[h323plus] Valid sessionID in OpenLogicalChannel command

Igor Pavlov pavlov.ig at gmail.com
Mon Dec 28 09:24:20 EST 2009


Simon

I can see following sequence of packets with sniffer:

me -> T1000 : masterSlaveDetermination : terminalType 50
T1000 -> me : masterSlaveDetermination : terminalType 50
me -> T1000 : masterSlaveDeterminationAck : descision slave(1)
T1000 -> me : masterSlaveDeterminationAck : descision master(0)

Am I understand you right that T1000 says that he is master, however don't
discharge master's obligations correct ?

May be Assert should work only in debug? But in release in this case
h323plus should just reject such RTP session (with incorrect sessionID) ?

Igor

28 декабря 2009 г. 16:47 пользователь Simon Horne
<s.horne at packetizer.com>написал:

>  Igor
>
> The problem you are having with the Tandberg T1000 is a tandberg bug. The
> endpoint cannot properly renegotiate the OLC on a master/slave conflict. The
> H323plus end advises the T1000 that it is master however the T1000 ignores
> it causing the conflict. Tandberg may have a firmware update to correct the
> problem.
>
> Simon
>
>  ------------------------------
> *From:* Igor Pavlov [mailto:pavlov.ig at gmail.com]
> *Sent:* Monday, 28 December 2009 11:07 PM
>
> *To:* Simon Horne
> *Cc:* h323plus at lists.packetizer.com
> *Subject:* Re: [h323plus] Valid sessionID in OpenLogicalChannel command
>
> About H.264 plugin - actualy I have 3rd party static library for H.264
> encoding/decoding and use H264 plugin as wrapper to connect library to
> h323plus. I don't think anyone has interest of half working plugin without
> static library...
>
> 28 декабря 2009 г. 15:57 пользователь Simon Horne <s.horne at packetizer.com>написал:
>
>>  Igor
>>
>> The problem is caused by an master/slave conflict when first opening the
>> audio channel which results in the OLC being rejected. The correct
>> process is to renegotiate the OLC. It appears that the T1000 cannot properly
>> renegotiate the OLC and incorrectly allocates an invalid sessionID of 0
>> which causes the assert and behavior you highlighted.
>>
>> I also see you are using a modified and working H.264 plugin and have
>> decided not to contribute any of that work back to the project. This is a
>> pity.
>>
>> Simon
>>
>>
>>  ------------------------------
>> *From:* Igor Pavlov [mailto:pavlov.ig at gmail.com]
>> *Sent:* Monday, 28 December 2009 9:46 PM
>> *To:* Simon Horne
>> *Cc:* h323plus at lists.packetizer.com
>> *Subject:* Re: [h323plus] Valid sessionID in OpenLogicalChannel command
>>
>>   Sending log.
>> T1000 in most cases after Reject sends OLC with sessionID=0, and in less
>> cases send OLC with sessionID from 32 up to 53 (increase 1 after each
>> reject).
>>
>>
>> 2009/12/28 Simon Horne <s.horne at packetizer.com>
>>
>>>  Igor
>>>
>>> Session ID should never be zero. This is clearly an error coming from the
>>> T1000 unit.
>>>
>>> Can you post a level 6 trace showing the condition the T1000 sends an OLC
>>> with sessionID = 0
>>>
>>> Simon
>>>
>>>  ------------------------------
>>> *From:* h323plus-bounces at lists.packetizer.com [mailto:
>>> h323plus-bounces at lists.packetizer.com] *On Behalf Of *Igor Pavlov
>>> *Sent:* Monday, 28 December 2009 8:25 PM
>>> *To:* h323plus at lists.packetizer.com
>>> *Subject:* [h323plus] Valid sessionID in OpenLogicalChannel command
>>>
>>>   Hi.
>>>
>>> I have problem when I reject OpenLogicalChannel (audio) while
>>> communicating with Tandberg T1000.
>>> In most cases Tandberg send me OpenLogicalChannel again with sessionID=0
>>> so my application falls in assertion
>>> in file rtp.cxx line 760 :
>>> PAssert(id > 0 && id < 256, PInvalidParameter);
>>>
>>> I could not find valid value range for sessionID, but I don't like when
>>> application crashes in this case :(
>>> What can I do in this situation?
>>>
>>>
>>> Igor Pavlov
>>>
>>
>>
>>
>> --
>> Игорь Павлов
>>
>
>
>
> --
> Игорь Павлов
>



-- 
Игорь Павлов
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