[Serusers] Problem : Can SER process the reINVITE messages properly?
Greger V. Teigre
greger at teigre.com
Mon Aug 1 02:19:11 CEST 2005
Ricardo,
I think you are correct in your analysis of mediaproxy not accepting a third
party. Also, I saw the post from somebody on the newest mediaproxy version.
Have you tried it? Version 1.2.1 created a new session for reINVITEs,
that's why the nat=yes is used in the ONsip.org configs. Version 1.3.0 added
support for detecting that a reINVITE came in and would reuse the session
(which I btw don't think is good for your scenario as you change the IP).
1.4.2 seems to address your problem, so it would be interesting to hear if
you have any success.
As for the reINVITE with the IP address instead of domain, that's ok.
g-)
Ricardo Martinez wrote:
> Hello Greger and SER users.
> About this issue here are some test that i made. I added the
> lookup("location") as you recommend me :
>
> #
>
>
>
> ----------------------------------------------------------------- #
> Loose Route Section #
> ----------------------------------------------------------------- if
> (loose_route()) {
>
> if (has_totag() && (method=="INVITE" ||
> method=="ACK")) { lookup("location");
> if (isflagset(6) || client_nat_test("3") ||
> search("^Route:.*;nat=yes")){
> setflag(6);
> use_media_proxy();
> };
> };
>
> route(1);
> break;
> };
>
>
> Unfortunately, i'm still unable to have voice in both ways, but this
> modification seems to handle better the reINVITE message. And this
> is why. For the normal approach (i mean the initial onsip_pstn
> configuration) the second INVITE was not using the mediaproxym as
> Greger pointed. Now, as you can see in the debugs that i'm
> attaching, the second invite is using the mediaproxy, and therefore
> the "c" parameter in the SDP message is being correctly modified by
> SER. So, i don't understand why this time the call is failing. Could
> it be that mediaproxy is not capable to handle the reINVITEs?. For
> example in the debug from mediaproxy (i'm also attaching this one), i
> see a warning message like this : warning: Received packet from a
> third party: 200.0.0.7:16432. It seems like mediaproxy is not
> accepting "voice packets" from the second IP (the one indicated by
> the reINVITE). Why?
> Also, when the call is established this is the output from the
> "session" command :
>
> Caller Via Called
> Status Duration Codec Type Traffic
> ----------------------------------------------------------------------------
> --------------------------------------
> 200.0.0.6:17480 - 200.0.0.5:35094 - 200.0.0.4:46115 inactive
> 0'24" G729 Audio 0/16.75k/16.75k
>
> The call is established but between the first IP (Asterisk box) and
> the endpoint public IP.
> So, could this be a problem with mediaproxy?. I read the changelog
> from the version 1.3.1 and this is what i found :
>
> Changes from version 1.2.1 to 1.3.0
> -----------------------------------
>
> - Only create a new session if a request belongs to the first INVITE
> (no longer creates new sessions on re-INVITEs)
>
> could it be related?.
>
> I also have a general question about the reINVITE. As you can see
> the first INVITE has in his URI the domain name for the number :
> 5555848114 at sipvoiss.desarrollo.redvoiss.net (Frame 1 from the debug).
> The reINVITE sent by Asterisk has the URI : 5555848114 at 200.0.0.4. Is
> this ok?, despite of this the reINVITE is correctly redirected to the
> endpoint. (You can check this in the frame 13 from the debug).
>
> Thanks again.
>
> Regards,
>
> Ricardo Martinez.-
>
>
>
>> -----Mensaje original-----
>> De: Greger V. Teigre [mailto:greger at teigre.com]
>> Enviado el: Miércoles, 20 de Julio de 2005 3:06
>> Para: Ricardo Martinez; serusers at lists.iptel.org
>> Asunto: Re: [Serusers] Problem : Can SER process the reINVITE
>> messages properly?
