[Freeswitch-users] Newbie question: Executing Lua scripts for incoming calls, how concurrency is to be handled?

Fri Dec 21 02:23:01 MSK 2012

Hi Michael,

Thanks for the reply, and the suggestions.

My current implementation is a similar to what you have suggested, i.e.:

1.       I have defined 4 sets of global variables in vars.xml, where each set keeps a track of port's status and last used timestamp

2.       In the dialplan, I execute a simple Lua script which 'chooses' the line based on global variables status and timestamp (using "global_getvar") and update the status of the line to be used (using "global_setvar")

3.       Bridge to the line returned by the above script

4.       Execute another Lua script on hang-up, which updates the global variables (status and timestamp)

If I were to implement the hash way, I would have to probably do the following:

1.       In the dialplan, I execute a simple Lua script which 'chooses' the line by reading the hash values of the line status and timestamp and update the hash status of the line to be used

2.       Bridge to the line returned by the above script

3.       Execute another Lua script on hang-up, which updates the hash values (status and timestamp)

But I am still not clear on the concurrency question - if FreeSWITCH has received 2 calls at the same time on the E1 line, should I be worried about protecting the script that gets executed to access the hash, decide on the line to be used, and then update the hash?

Thanks again!

With regards,
Sirish

From: freeswitch-users-bounces at lists.freeswitch.org [mailto:freeswitch-users-bounces at lists.freeswitch.org] On Behalf Of Michael Collins
Sent: Friday, 21 December 2012 3:42 AM
To: FreeSWITCH Users Help
Subject: Re: [Freeswitch-users] Newbie question: Executing Lua scripts for incoming calls, how concurrency is to be handled?

Sirish,

Since you're using an E1 to connect to the PBX then really all you need to do is keep track of the last time each port was hung up and whether or not a given port is currently in use. I would use api_on_answer to launch a simple script to set a flag to say that a particular port is in use and then use the api_hangup_hook to launch another script when the call ends.

The channel variables page on the wiki has some examples of how to use these. I recommend that you write simple Lua scripts that use the "hash" API to store information in the local database. Also, check out the "hash_dump" API as it is a useful way to quickly see what all is stored there.

For an example of how to add, remove, and read information from the local database using the "hash" API please see conf/dialplan/default.xml. Search for "hash" and you'll see all sorts of examples of how the example dialplan uses the local database to store useful information that allows us to implement features like call return, call intercept, etc.

-MC
On Tue, Dec 18, 2012 at 7:39 PM, Sirish Masur Mohan <Sirish.MasurMohan at oa.com.au<mailto:Sirish.MasurMohan at oa.com.au>> wrote:
Hi Michael,

>> How are you physically connecting from FreeSWITCH to the PBX?

I connect this via E1 link - I have a Sangoma card installed on the FreeSWITCH machine.

With regards,
Sirish

From: freeswitch-users-bounces at lists.freeswitch.org<mailto:freeswitch-users-bounces at lists.freeswitch.org> [mailto:freeswitch-users-bounces at lists.freeswitch.org<mailto:freeswitch-users-bounces at lists.freeswitch.org>] On Behalf Of Michael Collins
Sent: Wednesday, 19 December 2012 1:31 PM
To: FreeSWITCH Users Help
Subject: Re: [Freeswitch-users] Newbie question: Executing Lua scripts for incoming calls, how concurrency is to be handled?

To trigger SIP registrations you'd need the PBX to have a SIP client. I'm assuming this is possible, but maybe that's a false assumption. How are you physically connecting from FreeSWITCH to the PBX?

-MC
On Tue, Dec 18, 2012 at 2:36 PM, Sirish Masur Mohan <Sirish.MasurMohan at oa.com.au<mailto:Sirish.MasurMohan at oa.com.au>> wrote:
Hey Guys,

Would really appreciate if you could help me out here - isn't there a way to handle concurrent calls in the dial plan, especially when Lua scripts, accessing global variables, are executed on receiving calls?

Is mod_fifo the closest I could get to handle concurrency (as Michael has explained)? If yes, how do I trigger SIP registrations, especially working with a PBX which I don't have full control of?

With regards,
Sirish

From: Sirish Masur Mohan
Sent: Tuesday, 18 December 2012 1:02 PM
To: FreeSWITCH Users Help
Subject: RE: [Freeswitch-users] Newbie question: Executing Lua scripts for incoming calls, how concurrency is to be handled?

