Hello Bogdan,

From a PSTN point of view, a channel is allocated right at the

beginning of the call (before ringing) If I have a gateway that if offering me 1000 channels and I don't want to saturate the gateway, I need to add channels to the profile right after the INVITE is sent and decrement them when the call is terminated. Like this I can keep track of the channel utilization per gateway and do proper failover between gateways.

Regards, Ovidiu Sas

On Fri, Jun 20, 2008 at 7:04 AM, Bogdan-Andrei Iancu bogdan@voice-system.ro wrote:

Hi Ovidiu,

why don't you add the dialog to the profile when you receive the 200 OK in reply route ?

Regards, Bogdan

Ovidiu Sas wrote:

...

Hello Bogdan,

I started to play with the new profiling feature and tested a few scenarios.

Scenario 1: UserA calls UserB. UserB has call forward no answer configured and activated. For the first call (UserA to UserB) I tag the call with profile [caller, UserA]. When the call is forwarded from UserB to UserC, I re-tag the call with profile [caller, UserB]. Inspecting the profile counters via the MI interface I can see that both subprofiles are incremented with 1. This works fine for this scenario.

Scenario 2: UserA makes a call to PSTN. I have two gateways configured for outgoing calls to PSTN. First, the call is routed to GW1 and therefore I tag the the call with profile [outgoing, GW1]. Let's suppose that GW1 is unreachable or to busy to handle new requests, and therefore I will failover the call to GW2. In this case, I will re-tag the call with profile [outgoing, GW2]. For this scenario, I would like to keep in the profile "outgoing" the the number of active calls to each gateway. I think we need a new function that will give the ability to reset a previous profile for the existing dialog. Before re-routing the call to the second gateway, I would like to have the ability to reset the previous profile set for the previous gateway so I can have accurate numbers of calls per gateway.

Regards, Ovidiu Sas

On Mon, Jun 2, 2008 at 11:07 AM, Bogdan-Andrei Iancu bogdan@voice-system.ro wrote:

...

Hi,

I just committed in SVN trunk (1.4, next major release) support for dialog profiling.

What dialog profiling is

Dialog profiling is a mechanism that helps in classifying, sorting and keeping trace of certain types of dialogs, using whatever properties of the dialog (like caller, destination, type of calls, etc). Dialogs can be dynamically added in different (and several) profile tables - logically, each profile table can have a special meaning (like dialogs outside the domain, dialogs terminated to PSTN, etc). Information provided by the profiles can be used also for doing real load-balancing - by real, I mean routing decisions based on load. So far dispatcher module can do probabilistic dispatching with no feedback on the actual load of the peer (or about the call success). See example 3 - load balancing between 2 asterisk boxes with identical capacities.

Being able to actually trace the ongoing dialog, gives liberty to do more complex routing logics.

There are two types of profiles:

• with no value - a dialog simply belongs to a profile. (like outbound calls profile). There is no other additional information to describe the dialog's belonging to the profile;
• with value - a dialog belongs to a profile having a certain value (like in caller profile, where the value is the caller ID). The belonging of the dialog to the profile is strictly related to the value.

A dialog can be added to multiple profiles in the same time.

What it should be used for

Example 1:

Count the calls terminating to PSTN in order to monitor the load. Before routing the call the GW, check if the number of ongoing calls (to the GW) do not exceed some value.

modparam("dialog","profiles_no_value","pstn_calls") .... /* do some checking */ get_dialog_size("pstn_calls","$avp(cnt)"); if ( $avp(cnt) > 32 ) { sl_send_reply("500","GW full"); exit; } set_dlg_profile("pstn_calls"); /* route to the GW */ .....

Example 2:

Allow only 2 parallel calls per user - use a profile with value to count the outgoing calls for each subscriber

modparam("dialog","profiles_with_value","caller") .... /* do some checking */ get_dialog_size("caller","$fu","$avp(cnt)"); if ( $avp(cnt) > 2 ) { sl_send_reply("403","Not allowed"); exit; } set_dlg_profile("caller","$fu"); /* route the call */ .....

Example 3:

Do load balancing between 2 asterisk boxes with identical capacities - use a profile with values to count the ongoing calls through each Asterisk box.

modparam("dialog","profiles_with_value","asterisk") .... /* do some checking */ get_dialog_size("asterisk","box1","$avp(cnt1)"); get_dialog_size("asterisk","box2","$avp(cnt2)");

if ( $avp(cnt1) > $avp(cnt2) ) { setdsturi("sip:IP_BOX2:PORT_BOX2"); set_dlg_profile("asterisk","box2"); } else { setdsturi("sip:IP_BOX1:PORT_BOX1"); set_dlg_profile("asterisk","box1"); } /* route the call */ .....

Of course, this can be extended for asymmetric load or for multiple boxes.

Regards, Bogdan

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