[SR-Users] call forking using dbaliases not working for un-NATed clients
Klaus Darilion
klaus.mailinglists at pernau.at
Wed Sep 19 17:23:30 CEST 2012
On 19.09.2012 16:13, Yufei Tao wrote:
> I should have made it clearer: $du is null both before and after lookup
> location in LOCATION_BRANCH when no fix_nated_register was done (thus
> 'received' column in location table was null). When fix_nated_register
> was done, $du for each branch was null before lookup location, but set
> to 'received' after lookup location as you said. But in this case
> (fix_nated_register done), everything works fine.
>
> So seems now the problem happens when: 'received' in location table is
> null, causing $du not to be set. I used to think $du is only set by
> record-route and thanks for clarifying this :)
>
> Even when without fix_nated_register (thus no 'received'), the lookup
> location for each branch, i.e. y2 and y3, set $ru to the 'contact' field
> successfully, but $du isn't set. But Kamailio did relay to the first
> branch (trunk?) and not the others. So the first branch is handled
> differently? So maybe when $du is null, should set it to $ru on the
> branches?
There is no need to set $du. If $du is null, $ru is used for routing.
Can you verify with ngrep/tcpdump (capture on 'any' interface) if there
is no SIP message sent to y2/y3 or the message is sent, but to wrong
destination (e.g. same target as first branch).
regards
Klaus
>
> Yufei
>
>
> On 19/09/12 11:53, Klaus Darilion wrote:
>>
>>
>> On 19.09.2012 12:24, Yufei Tao wrote:
>>> Hi Klaus
>>>
>>> Thanks for the reply!
>>>
>>> I check the $du, it is always null before and after the lookup. Is it
>>> only set when relaying to a proxy (from record-route), and not to a
>>> client?
>>
>> That's strange. For NATed clients, $du must contain the 'received'
>> URI. Otherwise they can not be contacted as $ru contains the private
>> IP address.
>>
>>> When no fix_nated_register is called, the lookup location for both
>>> clients y2 and y3 is successful from the log, when printing out $ru
>>> after lookup. But seems Kamailio only relays to one client's IP while
>>> not others. I think there must be some differences when branch route is
>>> executed first time and second time as you said. As it feels like for
>>> the first branch (trunk?) it used the 'contact' column from the location
>>> table, and for the other branches, it tries to use 'received'?
>>
>> It seems db_lookup() creates multiple branches. Is lookup() only
>> finding 1 contact in table or multiple contacts?
>>
>> regards
>> Klaus
>>
>>>
>>>
>>> Yufei
>>>
>>> On 18/09/12 18:49, Klaus Darilion wrote:
>>>> I suspect that the branch route is first executed for the NATed
>>>> client. Then the 'received' column is used as destination URI. When
>>>> executing the branch route again, the destination URI is still the
>>>> value from the previous branch, and lookup() will not overwrite is as
>>>> 'received' is not available. Then Kamailio sends the INVITE again to
>>>> the first client.
>>>>
>>>> You can try to set $du to Null before lookup(). ($du=null or
>>>> $du=$null, not sure what the correct syntax is).
>>>>
>>>> Another workaround is to use fix_nated_register() for every client
>>>> (the pragmatic and more secure approach).
>>>>
>>>> regards
>>>> Klaus
>>>>
>>>> On 18.09.2012 15:16, Yufei Tao wrote:
>>>>> Hi
>>>>>
>>>>> I have a strange problem on forking calls to a group of users. For
>>>>> example I have two users y2 and y3 in dbaliases, both with
>>>>> alias_username 'group'. And y2 and y3 both registers with Kamailio
>>>>> fine.
