[OpenSER-Users] Question regarding usage of carrier-route

[Carsten Bock]

Hi Henning,

Now everything seems to become clear about the usage of the carrierroute
module. Now i seem to understand, how the carrier-route module should
work.

You wrote:
For
"if(!cr_rewrite_uri("0", "call_id")){"
the default-tree would be used (e.g. carrier1).
If i change this to
"if(!cr_tree_rewrite_uri("carrier2", "0")){"
would the tree of "carrier2" be used? I assume (when looking at the
source), i cannot use pseudo-variables here..., right?

Thanks in advance,

Carsten

Am Mittwoch, den 26.09.2007, 13:40 +0200 schrieb Henning Westerholt: 
> On Tuesday 25 September 2007, Carsten Bock wrote:
> > I have a question regarding carrierroute: In table "route_tree" i would
> > have the following:
> > +----+----------+
> > | id | carrier  |
> > +----+----------+
> > |  1 | carrier1 |
> > |  2 | carrier2 |
> > +----+----------+
> >
> > In the table "carrierroute" i have the following:
> > +----+---------+-------------+-------+------+-------+---------------+
> > | id | carrier | scan_prefix | level | prob | strip | rewrite_host  |
> > +----+---------+-------------+-------+------+-------+---------------+
> > |  1 |       1 | 49          | 0     |  0.5 | 0     | gateway1_1    |
> > |  2 |       1 | 49          | 0     |  0.5 | 0     | gateway1_2    |
> > |  3 |       1 | 49          | 1     |    1 | 0     | gateway1_3    |
> > |  4 |       1 | 49          | 2     |    1 | 0     | gateway1_4    |
> > |  5 |       2 | 49          | 0     |    1 | 0     | gateway2_1    |
> > |  6 |       2 | 49          | 1     |    1 | 0     | gateway2_2    |
> > +----+---------+-------------+-------+------+-------+---------------+
> >
> > in the routing logic i would do the following:
> >
> > route {
> > 	# Calls to PSTN based on RURI
> > 	if(!cr_rewrite_uri("carrier1", "call_id")){
> > 		sl_send_reply("403", "Not allowed");
> > 	} else {
> > 		# In case of failure, re-route the request
> > 		t_on_failure("1");
> > 		# Relay the request to the gateway
> > 		t_relay();
> > 	}
> > }
> >
> > failure_route(1) {
> > 	# In case of failure, send it to an alternative route:
> > 	if (t_check_status("408|5[0-9][0-9]")) {
> > 		if(!cr_rewrite_uri("carrier1", "call_id")){
> > 			t_reply("403", "Not allowed");
> > 		} else {
> > 			t_on_failure("1");
> > 			t_relay();
> > 		}
> > 	}
> > }
> >
> > Questions:
> > 1) Is this configuration right?
> 
> Hell Carsten,
> 
> well, you should specify the level in cr_rewrite_uri, not the carrier. The 
> mapping of users to a certain carrier is specified in the cr_prefered_carrier 
> column, e.g. in subscriber. But for cr_rewrite_uri only the default carrier 
> is used. 
> 
> This column is not yet created by the database scripts. Perhaps it makes sense 
> to extend this table, if the extra modules are installed like the SERWEB 
> case.
> 
> So for example you could do this:
> 
> route {
>         # route calls based on hash over callid
>         # choose route level 0 of the default carrier
>         if(!cr_rewrite_uri("0", "call_id")){
>                 sl_send_reply("403", "Not allowed");
>         } else {
>                 # In case of failure, re-route the request
>                 t_on_failure("1");
>                 # Relay the request to the gateway
>                 t_relay();
>         }
> }
> 
> failure_route(1) {
>         # In case of failure, send it to an alternative route:
>         if (t_check_status("408|5[0-9][0-9]")) {
>                 #choose route level 1 of the default carrier
>                 if(!cr_rewrite_uri("1", "call_id")){
>                         t_reply("403", "Not allowed");
>                 } else {
>                         t_on_failure("2");
>                         t_relay();
>                 }
>         }
> }
> 
> failure_route(2) {
>         # further processing
> }
> 
> > 2) Would the call, in this case, go to either gateway1_1 or gateway1_2, in
> > case of failure to gateway1_3? 
> 
> The calls (with the config snippet above) would be in the routed to gateway1_1 
> or gateway1_2, depending of the hash of the callid. If you get an failure, 
> the next (in this case) level of the routing tree is choosen, e.g. gateway1_3 
> or gateway1_4.
> 
> > 3) In case all three fail, it would go to 
> > gateway1_4? (original route would be level 1, 1st failure-route would be
> > level 2, 2nd failure-route would be level 3 and so on?)
> 
> You must manually choose another level. You can choose the levels as you like, 
> or choose another carrier with the rewrite_tree function.
> 
> > 4) Calls to other 
> > destinations as to destinations starting with "49" in the URI would be
> > rejected, right? 
> Yes, if you don't have a route with an empty prefix in this tree. You could 
> also block certain prefixes if you specify an empty rewrite.
> 
> > 5) Does it cause problems, when "prob" does not result in 
> > 1? E.g. does a prob of 1 and 1 result into the same as 0.5 and 0.5?
> 
> Yes, this is the same. The actual prob values are "fixed", as you could see in 
> the cr_dump_routes output.
> 
> I've extended the carrierroute documentation somewhat with the points you 
> mentioned, i hope that its now more clear.
> 
> Cheers,
> 
> Henning