>>
>>
>> Hm. This was a tricky one. I would like to ask a second
>> opinion from you
>> NAT gurus on my musings below. What is the most appropriate
>> response to
>> Ricardo's scenario? WARNING to others: This is getting fairly
>> technical on
>> NAT/SDP... ;-)
>>
>> The reINVITE from Asterisk has a valid IP address and a valid
>> (but new) SDP
>> media ip (C=IN IP4 200.0.0.7). nat=yes is correctly not
>> present in the
>> reINVITE from Asterisk (it is not NATed). Thus
>> use_media_proxy is correctly
>> not used in the reINVITE, i.e. client_nat_test("3") and test
>> on nat=yes will
>> not trigger under the has_totag if statement (loose route
>> processing):
>>
>> if (loose_route()) {
>>
>> if (has_totag() && (method=="INVITE" || method=="ACK")) {
>>
>> if (client_nat_test("3") || search("^Route:.*;nat=yes")) {
>> setflag(6);
>> use_media_proxy();
>> };
>> };
>>
>> route(1);
>> break;
>> };
>>
>> In the OK from the Linksys:
>> U 200.0.0.5:5060 -> 200.0.0.6:5060
>> SIP/2.0 200 OK.
>> To:
>> <sip:5555848114 at sipvoiss.desarrollo.redvoiss.net>;tag=64d7492d
>> b018b13ai0. From: "5565625858196"
>> <sip:5565625858196 at sipvoiss.desarrollo.redvoiss.net>;tag=as5d352c9a.
>> Call-ID:
>> 0848ef78297116742562204e2c04cbcb at sipvoiss.desarrollo.redvoiss.net.
>> CSeq: 104 INVITE.
>> Via: SIP/2.0/UDP 200.0.0.6:5060;branch=z9hG4bK518d870e.
>> Record-Route: <sip:200.0.0.5;ftag=as5d352c9a;lr=on>.
>> Contact: 5555848114 <sip:5555848114 at 200.0.0.4:46081>.
>> Server: Linksys/PAP2-2.0.10(LSb).
>> Content-Length: 237.
>> Content-Type: application/sdp.
>> .
>> v=0.
>> o=- 33068 33068 IN IP4 192.168.15.200.
>> s=-.
>> c=IN IP4 192.168.15.200.
>> t=0 0.
>> m=audio 16424 RTP/AVP 18 100 101.
>> a=rtpmap:18 G729/8000.
>> a=rtpmap:100 NSE/8000.
>> a=rtpmap:101 telephone-event/8000.
>> a=fmtp:101 0-15.
>> a=ptime:30.
>> a=sendrecv.
>>
>> ...you have 192.168.15.200, a private c= address in SDP, but
>> the Contact has
>> correctly been fixed (200.0.0.4:46081). So it seems the OK is
>> processed
>> correctly in onreply even though it does not show up in the
>> debug. Flags 6
>> and 7 are not set, so use_media_proxy is correctly not run.
>> The problem is
>> that flag 6 should have been set (the Linksys is NATed), but
>> as the reINVITE
>> is not processed using lookup("location") the flag will not
>> be picked up
>> from usrloc.
>> ----------------------------------------
>>
>> However, now that Asterisk in the reINVITE is requesting
>> another (valid) IP
>> as media destination, the question is: what is propor behavior?
>>
>> The most natural would be to add a lookup("location") after:
>> if (has_totag() && (method=="INVITE" || method=="ACK"))
>> and then add isflagset(6) to the or test:
>> if (isflagset(6) || client_nat_test("3") ||
>> search("^Route:.*;nat=yes")) {
>> setflag(6);
>> use_media_proxy();
>> };
>>
>> However, I'm not sure the lookup will work, because the R-URI
>> is likely to
>> be the direct address (5555848114 at 200.0.0.4:46081) and not
>> the registered
>> URI (@domain.com). It would be tempting to try to see if we
>> somehow could
>> make nat=yes set in the early INVITE. We would have to split the
>> record_route section in two. One to handle !="REGISTER &&
>> !="INVITE" with a
>> regular record_route() and wait until AFTER
>> lookup("location") (maybe in
>> route[1], the default handler) to add the following:
>> if(method=="INVITE")){
>> if(isflagset(6)) {
>> # INSERT YOUR IP ADDRESS HERE
>> record_route_preset("192.0.2.13:5060;nat=yes");
>> } else {
>> record_route();
>> }
>> }
>>
>> This would make sure that not only dialogs where caller is
>> nated, but also
>> where callee is nated, will be tagged as nated. This again
>> would cause
>> nat=yes to be set and rtp proxy forced, further flag 6 is
>> set, and thus the
>> OK also processed with use_media_proxy().
>>
>> BUT: Would this nat=yes cause any problems in other
>> scenarios??? I'm not
>> sure, but I don't think so. If that is correct, this is
>> maybe the right
>> solution.
