Articles in the voice category

  1. Pro Tip: Keep Asterisk Configuration Files in Version Control

    Posted on in voice

    An Asterisk server has a very involved configuration system. One instance I manage has over 100 configuration files. As these configurations grow, it can be helpful to have a separate server running for testing and debugging problems. If you are planning a major change, it's often helpful to get it …

  2. Factory Reset Broken OnePlus One

    Posted on in voice

    This is a sad story. A few weeks ago, I set my OnePlus One down on a table outside so that it would not be in my pocket while I worked on the pool. I have done enough work on the pool to know that at any moment, I might …

  3. Asterisk 1.2 Variable Length Limit

    Posted on in voice

    It seems the maximum length for variables (at least those in extensions.conf) in Asterisk 1.2 is 255 characters. Running into this problem has to be uncommon, but it can really bite you if aren't aware.

    Although I am only aware of this limitation in Asterisk 1.2, it …

  4. Cisco IP Phone: Rewrite Dialed 10 Digits to 7

    Posted on in voice

    If your carrier doesn't allow 10 digit dialing for local numbers, you are probably pretty annoyed that you can't just hit the redial button on those missed calls. It's possible to rewrite these dialed numbers in your phone system, but I wanted to do this on my Cisco 7961 IP …

  5. Adding Removing Dynamic Queue Members (Asterisk 1.4+)

    Posted on in voice

    Asterisk Logo In Asterisk 1.4 and above, you can dynamically add and remove queue members from an extension or the command-line interface (CLI). Although you will most likely do most of your adding and removing via extensions, you might also find it helpful to remove a queue member by hand on …

  6. Two Random Asterisk-Related SQL Queries

    Posted on in voice

    I hate losing useful SQL queries, so I tend to save them. Ever so often, I stumble across a file of queries from some work I was doing months ago. The following two queries are just such a case. I was analyzing some call data for a call center that …

  7. Linksys IP Phone Upgrade URL

    Posted on in voice

    Although Cisco now markets these phones and ATAs via their Small Business line, I still think of these devices as being Linksys. Although the software that Cisco provides for these devices comes with an upgrade executable, it is only for Windows operating systems. I have found that the easiest way …

  8. Unable to Connect to Remote Asterisk

    Posted on in voice

    It's not often that I have to restart a Asterisk VoIP PBX. I recently upgraded to the latest version of Asterisk 1.4. After the installation was complete, I restarted the service and everything appeared to be functioning OK. Processes were running and owned by the asterisk user. When I …

  9. Voice over IP (VoIP) Protocol Review

    Posted on in voice

    Protocol Basics


    Layer: Application Transport: <acronym title="Transmission Control Protocol">TCP</acronym> or <acronym title="User Datagram Protocol">UDP</acronym> Port(s): 5060, 5061 RFC(s): 2543, 3261

    SIP (Session Initiation Protocol)

    SIP is by far the most popular protocol used in VoIP communication today. SIP was designed as a …

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