply doesn’t have this problem because the protocol doesn’t carry socket addresses to create connections back to the calling endpoint using a different socket. Rao does clarify his position by stating that the ICE traversal framework is his basis for his statement that I’m not giving the full story about IAX (because I didn’t mention direct call paths as a feature of IAX2, something just about nobody needs). But, on the streets, and especially on the SMB prem, nobody’s relying on ICE or worried about adherance, and everybody’s using inward NAT, port-forwarding, and socket translation. Seriously, ICE may be elegent but isn’t required to make IAX work in both directions through a NAT device. IAX simply works better than SIP when NAT techniques are used. Indeed, SIP doesn’t work at all with NAT (in either direction) unless application proxies are in place (STUN, a SIP media gateway, or something of the ilk).
Now, on Aswath’s point about direct call paths with IAX and SIP (which you can read about in my book Switching to VoIP), let’s face it. The only people using IAX are Asterisk users. Period. You won’t find Asterisk support on a Cisco or Avaya device. The bulk of Asterisk installations are campus-area in nature and fewer than 500 users per server. There’s literally no need to use direct call paths in the vast majority of these installs because IAX imposes little overhead on a modern server, even with dozens of simultaneous calls. In most environments where an Asterisk server would have a high enough call load to require the use of direct call paths a la CPO, you’re talking call center, you’re talking call recording, barging, conferencing, etc. The needs of a large environment necessitate centralized (ie server-proxied) call paths, making Asterisk users that much LESS likely to touch direct call paths.
So if the only people running IAX are Asterisk people, and Asterisk servers almost never experience a bottleneck requiring the use of direct call paths, seriously, who cares about ICE?
Anyway, Aswath, I love your blog, keep it coming. You should post more often! Just remember there’s more to life than protocol purity and adherance. There’s also what the street demands: practicality.
SAN FRANCISCO, Calif. — August 7, 2008 – TokBox, a first-of-its-kind web-based video communication service that offers consumers free and effortless video calling, today announced the closing of a $10 million Series B financing round led by Bain Capital Ventures. Sequoia Capital, which led the Series A investment in TokBox, also invested in the new round. TokBox will use the new funding to build out its executive team and drive continued expansion of the company’s user base both in the U.S. and worldwide.
In recent months, TokBox has added new features and functionality to enhance the consumer experience, including integrating its video capabilities into Facebook chat and providing an easy-to-use downloadable version of the application. The company also recently announced the appointment of Nick Triantos, technology veteran and video expert, as CEO.
“Consumers are in love with TokBox, and use it to keep in touch with friends and family around the globe,” said Triantos. “We’re proud of the service we’ve created and how easy it is for anyone to use TokBox. We are grateful that a world-class venture firm like Bain Capital Ventures also sees our potential, and are thrilled to have them join Sequoia Capital as investors in TokBox.”
Since launching in October 2007, TokBox has grown rapidly and is already being used in a variety of interesting ways — from people staying in touch with distant relatives and friends chatting during school holidays to online dating and job search. In addition, TokBox gives users the tools to add a video communication element to their blog, social networking or commerce and community sites profile by embedding the unique application directly into the page.
“TokBox has an impressive and very loyal and energetic user base,” said Scott Friend, Venture Partner at Bain Capital Ventures. “The company is executing well and its service offers consumers a variety of great features that strongly differentiate TokBox from competitors. We are excited to be investing with our partners at Seqouia in a company we believe has the potential to be the next ‘big thing’ in web communication.”
“Tokbox is uniquely positioned as a leader in the burgeoning consumer video communications market,” said Roelof Botha of Sequoia Capital. “Their ultra-simple user interface sets a new bar for ease-of-use for consumers to hold video calls with their friends and family around the world. We’re very happy with their growth to date, which is why we are enthusiastic to participate in their Series B investment.”
For more information about TokBox, please visit www.tokbox.com.
I was reading Esme Vos’ post lamenting the recent decline in service on domestic airlines, even as United is touting WiFi on all flights starting soon. Well, that’s a good move. While I spend my offline flying time catching up on (usually sales oriented) e-mails to contacts I haven’t touched in a while, it seems the airlines have begun charging for the use of their pathetically small and not-so-firm pillows.
Not Continental. Their crappy pillows are still free.
