Subject: [Tsvwg] sctp abort during high traffic load exchange

From: "arif khan" <[email-masked]>
Date: Wed, 6 Jun 2007 22:50:17 +0100

hi,

we have around 135 multihomed assoc. and all are exchanging traffic (traffic
rate is high) in the mean time server sctp endpoints send abort to the
client sctp.
ethereal dump ecode of cause 4.

how could we check reason of abort?
could you suggest how we can verify it over single assoc with changing the
rto,rtt,max path retrans or hb interval value.

tia
-arif

---

From: Michael Tuexen <[email-masked]>
Date: Thu, 7 Jun 2007 00:27:22 +0200

Hi Arif,

a look at the source code of the SCTP dissector tells me

#define OUT_OF_RESOURCE                            0x04

so I guess you are running out of resources. Which SCTP implementation
are you using?

Best regards
Michael

On Jun 6, 2007, at 11:50 PM, arif khan wrote:

> hi,
>
> we have around 135 multihomed assoc. and all are exchanging traffic  
> (traffic rate is high) in the mean time server sctp endpoints send  
> abort to the client sctp.
> could you suggest how we can verify it over single assoc with  
> changing the rto,rtt,max path retrans or hb interval value.
>
> tia
> -arif

---

From: "Nemana, Satya Prasad (STSD)" <[email-masked]>
Date: Thu, 7 Jun 2007 10:57:47 +0530

Hi Arif

I guess there are lot of considerations for this. It will be better if
you can elaborate on the following

1.	When you say high traffic rate, what do you mean?
2.	Are you observing the CPU usage on the system?

You may be out of resources.

3.	Ethereal GUI can take significant CPU almost 25%.. try the same
without the ethereal GUI

Even if you are using Command line capture also. Since it is "high
traffic" the logging may take a lot of CPU

Also check you don't have traces enabled on any of your programs. :-)

4.	Every system defines its own restrictions for the max number of
associations . please check your system's considerations.

Hope this initial tips help.

Regards,

Satya Prasad

________________________________

From: arif khan [mailto:[email-masked]] 
Sent: Thursday, June 07, 2007 3:20 AM
To: [email-masked]
Subject: [Tsvwg] sctp abort during high traffic load exchange

hi,

we have around 135 multihomed assoc. and all are exchanging traffic
(traffic rate is high) in the mean time server sctp endpoints send abort
to the client sctp.

could you suggest how we can verify it over single assoc with changing
the rto,rtt,max path retrans or hb interval value.

tia

-arif

---

From: Alan Jay Weiner <[email-masked]>
Date: Thu, 07 Jun 2007 10:18:55 -0400

Error code 4 is "out of resources"

I'd presume that it's caused by whatever has been sent to that endpoint just
prior to the abort, or shortly before.  Looking at the traces, does that give
you any clue as to the cause of the abort?
Is the T bit set?  if not, are you trying to set up another association?

- Al Weiner -
(not an SCTP guru, but getting there...   :)

-- original message --

>rto,rtt,max path retrans or hb interval value.

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