EE E6761 Computer Communication
Networks
Sample Project Topics
The following is a list of possible project topics for ELEN 6761.
These are simply recommendations. It is o.k., and in fact encouraged,
if you come up with your own ideas for topics.
- TBIT Several versions of TCP
exist. Each version has various requirements and options that should
be provided as specified in various RFCs. TCP is designed such that
the TCP receiver is the same under these various versions, and that
the differences are implemented at the sender side of the protocol.
What is the fraction of servers that are implementing a particular
version of TCP? Are they implementing all of the options correctly?
TBIT is a tool devloped at ACIRI (AT\&T Center for Internet Research
at ICSI in Berkeley, CA) that connects with a server using a TCP
connection and probes the server by varying the behavior at the
receiver end in such a way that it is possible to distinguish between
versions, and can test whether certain options / requirements are
being met. Researchers at ACIRI have posed several questions that
their TBIT tool cannot yet detect, but that they are interested in
adding to the tool. For instance:
- Is the version of TCP really randomly choosing its initial
sequence number?
- CISCO routers sometimes drop packets whose ECN bit is set. How
often does this occur?
- The time between transmissions during TCP timeout is supposed to
increase exponentially. Is the version of TCP implementing this
correctly?
For more information, see the TBIT website on the web-page http://www.aciri.org/tbit. Groups
embarking on this project would likely get the opportunity to interact
with the folks at ACIRI, which is
in itself a fantastic opportunity.
- Soft State
Soft-state is a mechanism style used by communication protocols
in which a client node maintains some default state that it reverts to
if it is not contacted by its parent periodically. The mechanism
increases the fault tolerance of the network because when network
faults partition communication, the system reverts to a default
state. However, soft-state has a cost in terms of the bandwidth
required to simply keep the connection alive, as well as the automatic
termination of connections during a partition. Is there a good model
that can be used to examine these tradeoffs?
- Household IP
It is commonly stated that soon, every household device will
have its own IP address and will become a component of the Internet.
What sorts of changes need to be made to the current IP infrastructure
to support the needs, as well as the number, of these devices?
- Ad-hoc
routing Imagine a laptop or a cellphone acting not only
as an end-point receiving device but also as a router, forwarding
packets to other destinations. With a chain of these devices,
reliability could be improved (e.g., one would have less problems
receiving signals in certain areas like in the subway or behind tall
buildings). How should the ad-hoc routing and/or reliability
mechanism be designed? Are there tradeoffs in terms of power usage or
wireless bandwidth consumption?
- Nomadic DNS DNS was designed under the assumption that hosts would remain
fixed. However, it turns that people are not interested in reaching a
given host - they are more interested in reaching the information that
might exist on the host. DNS is not designed to handle information
that might reside on a set of hosts for a short period of time before
being moved to other sites. How can DNS be modified to support these
migration services, or should a new protocol be designed to replace
current DNS?
- RED Inference Random Early Detection (a.k.a., RED) is a policy being
implemented in Internet routers whereby packets are dropped
probabilistically, where the probability that a packet is dropped is
an increasing function of the exponentially weighted average of the
size of the router's buffer in use. Is RED working in practice?
Before this can be answered, one first needs to know to what extent is
RED being deployed. However, it is often not easy to ascertain this
information from ISPs. Can it be inferred from the end-hosts as to
whether or not a router, or set of routers along a given network path,
are using RED?
- Multi-Party Fair Share Multi-party applications, such as Internet video/audio
broadcasts, or tele-videoconferencing, have the potential to usurp
large shares of network bandwidth. How should these protocols be
designed so that they share bandwidth ``fairly'' with other
applications using the Internet? This problem has two interesting
parts: what is a ``fair'' share for such an application? Once it is
determined what is meant by a fair share, how can this fair share be
realized?
- SPOCs Several works have proposed that flows should not perform
congestion control in isolation, but that flows that are congested by
common points in the network should somehow cooperate. How can one
detect shared points of congestion in a network? If these points move
around, or if there are multiple points of congestion, what should the
policy be on aggregating flows together? What is the measure used to
determine whether or not to aggregate two flows?