Aastra 6739i

Known Issues

There is a serious security hole in the web interface for Aastra phones that allows anyone with access to the configuration pages to be able to see the sip credentials, including the "SIP Password", in the source code of the web pages. For this reason, we very strongly urge the following steps be taken to secure the phone:

  1. Change the administrative password for phone access, The default password is widely know, and makes access to the web interface easy. It's also a best security practice.
  2. Keep ALL phones behind a NAT device at all times. Ensure that there are no web interfaces accessible at port 80 from your network to the internet. We have reported this issue to Aastra. Presently there is no timeline for a resolution. 


Aastra now allows public download of documentation and software at:

Phone network configuration completed.

The following instructions assume your phone has successfully booted and completed network configuration including obtaining valid IP addresses for itself, an IP gateway and DNS servers either via DHCP, manual or other means (refer to your Aastra Administrator's Guide) and that your phone is running with factory defaults.

Phone is running firmware release 3.0.1 or better.

You can find the firmware version your phone is currently running by using the "Options" button on your phone and navigating to "Phone Status" -> "Firmware Info". If you are running a version prior to 3.0.1, please upgrade your phone's software before proceeding (refer to your Aastra Administrator's Guide).

Step 1: Gather information for each user.

Each user has a set of credentials which will be needed to configure each phone. For each phone that you are configuring, obtain the following:

  • "SIP Address" (Address of Record)
  • "SIP Password"
  • "Auth Username"
  • "Username"
  • "Proxy/Domain"

You can find this information in the user detail pages under the "Users" tab in the "Phone Configuration" section.

Phone configuration section

Step 2: Log into your Aastra phone through a web browser.

When your phone is powered on and connected to your LAN, use a browser to navigate to the IP address of your phone. You locate your phone's IP address by selecting Options, then scroll to phone status and finally to IP&MAC addresses. The factory default administrative username for the phone is 'admin' and the factory default password is '22222'. Go to "Operation" and select "Reset". Then reset the Factory Defaults and Remove Local Config settings. Then, select "Line 1". 

Step 3. Enter your user information from Step 1.

Basic SIP Authentication Settings Section

  • Screen Name > Whatever you would like others to see when you call them.
  • Phone Number > "Username"
  • Caller ID > Whatever caller ID you would like displayed on outbound calls.
  • Authentication Name > "Auth Username"
  • Password > "SIP Password"
  • Line Mode> Generic

Basic SIP Network Settings Section

  • Proxy Server> "Domain"
  • Outbound Proxy Server>
  • Registrar Server> "Domain"
  • Registration Period> 600

Click the "Save Settings" button.

Global SIP settings 

Step 4. Confirm that you have disabled all Network Address Translation (NAT) settings.

We handle all NAT related issues. If your phone was set to factory defaults before you began configuration, your NAT section will appear as below:

Advanced network settings

Step 5. Disable unnecessary codecs.

Navigate to RTP Settings under Global SIP Settings. Set codecs to match this screenshot. Make certain to set the Packetization interval to 20.

Codec preference list

Previous to version 2.5

Navigate to RTP Settings under Global SIP Settings and check the Basic Codecs box. This is all that is necessary for compatibility with OnSIP and sending extra codecs can cause problems with packet size.

Codec preference list

Click Reset.
Click Restart Phone. 

Step 6. Confirm that your phone is registered.

In the Admin Portal, click on the "Users" tab. You will see a green "online" notation next to each user with a registered phone. 


If you are experiencing trouble, double-check your settings as described above and be sure to verify that your password was entered correctly without any leading or trailing spaces. If you are still having problems with your phone configuration, please see our troubleshooting section for further help. 


First unveiled late last year at the BroadSoft Connections executive conference, the 6739i is Aastra’s most advanced enterprise class IP desk phone to date. It has drawn many comparisons to other premium solutions from top competing brands like the Polycom 670 and the Snom 870. We will eventually get to testing and reviewing all of them; the 6739i just happens to be the first one up. 

First Impressions

Simply put, the Aastra 6739i (firmware v3.0.1.38) is the nicest desk phone I’ve ever used. This probably has a lot to do with the 5.7” 640 X 480 display, Aastra’s first color, touch screen display. The resolution is comparable to what you get on the iPhone 3G and 3GS; much better than the 320x160 display on the Polycom 550 that I’m used to. The large screen may make the device seem bulky at first, but the 6739i actually uses the exact same frame as the models in the brand’s 5Xi series. High end enterprise class IP phones from competitors like Polycom and Grandstream are bigger and heavier.