>> ---------------------------------------
>> OTHER (SIMPLER?) SOLUTIONS:
>> ----------
>> Instead you could add ||client_nat_test("1") together with
>> isflagset 6 and 7
>> in your reply route:
>> if ((isflagset(6) || isflagset(7) || client_nat_test("1")) &&
>> (status=~"(180)|(183)|2[0-9][0-9]"))
>>
>> but it will not work because the reINVITE did not get
>> use_media_proxy().
>>
>> Or, you could instead add fix_nated_sdp("2"); in your onreply route:
>> if (client_nat_test("1")) {
>> fix_nated_contact();
>> fix_nated_sdp("2");
>> };
>> WARNING! You will have to add else in between this test and
>> the previous to
>> avoid messing up use_media_proxy().
>>
>> This will fix the SDP (c=IN IP4), but it will probably not
>> help, because the
>> port is still unknown. You could use "3" instead in
>> fix_nated_sdp, this
>> will add direction=active to the OK. However, another thread
>> stated that
>> Asterisk does not support direction=active. If it does, it
>> will probably
>> work and you get a non-proxied stream between Asterisk and
>> the Linksys.
>>
>> Or finally, the third option would be to add the (hopefully)
>> fixed IP in the
>> loose_route test:
>> if (src_ip==200.0.0.6 || client_nat_test("3") ||
>> search("^Route:.*;nat=yes")) {
>> setflag(6);
>> use_media_proxy();
>> };
>>
>> This would cause the OK automatically to get use_media_proxy.
>>
>> Ricardo, could you please test these various solutions and
>> see if they
>> really work or if (where...) I go wrong :-)
>> g-)
>>
>> Ricardo Martinez wrote:
>>> Hello Greger.
>>> Thanks for your answer on this topic. Now i'm attaching more debug
>>> information (the /var/log/messages from mediaproxy, the ngrep output
>>> and some xlog statements in the ser.cfg file) beside some
>> comments in
>>> the file reINVITE_debug_problem.txt.
>>>
>>>> - Is your session really set up initially (before the reINVITE)?
>>>> (mediaproxy reports 0/0/0 bytes)
>>>
>>> At least i have ringback tone. Then, when the call is answered i
>>> have an OK and a ACK message coming to my SER box, then inmediatly
>>> the reINVITE message arrives Asterisk box.
>>>
>>>
>>> For what i can see from the debug the "nat=yes" is never reached
>>> because the caller has a "valid ip" and therefore the first "if" in
>>> the statament
>>>
>>> if (method=="INVITE" && client_nat_test("3")) {
>>> # INSERT YOUR IP ADDRESS HERE
>>> record_route_preset("64.76.148.246:5060;nat=yes");
>>> xlog("L_INFO", "time [%Tf] RECORD ROUTE SECTION :
>>> invite & client_nat_test(3) TRUE ,record_route_preset [%rm]\n");
>>> } else if (method!="REGISTER") {
>>> xlog("L_INFO", "time [%Tf] RECORD ROUTE SECTION :
>>> record_route [%rm]\n");
>>> record_route();
>>> };
>>>
>>> from the RECORD ROUTE SECTION is FALSE.
>>>
>>> Also, i don't understand why the second OK (the one from the
>>> reINVITE) is not procesed in the ONREPLY ROUTE, or at least i don't
>>> see any statement from the "xlog" in the debug. Is this normal?
>>>
>>> Thanks.!
>>> Regards,
>>>
>>> Ricardo Martinez.-
>>>
>>>
>>>> -----Mensaje original-----
>>>> De: Greger V. Teigre [mailto:greger at teigre.com]
>>>> Enviado el: Lunes, 18 de Julio de 2005 2:45
>>>> Para: Ricardo Martinez; serusers at lists.iptel.org
>>>> Asunto: Re: [Serusers] Problem : Can SER process the reINVITE
>>>> messages properly?
>>>>
>>>>
>>>> Hi Ricardo,
>>>> Thanks for a detailed analysis. Some questions:
>>>> - Is your session really set up initially (before the reINVITE)?
>>>> (mediaproxy reports 0/0/0 bytes)
>>>> - You didn't show the ngrep trace. The script uses nat=yes in
>>>> the Route
>>>> header of the INVITE to detect a nat'ed client. Can you
>>>> verify that the
>>>> reINVITE has the nat=yes?
