January/February 2018 issue of acmqueue

The January/February issue of acmqueue is out now


  Download PDF version of this article PDF

ITEM not available


Originally published in Queue vol. 10, no. 6
see this item in the ACM Digital Library



Yonatan Sompolinsky, Aviv Zohar - Bitcoin's Underlying Incentives
The unseen economic forces that govern the Bitcoin protocol

Antony Alappatt - Network Applications Are Interactive
The network era requires new models, with interactions instead of algorithms.

Jacob Loveless - Cache Me If You Can
Building a decentralized web-delivery model

Theo Schlossnagle - Time, but Faster
A computing adventure about time through the looking glass


(newest first)

Gopal Agrawal | Fri, 26 Apr 2013 14:17:04 UTC

@Sriram: ... unless its neighbor discovers the new hop? .. That is correct. Openflow switches by themselves will not send LLDP packets, but a controller can force a switch to flood LLDP packets out of all its ports. If the newly joined neighboring node is also openflow enabled, it would report that LLDP packet to the controller (in which case the controller discovers the new OF switch and the port/link on which the LLDP packet arrived). If the newly joined node is not OF enabled (i.e., a legacy switch or router), it will typically flood the LLDP packet and other (possibly multiple) OF switches will receive that LLDP packet and send it to controller; which can then decipher that there is a legacy node in between (though not sure what happens if there is a chain of legacy nodes in between two OF switches).

Sriram | Sun, 24 Mar 2013 15:17:21 UTC

What about the dynamic nature of network? new nodes(including routers) are added and removed from the network every second. How can the central point of intelligence(controller) know bout the changes in the network, in case of nodes not reporting to the center, when attaching and detaching itself to the network, unless its neighbor discovers the new hop?

Kevin | Wed, 22 Aug 2012 22:44:17 UTC

This is a nice, completely uncritical examination of what's going on with OpenFlow, but I think that the repeated inaccurate comparisons to smartphone apps, and to Apple, weakens the article. I was running a variety of apps on my Treo smartphone long before Apple started work on the iPhone, and my provider had nothing to say about it. How am I going to believe that you got the facts about OpenFlow right if I'm pretty sure that you screwed up smartphone history?

robin mathur | Fri, 13 Jul 2012 06:04:38 UTC

Respected Sir,

your idea is too good. the thing is if so many game servers on openflow will run on same instance , then Will there be a need to prioritize the list ? How can you do that ?

Regards Robin Mathur Deptt. of CSE LPU-India

troy | Wed, 11 Jul 2012 21:42:36 UTC

interesting idea http://www.silentcrash.com/2011/11/how-to-get-a-remote-server-ip-and-dns-settings-via-powershell/

Leave this field empty

Post a Comment:

© 2018 ACM, Inc. All Rights Reserved.