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

Tristan Delsol tdelsol at qfast.nl
Mon Aug 24 04:35:00 EDT 2015


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
>>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> Spce-user mailing list
>>>>>>>> Spce-user at lists.sipwise.com
>>>>>>>> https://lists.sipwise.com/listinfo/spce-user
>>>>>>> _______________________________________________
>>>>>>> Spce-user mailing list
>>>>>>> Spce-user at lists.sipwise.com
>>>>>>> https://lists.sipwise.com/listinfo/spce-user
>>>>>> _______________________________________________
>>>>>> Spce-user mailing list
>>>>>> Spce-user at lists.sipwise.com
>>>>>> https://lists.sipwise.com/listinfo/spce-user
>>>>>>
>>>>> _______________________________________________
>>>>> Spce-user mailing list
>>>>> Spce-user at lists.sipwise.com
>>>>> https://lists.sipwise.com/listinfo/spce-user
>>>> _______________________________________________
>>>> Spce-user mailing list
>>>> Spce-user at lists.sipwise.com
>>>> https://lists.sipwise.com/listinfo/spce-user
>>> _______________________________________________
>>> Spce-user mailing list
>>> Spce-user at lists.sipwise.com
>>> https://lists.sipwise.com/listinfo/spce-user



More information about the Spce-user mailing list