[OpenSIPS-Users] B2b module topology hiding

[Jeff Pyle]

Doug,

It sounds like the request domain is the same when you call b2b_init as it does when it enters your core route.  You may want to amend your Destination URI xlog to display $rd as well.  Or, perhaps try some testing by manually updating it to see if things improve.



- Jeff


On May 25, 2010, at 2:39 PM, Douglas Lane wrote:

> Hi All,
> 
> I've decided to embark on a new little project, and that is turning 
> opensips into a very basic sbc-type function. The architecture is simple:
> 
> UAC ------------- (public internet) ------> OpenSIPS SBC -------- 
> (private network) -------> OpenSIPS Router ----------> Asterisk ------> PSTN
> 
> The concept here is to have the OpenSIPS SBC to act as a registrar and 
> initial auth server (so this system will handle the Proxy Auth process). 
> Once the auth is successful, the idea is then to push the request 
> through the B2B module and relay it onto the OpenSIPS Router server, 
> which will handle any possible rewrites to the SIP messages before 
> sending the call to an Asterisk box for termination.
> 
> The reason to use the B2B module is to hide the topology (like a SBC does).
> 
> Now I've got a functional route logic programmed on both systems, and if 
> I remove the b2b stuff, the calls go through correctly. When I add in 
> the b2b stuff accordingly, After the b2b module is started, the OpenSIPS 
> SBC box sends an invite to itself on its public interface. The initial 
> invite from the UAC passes down to the Router and finally onto the 
> Asterisk box correctly, but the SBC gets a bit confused with all these 
> invites coming into itself from itself.
> 
> I was wondering if anyone has a working example of an architecture 
> similar to the above, or could point me in the right direction. What I 
> have noticed is the following just below before we get an invite from 
> ourselves:
> 
> May 25 20:22:20 [2268] DBG:b2b_entities:client_new: generated tag = 
> [NmZlZDUxNjM1ZjMwNzg2N2JjMjllZjYwZTUyN2UyYzE.7d70bc67]
> May 25 20:22:20 [2268] DBG:tm:t_uac: 
> next_hop=<sip:0716054314 at dev.mydomain.com>
> May 25 20:22:20 [2268] DBG:core:mk_proxy: doing DNS lookup...
> May 25 20:22:20 [2268] DBG:core:sip_resolvehost: no port, no proto -> do 
> NAPTR lookup!
> May 25 20:22:20 [2268] DBG:core:get_record: lookup(dev.mydomain.com, 35) 
> failed
> May 25 20:22:20 [2268] DBG:core:sip_resolvehost: no valid NAPTR record 
> found for dev.mydomain.com trying direct SRV lookup...
> May 25 20:22:20 [2268] DBG:core:do_srv_lookup: 
> SRV(_sip._udp.dev.mydomain.com) = sbc1.dev.mydomain.com:5060
> May 25 20:22:20 [2268] DBG:core:get_out_socket: socket determined: 0x7912f8
> May 25 20:22:20 [2268] DBG:tm:dlg2hash: 42135
> May 25 20:22:20 [2268] DBG:tm:print_request_uri: 
> sip:0716054314 at dev.mydomain.com
> May 25 20:22:20 [2268] DBG:tm:t_uac: REF_UNSAFE: after is 1
> May 25 20:22:20 [2268] DBG:tm:set_timer: relative timeout is 500000
> May 25 20:22:20 [2268] DBG:tm:insert_timer_unsafe: [4]: 0x7faf39600988 
> (12600000)
> May 25 20:22:20 [2268] DBG:tm:set_timer: relative timeout is 30
> May 25 20:22:20 [2268] DBG:tm:insert_timer_unsafe: [0]: 0x7faf396009b8 (42)
> May 25 20:22:20 [2268] DBG:b2b_logic:b2bl_create_new_entity: address: 
> 0x7faf396022d0
> 
> It looks like the b2b module initiates a lookup on the domain and then 
> I'd assume sends the invite to itself as sbc1.dev.mydomain.com points to 
> the SBC's public IP address.
> 
> And then directly after the above, my script kicks in:
> 
> [SBC] Setting the on_reply and failure route settings
> [SBC] Sending the request to the core
> Request leaving server, D-URI='sip:172.20.0.21:5060' - M=INVITE 
> RURI=sip:0716054314 at dev.mydomain.com F=sip:doug at dev.mydomain.com 
> T=sip:0716054314 at dev.mydomain.com IP=1.2.3.4 
> ID=NmZlZDUxNjM1ZjMwNzg2N2JjMjllZjYwZTUyN2UyYzE.
> 
> Any suggestions?
> 
> This is what my route logic looks like after the INVITE has been 
> processed (proxy auth):
> 
> route[CORE]
> {
>         ds_select_dst("2", "0");
>         xlog("L_INFO", "[SBC] Destintion URI now set to $du\n");
> 
>         xlog("L_INFO", "[SBC] Calling b2b module with topology hiding\n");
>         b2b_init_request("top hiding");
> 
>         xlog("L_INFO", "[SBC] Setting the on_reply and failure route 
> settings\n");
>         t_on_reply("1");
>         t_on_failure("1");
> 
>         xlog("L_INFO", "[SBC] Sending the request to the core\n");
>         xlog("L_INFO", "Request leaving server, D-URI='$du' - M=$rm 
> RURI=$ru F=$fu T=$tu IP=$si ID=$ci\n");
>         if(!t_relay("0x05"))
>         {
>                 sl_reply_error();
>         }
>         exit;
> }
> 
> I also tried using forward() instead of t_relay(), but both seem to have 
> the same affect.
> 
> As always, your assistance is greatly appreciated.
> 
> Thanks
> Doug
> 
> 
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