Your UA Your Way


At Callcentric, we embrace the BYOD (Bring Your Own Device) idea. Using the services you want on your terms and using the UA (User Agent software or hardware) you want on your terms are mantras we operate by. Because of this it is very interesting to see the various UA  that is used on the Callcentric network. From simple softphones to complex IP PBX systems, our users truly embrace the flexibility we provide, and we appreciate that. We want to share some of this information with you so that you can see what we might encounter on a daily basis.

We come across unique gems, as well as complicated, not to mentioned sometimes broken, software and hardware. However at the end of a days work we try our best to help resolve the many issues that we encounter.

We collected the data below over the course of a month at Callcentric. The results represents a sample of what can be considered a normal distribution of UA on any given day. We have provided our report in various, self explanatory, sections. Essentially this is a basic report for fun informational purposes.


What would you think was the most popular type of device/software used with Callcentric? We would have thought softphones and/or ATAs. If you thought the same thing you’d be right.

NOTE: The percentage discrepancy is due to rounding errors.



ATA (Analog Telephony Adapters) Adapters


IP PBX (Private Branch Exchange)


Mobile Softphones


Desktop Softphones


IP Phones


Cordless IP Phone


Our most popular category are ATA adapters, followed by IP PBX systems. Surprisingly mobile softphones outnumber desktop softphones. Finally, pulling up the bottom portion are IP Phones and Cordless IP Phones. You can see a visual representation below:



We can get a bit more detailed based on this information, and will investigate each category to get a better picture.



ATA (Analog Telephony Adapters)

Adapters that allow you to use your regular phone with Callcentric.

Desktop Softphones

Softphones that run on your desktop

Mobile Softphones

Softphones that run on your Android, iPhone, Blackberry or Windows phone device

IP PBX (Private Branch Exchange)

Full features phone systems such as Asterisk, Freeswitch, Voicent and others.

Cordless IP Phone

DECT based systems that allow you to replace your traditional DECT with IP capable ones

IP Phones

Your standard IP Phones that sit on your desk

We have broken down our data by category and selected the most populous UA from each category and presented them here for you.


The most popular category on our network consists of the more well known and stable devices, in addition to some new ones. The Linksys PAP2/T devices take up  35.2%, while the SPA devices take up 18.9% of our ATA base. These Linksys devices have proven to be popular and stable and that would explain why they are so ubiquitous on our network. Obihai follows with 23% and 7.2% for their Obi 1XX and 2XX series of devices. Grandstream has a wide range of devices spread across various ATA models. Only their 2XX series of devices show up at the top.


There are a few other UA which did not show up in the top but are still popular. Notably the Grandstream HT5XX devices, the AVM Fritzbox devices and the obscure, yet still functioning, Innomedia devices. Cisco’s newer devices are also slowly gaining traction.


If there’s one thing we’re sure of it’s that IP PBX users use a wide range of versions and configurations. Most notable is Asterisk with it’s many variations: FreePBX at 24.3%, Asterisk 1.2 and 1.4 at 9.6%, Asterisk 1.6 at 6.3%, Asterisk 1.8 at 4.6% and Trixbox (FONCORE) at 3.5%. We also see 3CX with a strong showing and 17.8%, 5.2% and 2.2% with their various versions. This is understandable considering the strength and capabilities. We also have many users using the Voicent PBX software with us, although not always successfully. We also have the Cisco UC (Unified Communicator) devices, which can be very difficult to configure, but does run stable once you are able to get it configured desirably.  Rounding out the top PBX solutions is the Avaya line of PBX solutions.


Although these are the top PBX solutions we do see a plethora of others such as the SPA9XXX and SPA8XXX series of devices as well as customized Asterisk and FreeSWITCH solutions.


We have seen surprising growth in the use of mobile softphones, although there is a long way to go to become the top category on our network. Most surprisingly is the number of users using CSipSimple for Android at 41.3%. This softphone is stable, fast and most importantly free.  Congratulations to Regis Montoya on his excellent offering. We also see a strong offering from users using the native Android SIP client which accounts for a surprising 17.2% of our mobile softphone users. Acrobits follows suit with 11.4% and 9.6% ratios, combining to make  a 21% showing. Bria and Zoiper follow with 5.5% and 4.1% respectively.


These UA pretty much take the lion’s share of mobile SIP solutions. Notable entries come from LinPhone and 3CXPhone. We believe there is a lot of room for growth in this category and are always looking for feature rich stable mobile SIP clients to offer to our end users.


When you started using SIP most likely you used a desktop SIP client on either Windows, Linux or OSX. The most, and surprisingly, popular desktop softphone is the NCH Expresstalk software. This UA comes in at 29.8% of our desktop softphone base and actually doesn’t create too much trouble, only enough to keep us on our toes. We see X-Lite following with 19.8% followed by the Callcentric softphone at 18.2%, which is the go to option for most users who are new to VoIP and want something easy to test with. We also have ZoIPer Communicator at 9.7% which is a stable and usable softphone solution. Eyebeam rounds out this list at 4.4%, and as a paid solution has a very strong showing here.


There are other softphones which do not show up on this short list but are pretty popular. Namely: LinPhone, Jitsi and Ekiga which are all open source softphones.


We ourselves use various IP Phones at Callcentric and are always interested in seeing what our end users use and think about IP Phones in general. Right out of the gate we see that the Cisco SPA line of devices are the most popular IP Phones with 28.3%. Grandstream follows with their excellent GXP series of devices at 16.0%. We use snom devices primarily at Callcentric and are happy to see that other users do so as well, 12.4% approximately. We have the Linksys SPA942 and Panasonic series of IP Phones round out our list with 9.2% and 6.9% respectively.



Cordless IP Phones are something we don’t see too much of, considering they make up only 2% of our user base; however we do have one company who is definitely making a big splash wit their devices: Gigaset. Gigaset has all of the top spots for Cordless IP Phones with the A580 at 47.3%, C610 at 29.5%, S685 at 11.6% and C470IP at 11.0% taking the lion’s share of this group.


We should note that there are some competitors such as the snom m9/m3 devices which are not as popular but offer similar benefits.


Now if we put all of this in perspective, is there on UA to rule them all? The answer is simply yes. The PAP2 is the most ubiquitous UA on our network. In fact the ATA category is the most popular with entries from Linksys, Grandstream, Obihai and AVM Fritzbox. IP PBX solutions are also very popular on our network, with 3CX and Asterisk taking most of our overall IP PBX population. Mobile SIP clients also make a strong showing with CSIPSimple, the native Android SIP client and Acrobits being the most popular ones.



We would like to mention a few UA which did not rank high but which we believe offer excellent value and features. We may be reviewing some of these UA soon, if we haven’t already, so stay tuned:



snom M9

A nice upgrade to the snom m3. The M9 has improved ergonomics and good performance. We see a few people using it with no problems.


Open source software that actually works. Hopefully with more exposure more users will start using it.

Grandstream GXV series

Excellent IPPhone from Grandstream. We reviewed the GXV3140 and can’t wait to test the GXV3175

LinPhone for Android and iPhone

Another  open source solution that is not the prettiest but we see some users using it with no problems.


Complicated but stable PBX. The FusionPBX interface adds a lot of value to this Asterisk alternative.

We come across a wide range of UA and scenarios and can honestly say that it has helped us become more adept at assisting our end users, whether using free or paid services. While we have come across some issues which are pretty standard we have come across some very complicated issues with some very complicated UA. This article should help to show the range of devices we work with and are comfortable with. You can rest assured that at Callcentric we most likely know your UA and, if we don’t, will try our best to get to know your UA in order to help you get the best out of your Callcentric experience.