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Hi Sumathi,

we will make sure that this will work in the next release. It
is definitly a bug in the sctplib, not in the socketapilib.
Thank you very much for the detailed report.

Best regards
Michael

Michael Tuexen Tel.: +49 89 722 47210
Siemens AG Fax: +49 89 722 48212
ICN CP SE C 7 e-mail:
Michael.Tuexen AT siemens.com

> -----Original Message-----
> From: Elangovan, Sumathi
> [mailto:Sumathi.Elangovan AT thalesgroup.com]
> Sent: Friday, February 14, 2003 11:53 AM
> To: 'Michael Tüxen'; 'Andreas Jungmaier';
> discussion AT sctp.de
> Cc: Thomson, Iain
> Subject: [SCTP-Discussion] Packet dropped!!!
>
>
> Hi!
> I am using socketapi-1.0.1 using version sctplib-1.0.0-pre19
> (socketapi via
> the socketapilib). I want to test the SCTP behaviour when a packet is
> dropped. This is achieved by introducing noise of BER
> 1x10-7. I have listed
> the various scenarios that it was tested below:
>
> 1) 8k message size of 1M of data transfer with delay of
> 250S, noise 1x10-7
> Results show that
> * The transmitter is not able to recover when a packet is dropped
> * Abort occurs when it cannot recover
> * Which in turn does not retransmit the lost packet
>
> Question: Why isnt the transmitter not able to recover?
>
> 2) 1K message size of 1M data transfer with delay of
> 250S,noise 1x10-7,
> * Transmitter is able to recover
> * and ensure Complete transmission of data
> * No retransmission of lost packet
> * Forward TSN occurs
>
> Question: Why there is no retransmission of lost packet?
>
> 3) Unordered delivery is set,1K message size of 1M data with delay of
> 250S,noise 1x10-7,
> * Forward TSN occurs
> * Even when the a_rwnd does not decrease its size as data is
> transferred
> * No retransmission of lost packet
> * Ensures complete transmission of data
>
> Question: Why does Forward-TSN occur and there is no
> retransmission of data?
>
> 4) Unordered delivery,1k message size of 126K data tranafer with NO
> DELAY,noise 1x10-7
> * Forward TSN occurs
> * a_rwnd stays the same i.e does not decrease
> * No retransmission of lost packet.
>
> Question: Why there is no retransmission of lost packet even
> with no delay
>
> Any help would be appreciated. I realise that that for the first two
> questions you gave me some solutions but why even with
> unordered delivery
> set its not able to retransmit the lost packet? Is
> retransmission of lost
> packets not implemented with the present release? If yes,
> could you please
> let me know when the next version will be released. Thank you.
> I would also like to extend my help for any further debugging
> that you might
> require.Thanks for all your help!!
>
>
> Regards
> Sumathi Elangovan
>
> Sumathi Elangovan
> Design Engineer
> Thales Research and Technology(UK) Ltd
> Reading
> Tel: 0118 923 8272
> Email :
> Sumathi.Elangovan AT thalesgroup.com
>
>
> _______________________________________________
> discussion mailing list
> discussion AT sctp.de
> http://www.sctp.de/mailman/listinfo/discussion
>

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• [SCTP-Discussion] Packet dropped!!!, Elangovan, Sumathi , 02/14/2003
  • Re: [SCTP-Discussion] Packet dropped!!!, Andreas Jungmaier, 02/18/2003
  • <Possible follow-up(s)>
  • RE: [SCTP-Discussion] Packet dropped!!!, Tuexen Michael, 02/14/2003
    • RE: [SCTP-Discussion] Packet dropped!!!, Torbjörn Andersson, 02/14/2003
  • RE: [SCTP-Discussion] Packet dropped!!!, Tuexen Michael, 02/14/2003

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