Linux as a Telephony Platform
An interesting feature of the DBS is the ability to turn a large display telephone into a simple kind of terminal device. This allows the display content to be controlled by the application, and the application to receive input events when keys are pressed on the telephone. Another feature is a special “hot key” (also known as the ACD key), that functions as an “attention” key that generates an API event when pressed, regardless of the current telephone state.
One of the first DBS applications I created is a simple menu program for attaching “applets” to a telephone. When the attention key is pressed, a simple menu of applications appears from which one can be selected. One such application is used to immediately show status information for my server (how many users on-line, uptime, etc.) along with a soft key menu item to force a server reboot.
Another digital telephone application of mine is a more advanced speed dialer that has no capacity limit and is programmable from the telephone. This application resembles the Fujitsu “Dial-by-Name” server application in concept. The DBS has its own internal speed dialing directory. Since alphanumeric text is hard to enter through the phone, I wrote a simple Visual Basic program to connect to the SMDR programming protocol in order to program DBS speed dialing.
A possible future application that comes to mind is empowering users to program their own phones from the desktop or perhaps from web pages.
Many opportunities exist for the use of free and open systems in computer telephony, especially for those telephone vendors wise enough to expand their marketing opportunities by allowing third parties to freely address issues and applications beyond their own immediate scope. While I choose to use the Panasonic DBS and, with it, have accepted restrictions on disclosure and source publication, several other vendors have expressed interest in having their equipment featured in a follow-up article.
When I started this article, I became aware of the effort to create a standard and open Internet protocol for telephony integration, known as “stp”, Simple Telephony Protocol. After some debate, I have chosen to fully embrace stp, and the current software described in this article is being rewritten to support and comply with the evolving stp standard. The name “SwitchLink” has also been adopted for it (swilink for short). My intention is that swilink will become widely available as a free and open software package for release with all mainstream Linux distributions. Thus, free and open telephony will become the norm rather than the exception for Linux.
Recently, there has been considerable change in the attitudes of several key hardware vendors in the telephony business with regard to Linux. I now believe opportunities to write on the use of Linux as a general purpose and high performance Internet telephony platform may be possible much earlier than I anticipated.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide