reading on "Chord"

Summary: This paper presents "Chord" using consistent hashing which is designed to let nodes enter and leave the network with minimal disruption. The chord protocol is described clearly in the paper in which some important features like simplicity, provable correctness and provable performance are also discussed. The authors believe that Chord will become a valuable component for peer-to-peer systems.

Background: consistent hashing

Discussion:

1, i feel a little bit lost about Chord's Scalable Key Location. How Chord makes it?

2, in another paper the authors talked about DHT, but in Chord it doesn't talk anything about DHT. Cause i am not familiar with DHT, my question is: Can we say DHT is a consistent hashing technique?

3, is Chord deployed somewhere in current peer-to-peer systems? Based on this paper, Chord should attract lots of attention from the peer-to-peer systems' designers.

Reading On "RON"

Summary: This paper presents RON- resilient overlay network which tights the applications and routing to let end-to-end communications be unaffected in face of path outlets. RON is a novel way to deal with the underlying network protocol's problems, especially BGP's long convergence time caused by link failures. 

Background: BGP

Discussion:

This is a very good paper which has been cited by 1185 times. I think the following reasons which let this paper be so popular:

1, No matter RON is practical or not,  the idea in it is quite new that tries to solve underlying network problems in the end user perspective. (a new story of End to End argument?)

2, Real data from real world. The author deployed 16 RON nodes in the Internet and got convincing results to show the RON's effectiveness.

3, Authors themselves has realized the RON's problems and explained them clearly in paper.

reading on "ExOR: Opportunistic Multi-Hop Routing for Wireless Networks"

Summary: this paper presents ExOR which basically lets one node to send packets to several nodes and then chooses one of these nodes continues to send to several nodes till the packets reach the destination.  There are several challenges in ExOR. Authors built a packet format to solve these challenges. Through experiments on Roofnet, ExOR makes a big improvement on throughput than traditional routing scheme.

Background: ETX

Discussion:

this is a good paper and really smart idea. 

1, is ExOR really practical? 

2, i do think there are too much stuff in the ExOR packet header. Is it a good solution to augment the packet header?

reading on "A high-throughput path metric for multi-hop wireless routing"

Summary: this paper presents a new path metric called Estimated Transmission Count(ETX) which can be used to find higher throughput paths than using minimum-hop-count. The author briefly described DSDV and DSR and made them be capable to incorporate ETX. 

Background:

Discussion:

1, what is motivation for finding the higher throughput paths?

reading on "Modeling Wireless Links for Transport Protocols"

summary:this paper argues that because of the inaccurate modeling for the link layer, the studies on the transport layer have more or less problems. The authors briefly reviewed the different link characteristics, topologies , traffic pattern and performance metrics of cellular, WLAN and satellite networks. The paper lists all the aspect which should be taken consideration to model link layer and gives the methods to model them. At the end of the paper, the authors talked about some future work.

background: AQM

Discussion:

1, what is AQM? it looks like AQM is an very important concept. Did we talked about it before?

2, it is true that wireless links become one important part of the current Internet. Should we really make TCP work under such a mixed circumstance. I do think connection-split is a good idea although proved to be useless in Hari's paper.

3, is this paper the first one to talk about the cross-layer communication? What is the biggest problem to introduce the cross-layer communication mechanism to current network protocol stack?

Reading on "A Comparison of Mechanisms for Improving TCP Performance over Wireless Links"

Summary: this paper uses throughput and goodput as the metrics to compare different mechanisms for improving TCP performance. The authors classify the mechanisms into three classes: end to end improvement, link-layer protocols and split-connections. Details about different mechanisms are discussed. Based on the results of experiments using different mechanisms, the authors gave us some valuable conclusions. Some most important conclusions are as follows:1, the connection-split measure is useless; 2, through adjustment on the TCP protocol itself, the performance of TCP in wireless links will be improved a lot.

Background:some knowledge about TCP is necessary, for instance, fast-recovery, cumulative acknowledgement and etc.

reading on "MACAW"

summary: this paper proposed MACAW-a new MAC layer protocol for wireless networks. To solve the problems met in MACA, MACAW uses lots of solutions including back-off counter copy, per flow FIFO, ACK packet, DS packet and etc. Each of the solutions is used to target one specified problem. In the process of thinking about solutions, the authors put throughput fairness in the first order. This paper left the readers lots of future work. 

background: some basic knowledge about wireless communication

Discussion: First of all, this is a very good paper not because of its idea but because the inspiration it gave us. It tells us a new way to write a paper: list all the problems of the former solution, solve them one by one. If we can't find a perfect solution, we can leave it as an open problem.

1, the discussion about ACK is quite interesting. Retransmission through transport layer is too slow because of the long time-out. Therefore, the authors used link layer recovery. I wanna ask: does this method obey the golden "end to end argument" rule?

2, the simulator created by the authors is really smart which approximates the media by dividing the space into small cubes. we can discuss some issues in wireless simulators?

3, purely using tables not graph to tell the results is not good in my opinion. Why not use graph?