The phone comes feature loaded with the capacity for 9 lines and 9 separate call appearances. Three lines get dedicated hard keys with their own LED indicators, and the rest can be programmed in as softkeys that show up on your touch screen. Here is just a quick list of all the main features, taken straight from one of Aastra’s data sheets:

All of this does come at a price though. Expect to shell out over $360 to get your hands on one of these. OnSIP Interoperability TestAll Testing of the Aastra 6739i was done on firmware version OnSIP, we put each of the phones we use through a multi-step interoperability test in which we put the phones through 30 test cases. An example of a test case would be the following:

Test phone calls phone B

B picks up

B puts Test phone on hold

B calls phone C

C picks up

B transfers test phone to C

Call must be transferred correctly to C. B must be released correctly after the transfer. When C picks up, audio must work in both ways between test phone and C. When test phone is on hold, there is no audio between it and phone B.

The Aastra 6739i passed each of our test cases. Voice QualityAt the 2009 ITEXPO, Aastra announced that it was providing G.722 wideband audio codec support in the form of a firmware upgrade to their 67xxi phones. Keep in mind that many of Aastra’s older phones do not have all the hardware components to support HD audio in all its glory, making these phones more HD compatible than HD capable. We’ve tested out Aastra’s ‘Hi-Q’ for ourselves on the older 6757i model. While there was a very noticeable improvement in audio quality, it still wasn’t quite as good as the ‘HD voice’ audio of our Polycom 550s/650s.Enter the 6739i, a phone with the upgraded ‘full frequency response’ hardware to give rival Polycom some good competition. The sound quality is indeed excellent, but is it better than what you get on a high end Polycom 650 phone? To be honest, I cannot really tell the difference. If I had to pick favorites, I would choose the voice quality on the 6739i handset over the 650 handset, and the 650 speakerphone over the one on the 6739i.Regardless of which phone you choose, you’re going to get amazing audio.For a more in-depth analysis of the voice quality of the 6739i, I will defer to VoIP blogger Michael Graves. In this post, he pits the two phones head to head with full audio clips and graphs that show energy vs. frequency (very cool!). While he admits that his tests are “completely unscientific and not really a rational basis for comparison”, it should still give you a good idea of how the 6739i measures up against one of the best sounding phones available. Ease of UseIf you were not happy with Aastra’s rubber buttons on previous models, then you probably will be disappointed to learn that the 6739i does indeed have rubber buttons. While I would agree that solid keys are more satisfying to use, this is not a major issue for me. Many of the buttons have been moved to the touch screen so it should not be as big a problem for people who strongly prefer solid keycaps.Some people have brought up that the phone does not tilt high enough. Users complained that they had to get right up to the screen on some Aastra models just to see anything. If you happen to have fluorescent light fixtures directly above your desk (like I do right now) then there might be times when your screen is obscured with glare. However, since the display on this phone is so above and beyond anything previously released from Aastra (not to mention that it takes up the majority of the real estate on the phone), it is very unlikely you will find yourself struggling to make out the screen.Aastra does now offer an optional High Angle Stand for their 67xxi phones. This accessory will run you about $20.

Aastra features Aastra features

XML Applications and Softkey Setup

Setting softkeys up all at once in the web interface is much easier.


Built In Bluetooth

Unfortunately I have not yet tested the bluetooth capability. I did do a little digging around on the feature and found that most of the feedback has been positive.

Built-in Bluetooth works very well, we've used a number of different headsets with it without issues. [Link]
The main reason for me getting the 6739i was for the bluetooth and some of its other features. I've been using a Jawbone icon bluetooth headset without a problem for the past few days. It's nice to be able to walk around the office and do things while talking on the phone instead of being tied to my desk. The phone automatically connects to the headset if you go out of range and come back into range, which in my office is about 15-20 feet I'd say before you lose connection. [Link]

Do take these comments with a grain of salt since you never really know who is actually a reseller.

VoIP blogger Michael Graves wrote another interesting post on the subject, where he points out that Aastra's recommended bluetooth headsets for the phone do not support wideband audio. 

Final Thoughts

Is the Aastra 6739i worth the price? That depends. To be honest, it would take a lot of convincing to get me to spend $360+ on any desk phone, regardless of how many features it has or how nice the LCD display is--but that's just me.

I will say that the phone does a lot of the convincing all by itself, but if you're not a heavy phone user, then the 6739i probably isn't for you. If, however, some of features mentioned in this review would make your work life significantly easier or you have something like a dedicated Asterisk server for some of the cooler XML applications, then maybe this phone is the perfect fit.

Aastra front view Aastra back view


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