DAHDI (previously Zaptel, also/originally Zapata Telephony technology) is/was the hardware/software/systems implementation that allows Asterisk to interface with physical telephony interfaces, provide functionality in software essential to traditional telephony (whereas previous, hardware-implemented designs did this in rather expensive hardware), and, probably most-important to the "radio" type uses of Asterisk, provides synchronization, routing, and combining (conferencing) of audio streams within the system. So, it is essentially an interface between the "physical" "telecom" world, and the "computer" world. Asterisk is the "computer world" part of the system. It provides "call-level" telecom functionality (call switching, call routing, voice interaction, application interface, logging, etc), in addition to audio-stream-level interface and functionality for computer-related voice transport (such as VOIP). Since Asterisk has good application support, it was easy to make it a REALLY good platform on which to implement radio control, since it had nearly all of the characteristics necessary to do so inherently, and was not difficult to add what it lacked. LibPRI is a protocol library for for Primary rate ISDN telecom services. It was included mainly for completeness. I seriously doubt that anyone that initially implemented a radio system has much use for this, but trust me, several people that initially implemented telephone switches using my distro and THEN decided to put a radio interface or two on it, were certainly happy I did it this way. Obviously, LibPRI is not needed for a purely "radio" environment. Zaptel (as mentioned above) was the previous name of DAHDI (don't blame me!! I didnt come up with EITHER of these names!!) Jim WB6NIL "Daddy of DAHDI" -- As I was called by Mark Spencer circa 2008 (while at an Astricon) P.S. I cant tell all of you how tempted I was to answer more like this: DAHDI - Counterpart of the "MAHMI" technology. Once together, DAHDI and MAHMI spawned a number of derivative technologies, such as "SONNI". Sadly, DAHDI and MAHMI don't functionally inter-operate well anymore, and, as you might imagine, SONNI, now requiring two distinct interfaces (one for DAHDI, one for MAHMI), sometimes has interface "issues". :-) :-) :-) From: kk6ecm@gmail.com To: App_rpt-users@ohnosec.org Date: Thu, 11 Sep 2014 19:51:41 -0700 Subject: Re: [App_rpt-users] What is Dahdi? This is what I understand... but looking for an expert view from someone else. Dahdi - Asterisk & hardware device interface Asterisk - telephony switching and PBX service Libpri - protocols used by Asterisk/Dahdi? Zaptel - interface functionally similar to, and predating Dahdi? Bob kk6ecm From: app_rpt-users-bounces@ohnosec.org [mailto:app_rpt-users-bounces@ohnosec.org] On Behalf Of George Csahanin Sent: Thursday, September 11, 2014 6:53 PM To: App_rpt-users@ohnosec.org Subject: [App_rpt-users] What is Dahdi? OK, not being a wise-ass, not trying to be stupid, that part’s covered. Just trying to understand. What are the specific functions of: Dahdi - Asterisk & hardware device interface Asterisk - telephony switching and PBX service Libpri - protocols used by Asterisk/Dahdi? Zaptel - interface functionally similar to, and predating Dahdi? I know they are all part of the whole package, and that whole package still has me in awe. But being very curious type I wanted to know how this all comes together. In my simple mind I axe: why isn’t Asterisk enough? I know what that one is, but as I use app_rpt daily I wish I knew which of the above are providing what part of the overall system. George J Csahanin W2DB Allstar 2360 Echolink-Free Cedar Park, TX 512-401-2630 home 401-338-0568 cel _______________________________________________ App_rpt-users mailing list App_rpt-users@ohnosec.org http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users To unsubscribe from this list please visit http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users and scroll down to the bottom of the page. Enter your email address and press the "Unsubscribe or edit options button" You do not need a password to unsubscribe, you can do it via email confirmation. If you have trouble unsubscribing, please send a message to the list detailing the problem.