Telos ZIP One Review - ISDN Broadband Alternatives

The Telos ZIP One is one very cool piece of hardware that just may be the answer to all our old-school ISDN woes. I wrote this piece after I approached Telos and told them of my interest in ISDN broadband alternatives.

They got back to me, sent me two units for testing and thus my review here of the Telos ZIP.

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In layman’s terms, the Telos ZIP ONE is a rack-mount piece of hardware that uses a broadband connection (Intelligent Zephyr IP Codec) to stream audio in real time from Telos ZIP-to-Telos ZIP unit.

Because there’s always variable network conditions between the two units (for example, one unit using a mobile device and the other a T1 connection for internet access), the Telos ZIP is “adaptive” (Agile Connection Technology) which means it compensates for network fluctuations on-the-fly.

Let me clear the air right now and say that this unit does not handle ISDN connections. You can’t plug a phone into it, nor dial up an ISDN box – a common misconception. The Telos ZIP ONE is only used to connect to another Telos ZIP ONE via the internet.

I will say right from the start that – as an ex-broadcaster – I’m a big fan of Telos, their company and product. Indeed, they single-handedly changed the way the telephone signal was handled in radio broadcasting and in doing so, Telos made changes to the broadcast industry of monumental proportions.

I own a 1994 Telos One Digital Telephone Hybrid that still to this day works perfectly and is probably one of the most important pieces of gear in my studio. I know for a fact that when audio engineers hear that burst of white noise down the line when the Telos kicks in, they know I’m running a pro studio.

That said, it was with great pleasure and humility that the good folks at Telos agreed to send me two Z/IP ONE units for testing and review upon my request a long time ago….regrettably it has taken a long time for me to compose this article for a number of reasons.


When I first got wind of these units, my first thought was that if there was anything that was going to get the attention of audio engineers with respect to an ISDN broadband alternative, it was likely going to be a piece of hardware, not software.

Face it, software can be full of bugs and unreliable, whereas hardware tends to either work great….or not.

Plus, there are literally thousands upon thousands of Telos Zephyr ISDN units all over the world. To an audio engineer, replacing one Telos unit with another would make perfect sense upon the ultimate demise of ISDN. In this way, I feel that Telos is a front-runner in the race to replace ISDN with broadband technology.

The Eagle Has Landed

I had to wait a while for some “B-Stock” Z/IP units to come in; understandably, Telos wanted to send me something that was already opened. This took a while, as very few of these units malfunction or otherwise get returned to Telos – a testament to their rock-solid reputation for delivering a quality product.

When the packages arrived, I had already thought through how I was going to test them out. Clark Novak – Marketing Manager at Telos – said in an e-mail….

“Hey, you didn’t say this was going to be a torture test! ;)”

Torture test indeed. 3 locations in total – thousands of miles in-between – bridging my ISDN through two ISP’s, one of them via a smart phone. More on the test later.

The manual

At the risk of seeming a touch odd, I’ve always loved the way Telos composes their manuals. They’re very well thought out and always with a tip of the hat to those who struggle technically – like your average radio announcer. Radio announcers know what button to push, but not a clue how any of it actually works.

Detailed and in-depth beyond belief, I read the thing front-to-back, learning all kinds of stuff along the way including a subject that I hadn’t taken the time to delve into personally – audio codecs.

The manual reveals a great deal of information about the audio codecs supported in the Telos ZIP – and there’s a ton of them. Granted, this unit is designed primarily for broadcasters who collectively require a myriad of codec options with which to stream an audio signal….AM, FM, Station-to-Station, streaming a rock concert in real time, etc.

There’s also detailed sections on how networks function, mobile network devices and then all the important stuff about the Telos ZIP itself.

Digging deeper….

I’m going to be careful to keep things general here and not get too technical. I’ll tell you why. This is a highly sophisticated unit….technically speaking. It’s intuitive, yes…and fairly easy to get up and going with it’s Quick Setup and default settings. However, should one choose to delve deeper into the minutia of the Z/IP’s configuration settings and functionality, it can be a touch daunting.

It provides four main network functions; WAN, LAN and WiFi and is also a router. You can connect your cell phone to this thing wirelessly and use it’s Internet access to stream audio….which is what I did on my first test. You can also connect it to a LAN or WAN and use it as a router.

The Z/IP provides a total of 12 different audio streaming options (codecs), each with their own bitrate and buffering settings. I like the option of 24 bit PCM Stereo at 1152 kbps myself….but that’s pushing the limits of my internet connection….LOL!

You get the picture – the sky’s the limit with respect to streaming options.

Then, there’s the directory. While the Z/IP connects directly to another Z/IP to stream audio in real time, it also makes a connection to a ZIP Server for access to Groups and Directory services; lists upon lists of other “visible” Z/IP units in the field; each unit with it’s own unique address on the internet identified by it’s Group and Unit name.

