Question

Asterisk has Asterisk Manager Interface (AMI) and Asterisk Gateway Interface (AGI), using which one can trigger PHP scripts at certain events from Asterisk. Using the same PHP scripts can also instruct Asterisk what to do next to a call/conference. Are there parallels to AMI and AGI in FreeSWITCH?

Answer 1

These are good questions. I just wanted to add a few things to what @dkwiebe said (which is correct, BTW).

The AMI equivalent in FreeSWITCH is the event socket. (Technically it’s not the “Event Socket Library” or ESL, which is an abstraction layer for writing programs that use the event socket. I just wanted to make that distinction.) In fact, the FreeSWITCH equivalent of “asterisk -r” is actually an ESL-based program called “fs_cli” – short for FreeSWITCH Command Line Interface. The fs_cli program is a great example of what you can accomplish with ESL.

Also, there is no reason that you cannot use an ESL program to do many of the things that can be done with AGI scripts. The ESL “connection object” can “lock on” to a single call leg and control it. There are examples on the wiki and the forthcoming FreeSWITCH Cookbook will have some recipes on the subject. (Full disclosure: I am a co-author of the FreeSWITCH Cookbook.)

Another ESL-related method of controlling calls like AGI is with the fs_ivrd daemon. It’s less commonly used than ESL but is a nice option for AGI-like scripting. See this wiki page for more details.

Lastly, I would like to mention that Lua is a great choice for doing scripting/logic/etc. in call control. It is simple, light, and easy to learn. In the lab we’ve seen a few thousand concurrent Lua-controlled calls on an 8-core machine. Lua works even in some very demanding environments.

Feel free to join #freeswitch on irc.freenode.net to discuss your questions with the FreeSWITCH community.