Building a Call Center with LTSP and Soft Phones

Need to equip an office with terminals and phones, all on a small budget? With LTSP and KPhone, you can do it with only terminals, sound cards and headsets.

We now have KPhone installed and able to be run from any terminal attached to the LTSP server. Adding another user is as simple as creating an account for them on the server, adding a SIP phone entry for them on the phone system and having them configure KPhone. The terminal server is the single point of maintenance for everyone's desktops. Even though KPhone runs locally on each terminal, the LTSP build environment is the single point of maintenance for all of them.

The cost for the system is concentrated in the terminal server and phone system. The incremental cost for each new user is the cost of a low-end terminal and a sound card headset. This expense is much more cost effective than putting a full workstation at each desktop along with a headset-capable hard phone.


Thanks to James McQuillan at the Linux Terminal Server Project for his excellent documentation (LTSP and LBS) and everyone on the LTSP IRC channels that helped me get KPhone running locally. Also thanks to Thorsten Kukuk for authoring “The Linux NIS(YP)/NYS/NIS+ HOWTO”. Thanks to Mark Spencer, Digium and everyone involved with the Asterisk Project who have made open-source telephony a reality, as well as the author(s) of KPhone. And thanks to Trolltech, the creators of the Qt application framework.

Resources for this article: /article/8460.

Michael earned his degrees in Computer Science from Michigan Technological University and Purdue University more years ago than he likes to admit. He now lives in rural Michigan with his wife and five children. He has been using Linux since 1994 and now works with Ideal Solution, finding new and creative ways to put open-source software, including LTSP and Asterisk, to work for clients. He can be reached at



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Voice separate from LTSP

Dr. Dave's picture

We have successfully built multiple Call Centers using LTSP, however for the voice we use Grandstream Phones with headsets. Keeping the Voice and workstation separate makes a lot of sense in an Enterprise Call Center or BPO environment. If for some reason your LTS server takes a dive, it does not effect your voice server and you can continue to at least answer incoming calls until the system is back on line. The other reason is the separate SIP box or SIP phone from Grandstream has much better quality sound then trying to combine everything into one. Linux Terminal Server Project LTSP on our web site. VICIdial is another really good product that runs on LTSP.

Good Knowledge

haber's picture

Thanks for good knowledge.

Linux Desktop Multiplier

Trevor Poapst's picture

Great article. Another consideration would be to use the Multiplied Linux Desktop Strategy to lower costs even further - With the Desktop Multiplier, you can connect up to 10 call center user stations to a regular desktop (Intel P4 2.6Ghz or better with 2GB of RAM recommended).

Licensing is only $99 per seat, which is much cheaper than the hardware, management and electricity costs associated with the LTSP thin-client hardware. Plus, you'll get better performance. Each user station is connected directly to the PC and, as such, has dedicated video access.


der-Vertrag's picture

Thats a great idea.

i bookmark it

8165.tgz missing

Anonymous's picture

i'm trying to build my how call center with your idea but there's no 8165.tgz in your ftp web site... any ideas where i can find it?

8165.tgz missing

Keith Daniels's picture

This has been repaired and you can now link to the file.


"I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone."
-- Bjarne Stroustrup

sound quality

Anonymous's picture

Great article - the amount of time we waste reconfiguring workstations for the temps - seems like a revolving door. This is a sensational alternative. .. are you saying that the sound quality is equal to that of a hard ip phone ? All experiences i have had with the softphones has left a little to be desired (even in a switched LAN environment). Sound quality is important to us.

sound quality

Anonymous's picture

this is an interesting project but with today's cheap hardware ip phones and linux audio issues not to mention network issues (voip should be on it's own prioritized vlan for example) I would go down hardware based route for call centers with ltsp and asterisk - You can abstract out the extension/agent to virtually link the logged in user on the phone and on the terminal.

I would say the above example would be particularly useful when you need an agent logged in to the phone system with software on the terminal (as well as the hw phone) to provide screen pops for inbound calls.

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