>>>> - You haven't showed the mediaproxy log (it will show the
>>>> callers reporting
>>>> in etc). That could help (default /var/log/messages)
>>>> - You can put a log statement in the loose_route section
>>>> after the test for
>>>> nat=yes to see if use_media_proxy was called
>>>>
>>>> g-)
>>>>
>>>> Ricardo Martinez wrote:
>>>>> Hello.
>>>>> I'm having problems trying to make SER, NAT'd endpoints
>>>> and reINVITE
>>>>> work together.
>>>>> I was using the "gw-pstn3.07.cfg" file from onsip.org to do some
>>>>> tests, and this is what i have. In one side i have an
>> Asterisk with
>>>>> an endpoint registered in it (let's call it A). In the
>> other side i
>>>>> have a PAP2 under NAT (let's call it B).
>>>>>
>>>>>
>>>>> A ---------- Asterisk ----------- SER ----------- B (NAT'd)
>>>>> 200.0.0.7 200.0.0.6 200.0.0.5
>>>>> 10.0.0.4
>>>>>
>>>>> When i make a call from "A" to "B" this is what i see (in terms of
>>>>> SDP). Looking from SER.
>>>>>
>>>>> A --------- Asterisk ------------ SER ------------ B (NAT'd)
>>>>> Public:
>>>>> 200.0.0.4
>>>>> 200.0.0.7 200.0.0.6 200.0.0.5
>>>> Inside:
>>>>> 10.0.0.1
>>>>>
>>>>> INVITE
>>>>> c:200.0.0.6:19996
>>>>> ------------------->
>>>>> INVITE
>>>>> c:200.0.0.5:35010
>>>>> ---------------->
>>>>>
>>>>>
>>>>> Caller Via Called Status
>>>>> Duration Codec Type Traffic
>>>>>
>>>> --------------------------------------------------------------
>>>> ------------
>>>>> 200.0.0.6:19996 - 200.0.0.5:35010 - ?.?.?.?:? inactive 0'04"
>>>>> Unknown Audio 0/0/0
>>>>>
>>>>> Total traffic: 0bps/0bps/0bps (in1/in2/out)
>>>>> Session count: 1
>>>>>
>>>>> So far is ok..........and the phone is answered
>>>>> OK
>>>>> c:10.0.0.1:16440
>>>>> <---------------- (the phone is
>>>>> answered)
>>>>> OK
>>>>> c:200.0.0.5:35010
>>>>> <---------------------
>>>>>
>>>>> reINVITE
>>>>> c:200.0.0.7:19996
>>>>> --------------------->
>>>>> reINVITE
>>>>> c:200.0.0.7:19996
>>>>> ---------------->
>>>>>
>>>>> OK
>>>>> c:10.0.0.1:16440
>>>>> <----------------
>>>>> OK
>>>>> c:10.0.0.1:16440
>>>>> <---------------------
>>>>>
>>>>> Finally according to the "session" information :
>>>>>
>>>>> Caller Via Called
>>>>> Status Duration Codec Type Traffic
>>>>>
>>>> --------------------------------------------------------------
>>>> --------------
>>>>> ----------
>>>>> 200.0.0.6:19996 - 200.0.0.5:35010 - 200.0.0.7:16420 inactive
>>>>> 0'26" G729 Audio 0/11.48k/11.48k
>>>>>
>>>>> Total traffic: 0bps/0bps/0bps (in1/in2/out)
>>>>> Session count: 1
>>>>> And the audio is only in one way. :(
>>>>>
>>>>> So. you can see the reINVITE message apparently is not being
>>>>> processed as a call to a NAT'd endpoint and therefore is not using
>>>>> the mediaproxy, you can see the second "OK" messsage has
>> the invalid
>>>>> IP from the NAT'd user is in his sdp information.
>>>>> As i said it before i am using the gw-pstn configuration
>>>> file from the
>>>>> onsip.org and as far as i can remember this configuration
>> can handle
>>>>> the reINVITE? isn't
>>>>> I'm also using the last version of the mediaproxy (1.3.1).
>>>>> Can someone tell me what i'm doing wrong?
>>>>>
>>>>> Hope someone could help me here.
>>>>> Thanks in advance.
>>>>> Regards...
>>>>>
>>>>> Ricardo Martinez.-
>>>>>
>>>>> _______________________________________________
>>>>> Serusers mailing list
>>>>> serusers at lists.iptel.org
>>>>> http://lists.iptel.org/mailman/listinfo/serusers
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