[SR-Users] Kamailio parse failed message

[Hai Bui Duc Ha]

Hi Daniel,

It didn't fixed, I just send you more information about the capturing on
both client and server side.

Regards,
Hai Bui

On Tue, Feb 7, 2017 at 1:40 PM, Daniel-Constantin Mierla <miconda at gmail.com>
wrote:

> Hello,
>
> with TCP there is no MTU. In the previous pcap you sent there was a wrong
> Content-Length value. Was that fixed?
>
> Cheers,
> Daniel
>
> On 06/02/2017 12:24, Hai Bui Duc Ha wrote:
>
> Hi Daniel,
>
> I send you the pcap files on both client and server side.
> Analyse this files, I see the packet can not "reassemble"  INVITE message
> at server side:
> - At client.pcapng, it can detect 6 and 7th packets are one.
> - But on server.pcap, it can not "reassemble" 18 and 21st packets.
>
> I just explain as my understand. If you have any information, please ask
> me.
> I think the problem relate the MTU - fragmentation. But I'm not sure about
> this.
> Thank you for support !
>
> Regards,
> Hai Bui
>
> On Sun, Jan 22, 2017 at 4:33 PM, Hai Bui Duc Ha <hai.bui at htklabs.com>
> wrote:
>
>> Hi Daniel,
>>
>> Thank for your advice.
>> I will capture and analyze the call log on both client and kamailio to
>> check the packet size.
>>
>> Regards,
>> Hai Bui
>>
>>
>> On Fri, Jan 20, 2017 at 3:38 PM, Daniel-Constantin Mierla <
>> miconda at gmail.com> wrote:
>>
>>>
>>>
>>> On 19/01/2017 22:56, Daniel-Constantin Mierla wrote:
>>>
>>> Hello,
>>>
>>> On 19/01/2017 10:48, Hai Bui Duc Ha wrote:
>>>
>>> Hi Daniel,
>>>
>>> Thank you for reply.
>>>
>>> On Tue, Jan 17, 2017 at 6:05 PM, Daniel-Constantin Mierla <
>>> miconda at gmail.com> wrote:
>>>
>>>> Hello,
>>>>
>>>> apparently I missed the follow ups on this discussion, dragged in by
>>>> other topics on mailing list.
>>>>
>>> Can you get the pcap with all the traffic taken on kamailio server for
>>>> the call (from initial invite to the end of the call)?
>>>>
>>> I send you the pcap at enclosed file. You can see the packet *No.5 *,
>>> it missing SIP message body:
>>> *            Media Attribute (a): rtpmap:8 PCMA/8000*
>>> *            Media Attribute (a): rtpmap:101 telephone-event/8000*
>>> *            Media Attribute (a): fmtp:101 0-16*
>>>
>>>> I expect that content length is mismatching or there is a '\0' inside
>>>> the sdp.
>>>>
>>> Can you explain me more about this ?
>>>
>>> TCP is a stream protocol, meaning that the application (kamailio) need
>>> to read and parse to figure out the end of a SIP message. The state machine
>>> as per RFC requires the application to read and identify the Content-Length
>>> header, take its value, read until the end of headers is found (an empty
>>> line) and from there on read as much as the value of Content-Length to get
>>> the body and consider the end of message there.
>>>
>>> If the sending application puts a lower value in the Content-Length than
>>> the number of chars in the body, the rest remains in the buffer and the
>>> receiving application (kamailio) attempts to parse a new SIP message.
>>>
>>> The other thing I was thinking of was the presence of '\0' which marks
>>> the end of string in C.
>>>
>>> I will look at the pcap very soon and see what I find there.
>>>
>>> The problem is the value of Content-Lenght set by the client -- it is
>>> set only to the size that it is view as part of the invite. A bit later the
>>> client sends more sdp, but exceeding the size sent in C-L header. That part
>>> of SDP remains as garbage.
>>>
>>> So there is a bug in client app.
>>>
>>> Cheers,
>>> Daniel
>>>
>>> --
>>> Daniel-Constantin Mierlawww.twitter.com/miconda -- www.linkedin.com/in/miconda
>>> Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com
>>>
>>>
>>
>>
>> --
>> Hai Bui
>> VoIP engineer, Cvoice team, HTK-HCM Office
>> Mobile: +84-165-618-9876
>>
>
>
>
> --
> Hai Bui
> VoIP engineer, Cvoice team, HTK-HCM Office
> Mobile: +84-165-618-9876
>
>
> --
> Daniel-Constantin Mierlawww.twitter.com/miconda -- www.linkedin.com/in/miconda
>
> Kamailio Advanced Training - Mar 6-8 (Europe) and Mar 20-22 (USA) - www.asipto.com
> Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com
>
>


-- 
Hai Bui
VoIP engineer, Cvoice team, HTK-HCM Office
Mobile: +84-165-618-9876
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