Hello,

 

I've been having some issues with the syntax of Kamailio's config file. I've been following the turorial here: http://kb.asipto.com/asterisk:realtime:kamailio-3.3.x-asterisk-10.7.0-astdb

 

I'd like to setup Kamailio to act as an SBC providing NAT traversal, and security for multiple asterisk boxes on the inside. Currently kamailio has two NIC's, one public and one private. All traffic hits the external interface and is then forwarded to an Asterisk box on the inside.

 

I'd like to modify the config from the tutorial above to support multiple asterisk boxes. Authentication will be done via MySQL and depending on the user domain, the request get's forwarded to the proper Asterisk box. Here is what I've got so far:

 

 if (is_method("REGISTER") && from_uri=~.*@10.55.55.5)
        {
                if(isflagset(FLT_NATS))
                {
                        setbflag(FLB_NATB);
                        # uncomment next line to do SIP NAT pinging
                        ## setbflag(FLB_NATSIPPING);
                }
                if (!save("location"))
                        sl_reply_error();

                route(REGFWD);

                exit;
        }
        else if (is_method("REGISTER") && from_uri=~".*asterisk.domain.tld")
        {
                if(isflagset(FLT_NATS))
                {
                        setbflag(FLB_NATB);
                        # uncomment next line to do SIP NAT pinging
                        ## setbflag(FLB_NATSIPPING);
                }
                if (!save("location"))
                        sl_reply_error();

                route(REGFWDCLOUD);

                exit;
        }
}

 

Based on the domain I route the SIP message to another route block which is esentally the same route block as the origional route[FROMASTERISK] route[TOASTERISK] route[REGFWD]. I beleive there's an easier way of doing this though. Creating separate route blocks per asterisk box would mean creating a new route blocks for each asterisk box. Here's an example:

 

route[FROMASTERISK] {
        if($si==$sel(cfg_get.asterisk.bindip)
                        && $sp==$sel(cfg_get.asterisk.bindport))
                return 1;
        return -1;

# Send to Asterisk
route[TOASTERISK] {
        $du = "sip:" + $sel(cfg_get.asterisk.bindip) + ":"
                        + $sel(cfg_get.asterisk.bindport);
        route(RELAY);
        exit;

# Forward REGISTER to Asterisk
route[REGFWD] {
        if(!is_method("REGISTER"))
        {
                return;
        }
        $var(rip) = $sel(cfg_get.asterisk.bindip);
        $uac_req(method)="REGISTER";
        $uac_req(ruri)="sip:" + $var(rip) + ":" + $sel(cfg_get.asterisk.bindport);
        $uac_req(furi)="sip:" + $au + "@" + $var(rip);
        $uac_req(turi)="sip:" + $au + "@" + $var(rip);
        $uac_req(hdrs)="Contact: <sip:" + $au + "@"
                                + $sel(cfg_get.kamailio.bindip)
                                + ":" + $sel(cfg_get.kamailio.bindport) + ">\r\n";
        if($sel(contact.expires) != $null)
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " + $sel(contact.expires) + "\r\n";
        else
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " + $hdr(Expires) + "\r\n";
        uac_req_send();
}

route[FROMCLOUD] {
        if($si==$sel(cfg_get.cloud.bindip)
                        && $sp==$sel(cfg_get.asterisk.bindport))
                return 1;
        return -1;
}

route[TOCLOUD] {
        $du = "sip:" + $sel(cfg_get.cloud.bindip) + ":"
                        + $sel(cfg_get.asterisk.bindport);
        route(RELAY);
        exit;
}

route[REGFWDCLOUD] {
        if(!is_method("REGISTER"))
        {
                return;
        }
        $var(rip) = $sel(cfg_get.cloud.bindip);
        $uac_req(method)="REGISTER";
        $uac_req(ruri)="sip:" + $var(rip) + ":" + $sel(cfg_get.asterisk.bindport);
        $uac_req(furi)="sip:" + $au + "@" + $var(rip);
        $uac_req(turi)="sip:" + $au + "@" + $var(rip);
        $uac_req(hdrs)="Contact: <sip:" + $au + "@"
                                + $sel(cfg_get.kamailio.bindip)
                                + ":" + $sel(cfg_get.kamailio.bindport) + ">\r\n";
        if($sel(contact.expires) != $null)
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " + $sel(contact.expires) + "\r\n";
        else
                $uac_req(hdrs)= $uac_req(hdrs) + "Expires: " + $hdr(Expires) + "\r\n";
        uac_req_send();
}

 

I'm sure their is any easier way of doing this alhthough I'm not sure how. Can anyone point me in the right direction?

 

Lastly, is there a way to modify the DBURL string on the fly so based on the domain for example, I coudl query a different DB for user credentials?

 

 

Thanks!