Articles tagged with voip

  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. 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 …

  3. 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 …

  4. 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 …

  5. Stop That Linksys VMWI Half Ring

    Posted on in voice

    Linksys / Cisco SPA-2100 Ring Splash HighlightedIn my office here at the Slaptijack world headquarters, I have a cordless phone attached to a Linksys (née Sipura) SPA-2100. Thanks to the Visual Message Waiting Indicator (VMWI), I have a nice blinking LED whenever I have a voicemail waiting on my Asterisk server. Unfortunately, the Linksys SPA-2100 is …

  6. Setting the Linksys VoIP Phone Daylight Savings Time Rule

    Posted on in voice

    If you use a new Linksys VoIP phone (for example, the Linksys SPA942), you probably don't have to worry about the change to Daylight Savings Time that began in 2007. By default, your phone has the right information about when Daylight Savings Time begins and ends.

    On the other hand …

  7. Using Multiple Outbound Dial-Peers on Cisco Access Servers

    Posted on in voice

    You might run into a situation where you have multiple PRIs or T1s for outbound calling on your Cisco Access Server (Cisco AS5350 or other model). In order to ensure that all outbound calls are using both circuits, you need to configure two outbound dial peers. In order for the …

  8. Debugging AGIs In Asterisk

    Posted on in voice

    Asterisk LogoTrying to debug an <acronym title="Asterisk Gateway Interface">AGI</acronym> in Asterisk can be a frustrating experience. The main problem is that STDERR only outputs to the terminal Asterisk was started from. In most cases, this means the terminal is the server console. If your Asterisk server is sitting …

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