Compared performance of different file transfer protocols over latency

Internet is providing more and more bandwidth to transfer files and files are bigger and bigger. One thing is not changing, it is latency as distance still the same over the time. When a protocol requires acknowledgment between blocks of transfer this latency is limiting the throughput like explained in this post.

The throughput is really different depending on the protocol in use to transfer the file. As I did not found something giving a lot of data to compare the existing protocol, i’ll try to get figures myself and detail here.

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My Clermont’ech talk about MQTT

My last post was about a demonstration of what you can do in 5 minutes with MQTT. This video was part of a global MQTT presentation I’ve done for Clermont’ech APIHours.

Here is a full version of this talk in English. For French reader, the video of the talk in French will come soon as soon as Clermont’ech team will finalize it.

Enjoy !


Slide are here :

MQTT compared to HTML for its network saving

I’m interested by MQTT for two reason, the first one is related to its services and QoS management, the second by its network efficiency because I’d like to use it over a 3G communication system with a small and low cost plan.

MQTT promise is to be network efficient but, i’d like to see it with my eyes, so I’ll try to give you some measures I’ve done to confirm it. My fear is that keep alive communication for subscriber costs could be high and request some software adaptations.

See full article to get details and eventually reproduce

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Raspberry PI – wan emulation

PIWan project : Here is a new, quick & dirty project to be done with a raspberry PI : At work we currently have to simulate our application for a worldwide usage. We have really great tools for that but they need expertise and specific campaigns. The purpose of this document is to describe a RPI based solution with two Ethernet cards and some clever command lines to simulate a wan network for developers. The advantage of this solution will be to cost less than 100euros and will be easy to use with the right documentation.

See next pages for implementation details:

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BeagleBone Black – configure NTP client

The BeagleBone black do not have Real Time Clock and as a consequence each time you reboot, you’re back at time 0. To get it updated to the local hour, you can configure NTP client (if connected to network) using the following commands:

root@beaglebone:~# opkg update
root@beaglebone:~# opkg install ntp ntpdate
root@beaglebone:~# mv /etc/localtime /etc/localtime.old
root@beaglebone:~# ln -s /usr/share/zoneinfo/Europe/Paris /etc/localtime
root@beaglebone:~# killall -KILL ntpd
root@beaglebone:~# ntpdate
root@beaglebone:~# /etc/init.d/ntpd start
root@beaglebone:~# date
Sun Jun  2 17:41:10 CEST 2013

Configurer la DMZ sur une BBox Sensation

Un petit article, plus pour le troll qu’autre chose … Depuis que je suis passé à la fibre Bouygues je dévouvre la bbox sensation et son niveau de bug jamais atteind par ce type d’équipement … Aujourd’hui après un reset factory default (seul moyen pour réactivé le Wifi une fois désactivé), j’ai souhaité configuré la DMZ pour ne pas avoir à recommencer la configuration NAT un peu plus longue.

J’avais précédemment rencontré des problèmes que j’avais attribué au fait d’avoir changer l’adresse IP par défaut. Il n’en est en fait rien : la fonctionnalité ne mache simplement pas, tout du moins sur firefox ou safari. Le Javascrit executé ne savant visiblement pas lire le champ prérempli contenant l’IP cible. Ainsi un joli message vous indique que tous les champs ne sont pas rempli et la validation est impossible.

J’en suis donc passé par FireBug : la methode est simple (enfin si l’on veut)

1. Aller sur la page DMZ, se loguer en lançant firefox et activant l’onglet JS

2. Recherche la fonction OnSubmit()

function onSubmit()
   if (element('displayIP').style.display == '') { 
      var ip = '';
   } else { 
      var ip = checkInput(false);
      if (ip)

3. Mettre un point d’arret dessus
4. Exécuter jusqu’à la ligne if(ip)
5. Modifier la variable IP pour lui mettre l’IP cible ex : “”
6. Continuer l’exécution

Après l’exécution de la fonction, si vous revenez sur l’onglet DMZ, vous verez que celle-ci est activée.

Après, si ca ne marche pas, il ne faut peut etre pas jeter la pierre à Bouygues … ils ont peut etre testé avec IE6, qui sait !



PirateBox upgrade to Forban

I’m looking to upgrade my two pirate box to test the mesh network forban between the two. Apparently, this will slow down the device as the TP Link small devices are not so powerful, but i like the idea to be able to create mesh network between piratebox. In my point of view it is the right way to make this project real.

I actually have my two piratebox configured in version 0.5, i’ll firstly update them to the latest version, then add the Forban tool following Matthias’s materials.

I’ll upgrade my TP Link Mr3020 and TP Link MR3040.

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Promiscious mode wifi capture on iMac with Atheros 5416

Sound a old hardware, but as it is not the first time I have issue to dump (tcpdump or wireshark) wifi connection on promiscuous mode, I prefer to write it once of all … It is not working !!!

If any of you have a solution to make it works, I’ll be happy to update this post. For the others, I expect you will loss less time searching and trying.

I’ve try to change the rights on the /dev/bfp* devices

I’ve try to use tcpdump -i en1 host xx.xx.xx.xx instead of wireshark

And at the end, I finally just got the broadcast traffic and the local traffic.