[Spce-user] No rewrite on T.38 INVITE

Tristan Delsol tdelsol at qfast.nl
Mon Aug 24 05:55:39 EDT 2015


I tried the 488 from LB, but if I do that I still get the same 404 not 
found. So I send the 488, the telco ACKs it and then sends a new INVITE 
without T.38 but the same happens with this INVITE, which is the 404 not 
found.

I have a trace of that one also if you want.

On 24-08-15 11:40, Daniel Grotti wrote:
> Hi,
> something wrong in your rewriting patch, cause proxy receives:
>
> Call from PSTN -
> R=sip:ngcp-lb at 87.239.101.193:5060;ngcpct=7369703a3132372e302e302e313a35303830
> ID=1183523204412000183319 at 192.168.111.25_b2b-1
>
>
> I would suggest to do not rewrite, but just reject the re-invite with
> 488 on LB if the RURI has that format.
>
>
> --
> Daniel Grotti
> VoIP Engineer
>
>
> Sipwise GmbH
> Europaring F15 | 2345 Brunn am Gebirge, Austria | www.sipwise.com
>
> On 08/24/2015 11:12 AM, Tristan Delsol wrote:
>> No problem. Attached.
>> And thanks for the help.
>>
>> Tristan
>>
>> On 24-08-15 11:09, Daniel Grotti wrote:
>>> would help to see LB an PROXY log.
>>>
>>>
>>> --
>>> Daniel Grotti
>>> VoIP Engineer
>>>
>>>
>>> Sipwise GmbH
>>> Europaring F15 | 2345 Brunn am Gebirge, Austria | www.sipwise.com
>>>
>>> On 08/24/2015 10:35 AM, Tristan Delsol wrote:
>>>> Daniel,
>>>>
>>>> I have no clue :)
>>>>
>>>> Here the re-invite before I rewrite the request-uri and the 404
>>>> response:
>>>> INVITE
>>>> sip:ngcp-lb;tgrp=9752;trunk-context=ipic.imscore.net at 87.239.101.193:5060;ngcpct=7369703a3132372e302e302e313a35303830
>>>>
>>>> SIP/2.0
>>>> Via: SIP/2.0/UDP
>>>> 139.156.126.49:5060;branch=z9hG4bKfofomd006o71lno6s1i0.1
>>>> Call-ID: 585966869312000201754 at 192.168.111.25_b2b-1
>>>> From:
>>>> <sip:+31306665648 at ims.imscore.net>;tag=SDemtl399-127.0.0.1alUtKGp-09752+1+a3000095+156d2c30
>>>>
>>>>
>>>> To:
>>>> <sip:+31756418049 at 192.168.111.25>;tag=3D534336-55D9A6A9000B9F71-7E3B2700
>>>> CSeq: 98894742 INVITE
>>>> Expires: 180
>>>> Contact: <sip:+31306665648 at 139.156.126.49:5060;transport=udp>
>>>> Min-SE: 90
>>>> Session-Expires: 7200;refresher=uac
>>>> Supported: replaces, path, 100rel, timer
>>>> Content-Length: 276
>>>> Allow: INVITE, BYE, REGISTER, ACK, OPTIONS, CANCEL, SUBSCRIBE, NOTIFY,
>>>> PRACK, INFO, REFER, UPDATE, PUBLISH, MESSAGE
>>>> Max-Forwards: 69
>>>> Content-Type: application/sdp
>>>> User-Agent: Alcatel-Lucent 5060 MGC-8 9.2.0.4.0.11
>>>> Route:
>>>> <sip:87.239.101.193;r2=on;lr=on;ftag=3D534336-55D9A6A9000B9F71-7E3B2700;ngcplb=yes>
>>>>
>>>>
>>>> Route:
>>>> <sip:127.0.0.1;r2=on;lr=on;ftag=3D534336-55D9A6A9000B9F71-7E3B2700;ngcplb=yes>
>>>>
>>>>
>>>>
>>>> v=0
>>>> o=- 3649316138 3649316139 IN IP4 139.156.126.49
>>>> s=-
>>>> c=IN IP4 139.156.126.49
>>>> t=0 0
>>>> m=image 23680 udptl t38
>>>> a=T38FaxVersion:0
>>>> a=T38MaxBitRate:14400
>>>> a=T38FaxRateManagement:transferredTCF
>>>> a=T38FaxMaxBuffer:72
>>>> a=T38FaxMaxDatagram:316
>>>> a=T38FaxUdpEC:t38UDPRedundancy
>>>>
>>>>
>>>> SIP/2.0 404 Not Found
>>>> Via: SIP/2.0/UDP
>>>> 139.156.126.49:5060;rport=5060;branch=z9hG4bKfofomd006o71lno6s1i0.1
>>>> Call-ID: 585966869312000201754 at 192.168.111.25_b2b-1
>>>> From:
>>>> <sip:+31306665648 at ims.imscore.net>;tag=SDemtl399-127.0.0.1alUtKGp-09752+1+a3000095+156d2c30
>>>>
>>>>
>>>> To:
>>>> <sip:+31756418049 at 192.168.111.25>;tag=3D534336-55D9A6A9000B9F71-7E3B2700
>>>> CSeq: 98894742 INVITE
>>>> Server: Sipwise NGCP Proxy 3.X
>>>> Content-Length: 0
>>>>
>>>> Tristan
>>>>
>>>>
>>>> On 24-08-15 09:08, Daniel Grotti wrote:
>>>>> Hi,
>>>>> how can you receive a 404 on a re-invite ?
>>>>> Does the re-invite have the From-tag and To-tag ?
>>>>>
>>>>>
>>>>> --
>>>>> Daniel Grotti
>>>>> VoIP Engineer
>>>>>
>>>>>
>>>>> Sipwise GmbH
>>>>> Europaring F15 | 2345 Brunn am Gebirge, Austria | www.sipwise.com
>>>>>
>>>>> On 08/24/2015 12:23 AM, Tristan Delsol wrote:
>>>>>> Checked a lot of things but I'm still getting a 404 not found from
>>>>>> spce.
>>>>>> I managed to change the request-uri from
>>>>>> sip:ngcp-lb;tgrp=9752;trunk-context=ipic.imscore.net at 87.239.101.193:5060;ngcpct=7369703a3132372e302e302e313a35303830
>>>>>>
>>>>>>
>>>>>> to
>>>>>> sip:ngcp-lb at 87.239.101.193:5060;ngcpct=7369703a3132372e302e302e313a35303830,
>>>>>>
>>>>>>
>>>>>> but I'm still getting a 404 not found.
>>>>>> Shouldn't this work?
>>>>>> I mean the spce is sending this as Contact.
>>>>>>
>>>>>> Tristan
>>>>>>
>>>>>> On 2015-08-21 14:25, Daniel Grotti wrote:
>>>>>>> Hi,
>>>>>>> yes something like:
>>>>>>>
>>>>>>> if(is_method("INVITE") && uri =~ "^sip:ngcp-lb;tgrp.+@")
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Daniel Grotti
>>>>>>> VoIP Engineer
>>>>>>>
>>>>>>>
>>>>>>> Sipwise GmbH
>>>>>>> Europaring F15 | 2345 Brunn am Gebirge, Austria | www.sipwise.com
>>>>>>>
>>>>>>> On 08/20/2015 07:44 PM, Tristan Delsol wrote:
>>>>>>>> Hi Daniel,
>>>>>>>>
>>>>>>>> The only problem is actually that the telco sends this weird invite
>>>>>>>> with
>>>>>>>> the following request-uri:
>>>>>>>> sip:ngcp-lb;tgrp=9752;trunk-context=ipic.imscore.net at 87.239.101.193:5060;ngcpct=7369703a3132372e302e302e313a35303830
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> If I could maybe rewrite this to remove the
>>>>>>>> ";tgrp=9752;trunk-context=ipic.imscore.net" or send a 488 then I
>>>>>>>> should
>>>>>>>> be good.
>>>>>>>>
>>>>>>>> Could I add something to
>>>>>>>> /etc/ngcp-config/templates/etc/kamailio/proxy/proxy.cfg.customtt.tt2
>>>>>>>> like
>>>>>>>> if(is_method("INVITE") &&
>>>>>>>> search("tgrp=9752;trunk-context=ipic.imscore.net"))
>>>>>>>> {
>>>>>>>>       sl_send_reply("488", "Not Acceptable Here");
>>>>>>>>       exit;
>>>>>>>> }
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Tristan
>>>>>>>>
>>>>>>>> On 2015-08-20 16:15, Tristan Delsol wrote:
>>>>>>>>> The reason is that the interconnect with our telco is tripping over
>>>>>>>>> our contact-header of ngcplb@<ip> only with T.38, because of the
>>>>>>>>> re-invite.