Hi Michael,

Thanks for the reply.

>> You would need a SIP registration from the PBX to FreeSWITCH for each of the modem extensions
I am seen SIP clients such as X-Lite sending out the SIP registrations, but could you please clarify as to how this can be achieved in the PBX? The final production environment would be out in the customer's PBX, which I may not have complete control of..

>> What application are you building?
I may not be able to provide the details because of the NDA with customer, but what I am trying to achieve is, to replace an existing IVR with FreeSWITCH in an old existing setup of the customer - that's the reason why we continue working with dialup modems!

With regards,
Sirish

From: freeswitch-users-bounces at lists.freeswitch.org<mailto:freeswitch-users-bounces at lists.freeswitch.org> [mailto:freeswitch-users-bounces at lists.freeswitch.org] On Behalf Of Michael Collins
Sent: Tuesday, 18 December 2012 6:23 AM
To: FreeSWITCH Users Help
Subject: Re: [Freeswitch-users] Newbie question: Executing Lua scripts for incoming calls, how concurrency is to be handled?

You don't have to have actual human agents for mod_fifo. You could define a user for each modem and then manually "log in" those "agents" on the command line using the fifo_member API command. Something like this:

fifo_member add fifo_name {fifo_member_wait=nowait}user/1234

Where 1234 is the user id of one of the modems. You would need a SIP registration from the PBX to FreeSWITCH for each of the modem extensions.

Having modems go through a VoIP system sounds a bit scary. What application are you building?
-MC
On Sun, Dec 16, 2012 at 5:41 PM, Sirish Masur Mohan <Sirish.MasurMohan at oa.com.au<mailto:Sirish.MasurMohan at oa.com.au>> wrote:
Hi William,

Thanks for the reply.

My setup is as follows:
Client(Caller)->dialup modem->PBX->FreeSWITCH->PBX-> 4 dialup modems->Server(Receiver)

I basically need FreeSWITCH to bridge the incoming call to the best external destination (out of the 4 available), so that the modem training, connection etc can take place smoothly, before exchange of data. I am not sure if mod_fifo would help me in this scenario, as, I would require an agent to dial in and read the fifo. Could you please clarify?

Thanks!

With regards,
Sirish

-----Original Message-----
From: freeswitch-users-bounces at lists.freeswitch.org<mailto:freeswitch-users-bounces at lists.freeswitch.org> [mailto:freeswitch-users-bounces at lists.freeswitch.org<mailto:freeswitch-users-bounces at lists.freeswitch.org>] On Behalf Of William King
Sent: Monday, 17 December 2012 10:47 AM
To: freeswitch-users at lists.freeswitch.org<mailto:freeswitch-users at lists.freeswitch.org>
Subject: Re: [Freeswitch-users] Newbie question: Executing Lua scripts for incoming calls, how concurrency is to be handled?

Sounds like you want to take a look into mod_fifo.

William King
Senior Engineer
Quentus Technologies, INC
1037 NE 65th St Suite 273
Seattle, WA 98115
Main:   (877) 211-9337<tel:%28877%29%20211-9337>
Office: (206) 388-4772<tel:%28206%29%20388-4772>
Cell:   (253) 686-5518<tel:%28253%29%20686-5518>
william.king at quentustech.com<mailto:william.king at quentustech.com>
_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
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--
Michael S Collins
Twitter: @mercutioviz
http://www.FreeSWITCH.org
http://www.ClueCon.com
http://www.OSTAG.org

_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting at freeswitch.org<mailto:consulting at freeswitch.org>
http://www.freeswitchsolutions.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
FreeSWITCH-users at lists.freeswitch.org<mailto:FreeSWITCH-users at lists.freeswitch.org>
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org

--
Michael S Collins
Twitter: @mercutioviz
http://www.FreeSWITCH.org
http://www.ClueCon.com
http://www.OSTAG.org

_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting at freeswitch.org<mailto:consulting at freeswitch.org>
http://www.freeswitchsolutions.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
FreeSWITCH-users at lists.freeswitch.org<mailto:FreeSWITCH-users at lists.freeswitch.org>
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org

--
Michael S Collins
Twitter: @mercutioviz
http://www.FreeSWITCH.org
http://www.ClueCon.com
http://www.OSTAG.org

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