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Lua example Bridging two calls with retry

About​

The following code makes one call first, retries max_retries1 times, alternating between 2 different gateways, once the call has been established, it plays a greeting message, it makes the second call, retries max_retries2 times and once the second call has been established, it bridges the two calls. There are also two lines of code included for enabling call recording in stereo (one leg per channel).

Notes​

  • The uuid parameter is used so you may identify the call through the Event Socket by reading that call/channel variable.
  • The dialstrXY parameters should be in the form: sofia/gateway/gateway_name/dial_number or similar, following the originate command specifications and according to what kind of call you would like to make
  • The greeting_snd parameter is optional, if it is not passed, the greeting message won't be played after the first call is established
  • Depending on the format of your greeting_snd file, you might need to install and enable mod_shout
  • You have to save this code in a file, e.g. bridge.lua, and then run it by issuing 'luarun bridge.lua uuid dialstr1 dialstr2 dialstr12 dialstr22 [greeting_snd]" (greeting_snd is optional). You can do this either from the console or through the Event Socket

Script example​

uuid = argv[1];
dialstr1 = argv[2];
dialstr2 = argv[3];
dialstr12 = argv[4];
dialstr22 = argv[5];
greeting_snd = "";
if (#argv > 6 and not argv[6] == "") then
    greeting_snd = "/tmp/audio/"..argv[6];
end
max_retriesl1 = 5;
max_retriesl2 = 3;
connected = false;
timeout = 45;
freeswitch.consoleLog("notice", "*********** STARTING Call ***********\n");
freeswitch.consoleLog("notice", "*********** DIALING "..dialstr1.." ***********\n");
originate_base1 = "{ignore_early_media=true,originate_timeout=90,hangup_after_bridge=true,uuid="..uuid..",leg=1}";
originate_str1 = originate_base1..dialstr1;
originate_str12 = originate_base1..dialstr12;
session1 = null;
retries = 0;
ostr = "";
repeat  
    retries = retries + 1;
    if (retries % 2) then 
        ostr = originate_str1;
    else 
        ostr = originate_str12; 
    end
    freeswitch.consoleLog("notice", "*********** Dialing Leg1: " .. ostr .. " - Try: "..retries.." ***********\n");
    session1 = freeswitch.Session(ostr);
    local hcause = session1:hangupCause();
    freeswitch.consoleLog("notice", "*********** Leg1: " .. hcause .. " - Try: "..retries.." ***********\n");
until not ((hcause == 'NO_ROUTE_DESTINATION' or hcause == 'RECOVERY_ON_TIMER_EXPIRE' or hcause == 'INCOMPATIBLE_DESTINATION' or hcause == 'CALL_REJECTED' or hcause == 'NORMAL_TEMPORARY_FAILURE') and (retries < max_retriesl1))
if (session1:ready()) then
    -- log to the console
    freeswitch.consoleLog("notice", "*********** Leg1 ("..ostr..") CONNECTED! ***********\n");
    -- Play greeting message
    if (not greeting_snd == "") then
        freeswitch.consoleLog("notice", "*********** Playing greeting sound: "..greeting_snd.." ***********\n");
        --session1:execute("sleep", 100);
        session1:execute("playback", greeting_snd);
    end
    originate_base2 = "{ignore_early_media=true,originate_timeout=90,hangup_after_bridge=true,uuid="..uuid..",leg=2}";
    originate_str2 = originate_base2..dialstr2;
    originate_str22 = originate_base2..dialstr22;
    -- Set recording: uncomment these two lines if you'd like to record the call in stereo (one leg on each channel)
    -- session1:setVariable("RECORD_STEREO", "true");
    -- session1:execute("record_session", "/tmp/"..uuid..".wav");
    -- Set ringback
    session1:setVariable("ringback", "%(2000,4000,440,480)");
    retries = 0;
    session2 = null;
    repeat  
        -- Create session2
        retries = retries + 1;
        if (retries % 2) then 
            ostr2 = originate_str2;
        else 
            ostr2 = originate_str22; 
        end
        freeswitch.consoleLog("notice", "*********** Dialing: " .. ostr2 .. " Try: "..retries.." ***********\n");
        session2 = freeswitch.Session(ostr2, session1);
        local hcause = session2:hangupCause();
        freeswitch.consoleLog("notice", "*********** Leg2: " .. hcause .. " Try: " .. retries .. " ***********\n");
    until not ((hcause == 'NO_ROUTE_DESTINATION' or hcause == 'RECOVERY_ON_TIMER_EXPIRE' or hcause == 'INCOMPATIBLE_DESTINATION' or hcause == 'CALL_REJECTED' or hcause == 'NORMAL_TEMPORARY_FAILURE') and (retries < max_retriesl2))
    if (session2:ready()) then
        freeswitch.consoleLog("notice", "*********** Leg2 ("..ostr2..") CONNECTED! ***********\n");
        freeswitch.bridge(session1, session2);
        -- Hangup session2 if session1 is over
        if (session2:ready()) then 
            session2:hangup(); 
        end
    end
    -- hangup when done
    if (session1:ready()) then session1:hangup(); end
end