>>>>> When I make a call to 'group' from a third client y1, what my
>>>>> kamailio.cfg does is: do an alias_db_lookup("dbaliases"), and goes to
>>>>> BRANCH_ALIASDB, where a lookup location will be done for each of the
>>>>> username resulting from lookup of dbaliases, something like this:
>>>>>
>>>>> y1--INVITE 'group'-->lookup
>>>>> dbaliase-->[BRANCH_ALIASDB]--->'y2'-->lookup
>>>>> location---¬
>>>>>
>>>>> | |-->relay
>>>>>
>>>>> ---->[BRANCH_ALIASDB]--->'y3'-->lookup
>>>>> location----
>>>>>
>>>>> The all works well as long as all clients are NAT'ed. However when
>>>>> they
>>>>> are not NAT'ed, e.g. all on the same LAN with Kamailio, the call only
>>>>> goes to one of the group members, e.g. y2 only. When checking the log,
>>>>> it seemed to have done the dbaliases lookup fine, and each location
>>>>> lookup successfully. But Kamailio only relayed y2's IP, e.g. to the
>>>>> client, while y3's to itself.
>>>>>
>>>>> When comparing the location table when clients are NAT'ed or not, I
>>>>> find
>>>>> that the 'received' column is only populated when I do
>>>>> fix_nated_register. And group calls only works when 'received'
>>>>> column is
>>>>> populated. That explains why when clients are NAT'ed group calls work,
>>>>> as I only do fix_nated_register if nat_uac_test returns true.
>>>>>
>>>>> But if this is the only reason, if two clients register using the same
>>>>> username, e.g. both as y3, and when 'received' column of location
>>>>> table
>>>>> is empty (no fix_nated_register done), I would expect a call to y3
>>>>> should also only make 1 client ring. But in fact both of them rang!
>>>>> The
>>>>> flow is like:
>>>>>
>>>>> y1--INVITE 'y3'-->lookup location for 'y3'----> IP of 1st client
>>>>> registered as 'y3'
>>>>> |
>>>>> ---> IP of 2nd client
>>>>> registered as 'y3'
>>>>>
>>>>> While a call to 'group' (thus dbaliases lookup took place) under such
>>>>> un-NAT'ed set up made only 1 client ring.
>>>>>
>>>>> So I can make it work by always doing fix_nated_register. But I'm not
>>>>> clear about these things:
>>>>> - why does a lookup of dbaliases before lookup of location make such
>>>>> difference?
>>>>> - does lookup location work differently depending on whether it is
>>>>> called from trunk or from a route called from a branch route?
>>>>>
>>>>>
>>>>> Following is relevant parts from my config file:
>>>>>
>>>>> #############################################################
>>>>> route[LOCATION]
>>>>> {
>>>>> if ( alias_db_lookup("dbaliases") )
>>>>> {
>>>>> t_on_branch("BRANCH_ALIASDB"); # in
>>>>> branch_route[BRANCH_ALIASDB],
>>>>> # call another route that
>>>>> looks up
>>>>> location,
>>>>> # if not existent, call drop()
>>>>>
>>>>> }
>>>>> else
>>>>> {
>>>>> xlog("L_DBG","LOCATION: not alias - go to lookup location
>>>>> trunk\n");
>>>>> route(LOCATION_TRUNK); # normal look up location and sending of
>>>>> 404 etc
>>>>> }
>>>>>
>>>>> ... ...