Tags: air travel, business, wifi
Regarding the Digium/Switchvox AA60 appliance, it’s obviously Linux and Asterisk based, but all the delightful fun ordinarily associated with Asterisk administration has been boiled down to a cute web interface that really works, and really works better than the competition.
And it’s built to run. I mean, the thing doesn’t even have a power switch. Plug it in and it boots up. Want to shut it down? Unplug it (or do a soft shutdown). Point is, there’s nothing to bump to accidentally turn off your PBX, and that’s not necessarily a bad thing. (Neither is the external power brick–much more serviceable than an internal PC power supply.)
Out of the box, the self-signed certificate on the web interface will make IE and Firefox both moan, but add it to your exception list and you’re off and running.
The version I’m looking at is SMB 3.5. The web interface is the familiar Switchvox red-bar-across-the-top with pop out menus.
Above, you can see Switchvox’s clean, snappy UI, probably one of the main reasons for the appeal to Digium, whose Asterisk Appliance had a comparatively clunky, slow UI.
The User Tool is a web-based app that any user of the PBX can log into using a browser. It gives access to personal call histories and allows the user to export his/her own CDR directly to an Excel file. Useful stuff. I can see this coming in handy for inside salespeople.
The Switchboard, launchable from the User Tool, is another web based app. It provides front-desk-like command and control of all lines, extensions, and calls within a user’s credentialed reach so they can drag and drop to perform telephony functions like call parking and so on. I’ll go into more detail on this later after I’ve provisioned a few phones on this AA60.
This Switchboard app is not as sparkly as the Trixbox HUD (which is not web-based), but I would think this would be sufficient for a small call center operator or a group manager. The only drawback is being forced to leave a browser window open. We all know how tricky it can sometimes be to surf the web with a window we WANT to keep parked a certain URL open in the background. Sometimes the browser or a client side script will decide to jack that window and poof, there goes our Switchboard. But that’s no fault of the AA60, of course.
Next I’m going to add some phones to the system. Stay tuned.
I was watching a Tribe game and saw an ad for something called LastMinuteGolfer.com. Since I was planning a trip to south Florida, where greens fees don’t often dip below $100 per golfer per outing, I was looking for a deal. LastMinuteGolfer lived up to the hype. I was able to play golf at Raptor Bay Golf Club at Coconut Point in Bonita Springs (a championship club by the standards of many) with my girlfriend for under $50 out the door. I even got a decent embroidered polo from the pro shop on the way out.
LastMinuteGolfer.com is more than just a discount aggregator, like Priceline. It’s a social community with golf-specific user profiles that allow for professional networking and shop talk that we who golf frequently associate with the sport. Good stuff. Hopefully they’re making money and will be around when I plan my next trip.
From Ifbyphone’s press release:
CHICAGO–July 29, 2008—Ifbyphone, the telephone application platform company, today announced the beta release of Ifbyphone Lead Distributor, a Web-based tool that allows users of the Ifbyphone voice-based telephone application platform to establish a virtual call center without any start-up expense.
The Ifbyphone Lead Distributor offers a host of productivity benefits for small- and medium-sized businesses already taking advantage of Ifbyphone’s ability to integrate Web and telephone services. The intelligent tool also enables businesses to distribute calls across traditional call centers to the appropriate call taker, regardless of location. Upon receipt of a call, the Lead Distributor evaluates the time of day, day of week, caller-ID and number of calls previously transferred to a particular location before determining where to send the call.
Lead Distributor works in conjunction with Ifbyphone local and toll free numbers, Virtual Receptionist, Survo Voice Forms, voice mail and call processing APIs to provide any size business with a completely hosted computer-integrated telephony (CIT) solution.
“In today’s world of virtual home-based employees, Ifbyphone’s Lead Distributor is the perfect solution for flexibly distributing calls to any phone, anywhere, including home offices, in a highly cost-effective manner,” said Ifbyphone CEO Irv Shapiro. “By integrating interactive voice dialogs with automated call distribution we are able to deliver the power of enterprise call handling to businesses of any size.”
All Ifbyphone services are configured from an easy-to-use Web site. Once configured, the services are immediately available. Call recipients use their existing telephones and require no specialized equipment or software.
Ifbyphone Lead Distributor is available directly at www.ifbyphone.com or through a network of value-added resellers for an affordable monthly fee, with no upfront costs.