>>>>>>>>> They hide behind the fact that they have a spec for the
>>>>>>>>> interconnect
>>>>>>>>> that only wants phonenumber@<ip>or<dns> in the contact-header.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 20-08-15 16:05, Daniel Grotti wrote:
>>>>>>>>>> Hi,
>>>>>>>>>> any reason for that ?
>>>>>>>>>> The callee should reply 488, not the server.
>>>>>>>>>> Anyway, I remember some old threasd about that:
>>>>>>>>>> https://lists.sipwise.com/pipermail/spce-user/2014-June/006788.html
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Maybe this could help.
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Daniel Grotti
>>>>>>>>>> VoIP Engineer
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Sipwise GmbH
>>>>>>>>>> Europaring F15 | 2345 Brunn am Gebirge, Austria | www.sipwise.com
>>>>>>>>>>
>>>>>>>>>> On 08/20/2015 03:41 PM, Tristan Delsol wrote:
>>>>>>>>>>> Back again on this :)
>>>>>>>>>>>
>>>>>>>>>>> One more thing. Would it be possible to disable T.38 support
>>>>>>>>>>> somehow. So
>>>>>>>>>>> that if the RE-INVITE comes in that we send back a 488?
>>>>>>>>>>> Or maybe I can set it up for certain subscriber numbers?
>>>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>> Tristan
>>>>>>>>>>>
>>>>>>>>>>> On 17-08-15 17:01, Tristan Delsol wrote:
>>>>>>>>>>>> Thanks for the info. I will experiment with that to see if it
>>>>>>>>>>>> works.
>>>>>>>>>>>> Then I will check if we would really want that or not.
>>>>>>>>>>>>
>>>>>>>>>>>> Tristan
>>>>>>>>>>>>
>>>>>>>>>>>> On 17-08-15 16:58, Andrew Pogrebennyk wrote:
>>>>>>>>>>>>> On 08/17/2015 03:39 PM, Tristan Delsol wrote:
>>>>>>>>>>>>>> They state that they don't support that format for the contact
>>>>>>>>>>>>>> header.
>>>>>>>>>>>>>> They have it in the specs for the interconnect that the
>>>>>>>>>>>>>> contact
>>>>>>>>>>>>>> header
>>>>>>>>>>>>>> can only contain the following:
>>>>>>>>>>>>>> sip:+«ISN»@«ip-address/URL»:«port» with optional
>>>>>>>>>>>>>> user=”phone”, so
>>>>>>>>>>>>>> for
>>>>>>>>>>>>>> example sip:+31703434343 at domain.net:5060;user=”phone”.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Where
>>>>>>>>>>>>>> ISN: International Subscriber Number
>>>>>>>>>>>>>> port: UDP portnumber;
>>>>>>>>>>>>>> URL: Uniform Resource Locator: domain name;
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Is it possible I can adjust the contact header for this
>>>>>>>>>>>>>> kind of
>>>>>>>>>>>>>> request
>>>>>>>>>>>>>> to keep the format as needed?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Unfortunately this is not something you can easily achieve,
>>>>>>>>>>>>> but if
>>>>>>>>>>>>> you
>>>>>>>>>>>>> have some understanding of kamailio config scripts you can
>>>>>>>>>>>>> try to
>>>>>>>>>>>>> modify
>>>>>>>>>>>>> /etc/ngcp-config/templates/etc/kamailio/lb/kamailio.cfg.tt2
>>>>>>>>>>>>> and disable the Contact masking completely, e.g. comment out
>>>>>>>>>>>>> all
>>>>>>>>>>>>> calls
>>>>>>>>>>>>> of ROUTE_MASK_CONTACT and ROUTE_UNMASK_CONTACT as a starting
>>>>>>>>>>>>> point.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Then each side will receive the internal IP of b2b as Contact:
>>>>>>>>>>>>> sip:127.0.0.1:5080, which exposes your topology a bit to
>>>>>>>>>>>>> outside
>>>>>>>>>>>>> but
>>>>>>>>>>>>> still doesn't break the protocol. But we are not sending the
>>>>>>>>>>>>> number part
>>>>>>>>>>>>> which might be a problem for them (they didn't say that the
>>>>>>>>>>>>> number
>>>>>>>>>>>>> part
>>>>>>>>>>>>> is optional). Sorry I can't help you out more at this time.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>> Andrew
>>>>>>>>>>>>>
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