>>>>> }
>>>>> #############################################################
>>>>> branch_route[BRANCH_ALIASDB]
>>>>> {
>>>>> xlog("L_DBG", "BRANCH_ALIASDB: $fU@$fd -> $rU@$rd;
>>>>> Method:$rm\n");
>>>>> route(LOCATION_BRANCH);
>>>>> }
>>>>>
>>>>> route[LOCATION_BRANCH]
>>>>> {
>>>>> if (!lookup("location"))
>>>>> {
>>>>> # Drop this branch - it's going nowhere
>>>>> drop();
>>>>> }
>>>>> }
>>>>> #############################################################
>>>>> route[RELAY] {
>>>>> xlog("L_DBG","RELAY: method=$rm, callid=$ci, cseq=$cs\n");
>>>>>
>>>>>
>>>>> #!ifdef WITH_NAT
>>>>> if (check_route_param("nat=yes")) {
>>>>> setbflag(FLB_NATB);
>>>>> }
>>>>> if (isflagset(FLT_NATS) || isbflagset(FLB_NATB)) {
>>>>> xlog("L_DBG", "RELAY: about to call RTPPROXY\n");
>>>>> route(RTPPROXY);
>>>>> }
>>>>> #!endif
>>>>>
>>>>> /* example how to enable some additional event routes */
>>>>> if (is_method("INVITE")) {
>>>>> t_on_reply("REPLY_ONE");
>>>>> t_on_failure("FAIL_ONE");
>>>>> }
>>>>>
>>>>> if (!t_relay()) {
>>>>> sl_reply_error();
>>>>> }
>>>>>
>>>>> exit;
>>>>> }
>>>>>
>>>>> ############################################################
>>>>> route[NAT] {
>>>>> #!ifdef WITH_NAT
>>>>> xlog("L_DBG","NAT: method=$rm, callid=$ci, cseq=$cs\n");
>>>>>
>>>>> force_rport();
>>>>> if (nat_uac_test("2")) {
>>>>> if (method=="REGISTER") {
>>>>> fix_nated_register();
>>>>> xlog("L_DBG","NAT: Just done fix_nated_register in
>>>>> REGISTER
>>>>> message in NAT route\n");
>>>>> } else {
>>>>> xlog("L_DBG","NAT: fix_nated_contact\n");
>>>>> fix_nated_contact();
>>>>> }
>>>>> setflag(FLT_NATS);
>>>>> }
>>>>>
>>>>> # setflag(FLT_NATS); ## -- YT: set NAT flag for all, so will force
>>>>> media relay
>>>>> #!endif
>>>>> return;
>>>>> }
>>>>>
>>>>> #############################################################
>>>>> And in the main route, route LOCATION and RELAY are the last two
>>>>> routes:
>>>>> route {
>>>>> ...
>>>>> route(NAT);
>>>>>
>>>>> ... ...
>>>>>
>>>>> # user location service
>>>>> route(LOCATION);
>>>>>
>>>>> route(RELAY);
>>>>> }
>>>>>
>>>>> Hope I have made it clear. Thanks very much!
>>>>>
>>>>> Yufei
>>>>> --
>>>>> Yufei Tao
>>>>> Red Embedded
>>>>>
>>>>> This E-mail and any attachments hereto are strictly confidential and
>>>>> intended solely for the addressee. If you are not the intended
>>>>> addressee please notify the sender by return and delete the message.
>>>>>
>>>>> You must not disclose, forward or copy this E-mail or attachments to
>>>>> any third party without the prior consent of the sender.
>>>>>
>>>>> Red Embedded Design, Company Number 06688253 Registered in England:
>>>>> The Waterfront, Salts Mill Rd, Saltaire, BD17 7EZ
>>>>>
>>>>> _______________________________________________
>>>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing
>>>>> list
>>>>> sr-users at lists.sip-router.org
>>>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>>>>
>>>
>>> --
>>> Yufei Tao
>>> Red Embedded
>>>
>>> This E-mail and any attachments hereto are strictly confidential and
>>> intended solely for the addressee. If you are not the intended
>>> addressee please notify the sender by return and delete the message.
>>>
>>> You must not disclose, forward or copy this E-mail or attachments to
>>> any third party without the prior consent of the sender.
>>>
>>> Red Embedded Design, Company Number 06688253 Registered in England:
>>> The Waterfront, Salts Mill Rd, Saltaire, BD17 7EZ
>>>
>
> --
> Yufei Tao
> Red Embedded
>
> This E-mail and any attachments hereto are strictly confidential and intended solely for the addressee. If you are not the intended addressee please notify the sender by return and delete the message.
>
> You must not disclose, forward or copy this E-mail or attachments to any third party without the prior consent of the sender.
>
> Red Embedded Design, Company Number 06688253 Registered in England: The Waterfront, Salts Mill Rd, Saltaire, BD17 7EZ
>
More information about the sr-users
mailing list