From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: SCTP research inquiry Date: Wed, 03 Sep 2014 16:44:07 -0400 Message-ID: <54077D97.9060608@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: Kostantinos Katsaros , netdev Return-path: Received: from mail-qg0-f48.google.com ([209.85.192.48]:45948 "EHLO mail-qg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754017AbaICUoL (ORCPT ); Wed, 3 Sep 2014 16:44:11 -0400 Received: by mail-qg0-f48.google.com with SMTP id z107so8801033qgd.7 for ; Wed, 03 Sep 2014 13:44:10 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 09/03/2014 01:07 PM, Kostantinos Katsaros wrote: > Dear NetDev list, > > I am a researcher from Univ. of Surrey. I know that this list is > mainly for developers of linux-kernel but I want to ask for some help > to understand the SCTP implementation and pointers to some aspects. > > What I would actually like to do, is to modify the default SCTP > operation with respect to primary/secondary interface selection and > analyse it in simulations with NS-3. However, I haven't found an API > or some other help and I was advised to contact this list. I know that > NS-3 is capable of using linux-kernel implementations through the use > of DCE, but my issue here is in the SCTP implementation. > > > There a few questions I have in a basic scenario with two nodes > connected via 2 interfaces. Are you looking for user-space API that provide the information you need? The reason I ask is that all I've seen of dce requires you to have an posix-like application to run on top of the protocol you want to use. I don't know if DCE allows you directly call linux kernel functions. Based on the above answer, I can point you more resources. -vlad > > - How can I dynamically select which of the two interfaces is primary? > Which method is responsible or should be called to switch? > > - I guess that SCTP has some variable holding the estimated RTT on > each path (also used for calculating RTO). Is this accessible and how? > I would like to use this as a triggering mechanism to the switch > method above. In principle select the path with the minimum RTT. > > - In a similar way of TCP Westwood (Plus), I would like to estimate > the available bandwidth and use this as trigger. > > - Finally, I want to monitor the ratio (packets or bytes sent) on each > of the available paths. How can I implement such mechanism? Do I have > to implement a 'sniffer'? > > > I would appreciate any help, pointers, code snippets. > > > Regards, > > Kostas > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >