SLA for DAHDI FXO – Emulating Key System Functionality

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I currently have a customer that *requires* key-system functionality in an Asterisk PBX. On a SIP phone, the BLF keys need to show the current state of the analog lines attached to the system (DAHDI FXO). By pressing one of these keys (for line 1 for example), the dialed number needs to be dialed out the correct port. Also, when that line is busy, the phone BLF key for that line needs to reflect the status.

I’ve been reading about SLATrunk but it doesn’t seem quite what I’m looking for. Also, I’m looking at using Hints to supply such information, but I’m not sure exactly how it should look.

Has anyone done this before, and if so, how did you implement it? My target is to use Asterisk 1.8 but another version would suffice.

Looking forward to your comments!

3 thoughts on - SLA for DAHDI FXO – Emulating Key System Functionality

  • I’m also very interested in working examples, especially if someone has
    set it up for SIP termination “trunks” rather than Dahdi.



  • Because we sell a product that limits the number of simultaneous calls
    on that trunk, and many of our customers have asked for key system-like
    functionality (since that is what they are used to), and to provide an
    interface that “looks” like individual POTS lines would be more
    comfortable for them.



  • Hi

    For this scenario you can use the group and group_count functions and create
    a hint dialplan like this:

    exten => trunkname,hint,custom:trunkname

    When you reach the maximum number of available channels set the hint in use:


    To remove:


    After this, configure BLF on the phone top subscribe trunknumber “extension”


    – Bakko