[Serusers] RE: [Serdev] LCR-module extension for GW prefixes

[Raymond Chen]

Hi Andrea, 

We've been testing with your patch and so far no major breaks.  Seems to us
that only use load_gw("X") the prefix is inserted.  And also with
load_gw("x") we will have weighted call distribution.  Now we would like to
have the prefix added to the gateways but not the call distribution.  Can
you tell us how to configure that?

Thanks

Ray

-----Original Message-----
From: serdev-bounces at iptel.org [mailto:serdev-bounces at lists.iptel.org] On Behalf
Of Andreas Granig
Sent: Tuesday, March 08, 2005 8:25 PM
To: 'serdev at lists.iptel.org'; 'serusers at lists.iptel.org'
Subject: [Serdev] LCR-module extension for GW prefixes

Hi all,

I've extended Juha's LCR module to support prefixes for gateways.
We use it for prefix-based setting of the bearer capability on our gateways.

Note that the attached patch is against Juha's backport for rel_0_9_0 at 
http://tutpro.com/tmp/lcr-0.9.0.tgz because we've no CVS-HEAD running here.

It works as follows:

In the new table gw_cap you can define capabilities and their 
corresponding prefix, like:

mysql root at ser> select * from gw_cap;
+--------+-----------+------------+----------------------+
| cap_id | cap_value | cap_prefix | cap_description      |
+--------+-----------+------------+----------------------+
|      1 |         1 |            | default phone trunk  |
|      2 |         1 | 01         | prefixed phone trunk |
|      3 |         2 | 02         | prefixed fax trunk   |
+--------+-----------+------------+----------------------+
3 rows in set (0.00 sec)

In this case the cap_value of "1" means phone-capabilites, "2" means 
fax-capabilities.

The table gw_grp is extended with an additional column cap_id.

mysql root at ser> select * from gw_grp;
+--------+-------------------------+--------+
| grp_id | grp_name                | cap_id |
+--------+-------------------------+--------+
|      1 | priority_1_phone        |      1 |
|      2 | priority_1_phone_prefix |      2 |
|      3 | priority_1_fax_prefix   |      3 |
|      4 | priority_2_phone        |      1 |
|      5 | priority_2_phone_prefix |      2 |
|      6 | priority_3_phone_prefix |      2 |
+--------+-------------------------+--------+
6 rows in set (0.00 sec)

In ser.cfg you can then load the gateways for example like this if you 
use different gateways/trunks for phone and fax:

   if( /* phone call */)
   {
     if(!load_gws("1"))
     {
       sl_send_reply("500",
         "Internal server error, unable to load phone gateways");
       break;
     }
   }
   else /* fax call */
   {
     if(!load_gws("2"))
     {
       sl_send_reply("500",
         "Internal server error, unable to load fax gateways");
       break;
     }
   }

The usage of next_gw() is as usual.

Also note that the gateway selection algorithm changes when you use 
load_gws("x") instead of load_gws(): The latter always selects the 
gateways with highest priority first. The new one uses the priority 
value as weight, so also gateways with lower priority are chosen. Hit 
ratio for 5000 rounds is as follows:

priority-1-gw-1: 35%
priority-2-gw-1: 14%
priority-2-gw-3: 14%
priority-2-gw-2: 14%
priority-2-gw-4: 14%
priority-3-gw-1: 9%

Looking forward for comments/fixes/improvements,
Andy