If the directory is any indication of the popularity of this product, one cannot help but wonder how long ISDN is going to survive. I’m going to venture to guess that there’s thousands of units out there already.

I particularily like the Web Interface; you can access the Z/IP’s configuration settings using the browser of your choice. This makes setting up the Z/IP a heck of a lot easier and also gives the user a better understanding of the unit in general via it’s well thought out GUI.

Then, there’s Livewire. Don’t get me started.

There are four XLR input and ouput jacks on the back of the unit to hook up your analog gear, a parallel port for backward compatibility with the Telos Zephyr Xstream and other functions like remote triggering, calling, etc.

Oh…there’s a headphone jack and a volume control…..guess I should mention that…. ;-)!

The Torture Test

As mentioned, I had a test in mind long before the units arrived. I’ve personally wanted to bridge my ISDN service in the city with my studio out at the lake. So many times, I’ve had to drive the 2.5 hours back to the city for an ISDN session, which normally meant an overnight in the city, what with the 5 hour round trip.

My internet access at the lake is my Samsung Smartphone (SGH-T989D), which creates a Wi-Fi hotspot picked up by an Asus portable router which dumps the WAN access into a Cisco 4-port switch. This way, I can share files on the LAN while all the machines have internet access.

The access is pretty good; I get about 4 megs up and 14 megs down with the smart phone’s 3G connection via my provider, Telus. There are no other wireless signals in the area to interfere with my torture test.

The trickiest part for me was signal routing back at the studio in the city, which I won’t bother to go into detail here…..but suffice to say I had to cobble something together getting creative with cables, adapters and aux sends to avoid any ISDN slap-back issues.

I got the two Z/IP’s talking to each other no problem; each showing send/receive on either end (I could access my desktop remotely).

Once connected, I streamed 16-bit PCM Stereo at 768kbps up and down. I couldn’t resist the higher codec! It was scratchy here and there, understandable given the parameters. What did come through clean was crystal-clear.

While the thought did cross my mind to use MPEG Layer II, I went with AAC at 160 kbps. My reasoning was that audio engineers in general are pretty tired with the MPEG Layer II sound after all those years having little choice with ISDN.

There was the tiniest of delays, almost imperceptible. I e-mailed my buddy to hook up to my ISDN in the city…..

Flawless. Here I was, enjoying the view at the lake (Picton, Ontario, Canada), while chatting with my pal in Washington, DC, bridging my ISDN connection……with two Z/IP units…..and my cell phone! Here’s the signal chain:

Picton, Ontario>Rode NT1000>dbx 286a>Mackie 1202 VLZ>Telos Z/IP>Cisco switch>Asus Router>Samsung Smartphone>(Telus ISP)>Rogers Cable ISP, Toronto>Engenius ESR 9850 router>Telos Z/IP>Mackie 1202 VLZ3>Delta 44 Soundcard>AudioTX ISDN>Washington, DC ISDN box (Telos Zephyr).

Just look at all that gear and technology to facilitate this test….and nothing went wrong.


There’s no question in my mind that this unit is a strong forerunner in the race to replace ISDN with a broadband solution. It’s stable, fast, clear and clean. It has all the features pro audio engineers want and need, while also keeping it simple enough for the home-studio user to operate.

Consider there’s already thousands of these things in the field, working hard every day in the realm of broadcasting; Telos’s primary clientele. It’s a no-brainer to say that the technology already has a proven track record.

So…why hasn’t everyone jumped on board?

Well, the $2300.00 price tag represents a major investment. I personally would purchase it in a heartbeat if I knew other audio engineers were all making the move. And fundamentally, that’s what needs to happen.

While $2300.00 may seem like a lot, an ISDN box can run around $5K, so the Z/IP rocks with respect to price point. And, the only additional costs are your Internet connection… more expensive ISDN lines.

Here’s the thing. Who’s going to make the first move? Pro studios and audio engineers need to invest in the technology and then basically demand that VO talent buy it as well. Much in the same way ISDN-only based studios flip the bird at voice talent who don’t have ISDN.

This is the problem; profound ignorance and general nose-picking regarding the subject.

All these old-school ISDN people are more than happy to give Telcos (telephone companies) monthly payments for ISDN because they still need to justify the $5K they spent on the box. Perhaps they should do the math and tally up their ISDN bills for the last twenty years…..

All this, while standing like a deer in headlights in front of the freight train that is the ultimate demise of the ISDN service by Telcos (telephone companies) in the very near future.

Personally, I think it’s just a matter of someone like Kirk Harnack on behalf of of Telos – the grand-pappy of the Telos-Zephyr – taking the podium at the next NAB conference and drive an ice-pick into everyone’s foreheads that ISDN is old, outdated, on it’s death bed and people better come to the realization that they need to go broadband….

Z/IP-pity quick.

“Kirk! I throw down the gauntlet! Good god man…..DO something!”

That’s all I got.

Telos ZIP One unit
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