Is a Skype-SIP Peace At Hand?

The race is on to bring some semblance of peace in the SIP v. Skype melee.

No, Niklas Zenstromm and Janus Friis haven’t dumped their proprietary protocol in favor of the open source SIP. And, no, the protocol hasn’t been hacked.

Instead, enterprising telegeeks have been hard at work getting Skype and SIP to simply “talk” to one another, and the fruits of their labor are starting to show up in the marketplace.

Already there are three products available that offer Skype-to-SIP connectivity, and two more on the immediate horizon.

“Why does this matter?” you might ask. There’s a simple answer, and a more complex one.

The simple one is that if Skype and SIP can truly work together, users of each can contact each other using only internet bandwidth, avoiding the tolls, and degraded communication quality, extracted by the PSTN.

The more complex answer is that interconnectivity can marry Skype’s market share (it’s huge in Europe, though reports are that its popularity has waned somewhat) and SIP’s plethora of devices (Let’s be real: Skype-only devices are basically brain-dead).

Forget the silly debate over which technology is better. There’s no answer because as with any such debate (think Windows/OSX/Linux, GSM/CDMP, plasma/LCD) everyone is partially right.

Yes, Skype is easier to install, looks flashy and feels as hip as a Prius. And, yes, SIP is more powerful, allows you to keep your computer off, doesn’t eat up your bandwidth while you’re not on the phone, and feels as hip as Ubuntu.

Either side can win the battle of words, but users are losing a big advantage of VoIP if the two sides can’t get along well.

It’s pretty clear that the technology clash isn’t going away soon, the way VHS squashed Betamax a couple of generations ago. Some time in the future, one may win out over the other or, much more likely, a whole new approach will replace both.

As it stands, the only real solution today is to make Skype and SIP like one another a bit more.

At least they’re shaking hands now, which is a good first step. With a bit of work (and a couple of bucks) it is possible to make a virtually seamless Skype-to-SIP connection. But beware: interconnection is a bit kludgy, requires the Skype client (or multiple clients) installed somewhere and works best when paired with a PBX, like Asterisk.

If you’re ready to take a plunge into the pool if IP telephony harmony, here are a few solutions:

VoSky Exchange

In the VoIP world, the folks at ActionTech are best known for the low-cost “Internet Phone Wizard,” which allows the use of a regular analog phone with any PC-based software phone (such as Counterpath’s Eyebeam and Skype).

ActionTech was first to market with a “Skype box” that allows connectivity to a regular PBX for up to four Skype accounts. And as the first to market, they are charging a premium for VoSky Exchange. At US$999, it isn’t likely to find a place in many homes.

And the bundle of cables required (4 USB cables attached to a dedicated computer running Skype and 4 RJ-11s connected to the PBX, requiring pricey add-on cards on the PBX side) makes it the type of contraption only a deep-pocketed Rube Goldberg could love.


This Skype to PBX gateway developed in Italy is pitched primarily as a way for companies to use the SkypeOut termination service to save on phone bills. If this is all that it did, however, it makes little sense in that a good SIP-based termination provider can accomplish much the same thing, often at even bigger savings.

Fortunately, the package (which starts at a whopping US$760) has quite a bit more going for it, including the ability to store Skype accounts in a “speed list” for outgoing calls, and the ability to accept incoming Skype calls using an add-on USB adaptor. The company also sells a Skype2PBX SMB bundle (US$1,750) that includes a low-end computer, USB adaptor and up to 10 concurrent Skype calls.

If the price doesn’t scare you off, this may: Unless you’re fluent in Italian, don’t look at Skype2PBX as an easy solution as the English instructions might as well be in Italian. Currently, that’s perhaps not a huge deal though. The company is not yet selling the product internationally.


From Australia comes a Windows-only software “Skype-to-SIP adapter” that, appears to be getting a bit of traction. Though Uplink designed the software primarily for use with its Windows-based PBX product called Axon (, it has been made to work with Asterisk.

At US$38.50 for a “professional license” (a free version is also available on the site), it’s not a bad solution for someone looking to connect a single Skype account to a PBX. Unfortunately, though it works relatively well for incoming calls, on the outgoing side the software is designed primarily for use with Skype’s “Skype-Out” termination service. In other words, don’t expect to be able to easily call your Skype pal in Oslo using your Linksys phone regisered to your Asterisk box.

For personal use, Uplink is a nice addition to a small scale PBX. As a business solution, however, it’s a bit lacking. If you want to provide a single Skype contact to your customers, only one can be on the phone with you at any given time. And the company has yet to work out DTMF limitations that allows a SIP call to be made from a Skype client (though a solution is expected in a future release).


Get your Linux cheat-sheets out. This new offering comes from a team of Brazilian Asteriskistas and is made specifically for their brethren the world over. If that doesn’t make you want to click the page, ChanSkype may be a decent solution.

The software comes in two flavors: A US$19 “personal license” allows a single Skype account to connect to the Asterisk server (the developers warn that it’s “a waste of money” to install more than one personal key in Asterisk “as only the first personal key will be accounted.” A commercial license costs US$99 and allows up to 30 Skype channels on a single Asterisk box.

One advantage to the ChanSkype approach is that it only needs a single computer. The same box that runs Asterisk runs the Linux-based Skype client.

This does reduce hardware costs, of course, but for some is a bit or a show-stopper. The Skype client requires that a Linux GUI interface (such as Gnome or KDE) and the X-system interface be installed on the Linux box, which most asterisk advocates strongly advice against.

Pika Connect for Skype

This product, from Ottawa-based Pika Technologies, a well-regarded manufacturer of TDM cards for PBXes (including Asterisk) looks to be very promising. Unfortunately, we can’t look at it yet as it’s not even in beta (that’s promised for early November).

What we do know comes from company announcements, and it seems like a product worth waiting for.

Pika’s solution (unlike ChanSkype’s) requires a separate computer (initially Windows only) running Skype (or multiple Skype clients) which connect to the PBX via ethernet. On the Asterisk side, a single “conf” file manages the interaction.

If your principal Skype “line” is in use when a call comes in, the software automatically rolls the call to one of your unused Skype accounts, and then back to the PBX. The number of accounts you can roll over to is unlimited, though the company expects to be licensing for each channel (at about US$45 per).

Pika Technologies is seriously looking at an embedded approach, a separate box that holds all the Skype accounts and can either act as a PBX itself, or connect (again, via ethernet) to a separate PBX for companies needing a beefier solution.

Initially, the software will be for Asterisk installations only, though other PBXes will follow.

What does all this mean? The day is not far off when you will be able to use any IP phone (or even your cell phone) to make a Skype call out, to receive a Skype call on any telephone you wish to forward it to, and to receive multiple Skype calls at the same time in a business setting.

Peace is indeed coming to internet communications.


  1. rizsher says:

    I keep hearing Skype used bandwidth when idle, some have even gone on to say it becomes part of a P2P network etc etc… in actual fact, I’ve never seen my Skype client to use more than 0.5 MB over the course of a day when I’ve not made/received any skype calls…. that I’m sure is comparable to the data a SIP device would transfer over the course of a day.

    Uplink: I tried it for a while…. doesn’t work all that well….well…actually, may work perfectly if it gels with your computer, in my case, and many others as a search on the internet revealed, it leads to random and frequent reboots of the machine running Skype+Uplink.

    You failed to mention PsgW from – RS Development Group, it costs a bit of money, but I’ve found it to work very reliably and consistently for over 2 months now.