Communication in networks suffers if a link fails. When the links are edges of a tree that has been chosen from an underlying graph of all possible links, a broken link even disconnects the network. Most often, the link is restored rapidly. A good policy to deal with this sort of transient link failures is swap rerouting, where the temporarily broken link is replaced by a single swap link from the underlying graph. A rapid replacement of a broken link by a swap link is only possible if all swap links have been precomputed. The selection of high quality swap links is essential; it must follow the same objective as the originally chosen communication subnetwork. For Project Guidance Visit: http://blog.ocularsystems.in OR Mail Us: info@ocularsystems.in Contact Us: 7385665306

1. Project Guidance: www.ocularsystems.in
Email: info@ocularsystems.in Call Us: 7385665306
A Distributed March 17
Algorithm for
2011
Finding All Best
Swap Edges of a
Minimum
Diameter Spanning
Tree
Communication in networks suffers if a link fails. When the links
Distributed
are edges of a tree that has been chosen from an underlying Systems,
graph of all possible links, a broken link even disconnects the
network. Most often, the link is restored rapidly..…
Minimal
Spanning tree
Ocular Systems, Shop No: 01, Swagat Corner Building, Near NarayaniDham Temple,
Katraj, Pune-46

2. A Distributed Algorithmfor Finding All Best Swap Edgesof a Minimum Diameter
Spanning Tree
Abstract:
Communication in networks suffers if a link fails.When the links are edges of a tree
that has been chosen froman underlying graph of all possible links, a broken link
evendisconnects the network. Most often, the link is restored rapidly.A good policy to
deal with this sort of transient link failures isswap rerouting, where the temporarily
broken link is replacedby a single swap link from the underlying graph. A
rapidreplacement of a broken link by a swap link is only possible if allswap links have
been precomputed. The selection of high qualityswap links is essential; it must follow the
same objective as theoriginally chosen communication subnetwork.
We are interestedin a minimum diameter tree in a graph with edge weights (so asto
minimize the maximum travel time of messages). Hence, eachswap link must minimize
(among all possible swaps) the diameterof the tree that results from swapping. We
propose a distributedalgorithm that efficiently computes all of these swap links, andwe
explain how to route messages across swap edges with acompact routing scheme. Finally,
we consider the computationof swap edges in an arbitrary spanning tree, where swap
edgesare chosen to minimize the time required to adapt routing incase of a failure, and
give efficient distributed algorithms fortwo variants of this problem.
Existing System
According to the previous technique, a message follows the normal routing table
information unless the next hop has failed; in this case, it is redirected towards a
precomputed link, called swap; once this link has been crossed, normal routing is
resumed. The choice of the swap edge is done according to some optimization criteria on
the resulting new route. The amount of precomputed information required in addition to
the routing table is rather small: a single link per each destination. Several efficient serial
algorithms have been presented to compute this information for several optimization
criteria distance, maximum,sum ,increment . Only the algorithm corresponding to
distance has been efficiently implemented in a distributed environment, while for the
other optimization criteria no distributed solution has been devised yet
Disadvantage:
once this link has been crossed, normal routing is resumed. The choice of the
swap edge is done according to some optimization criteria on the resulting new route.

3. Proposed System
For communication in computer networks, often only asubset of the available
connections is used to communicateat any given time. If all nodes are connected using
thesmallest number of links, the subset forms a spanning treeof the network. This has
economical benefits compared tousing the entire set of available links, assuming that
merelykeeping a link active for potentially sending messages inducessome cost.
Furthermore, as only one path exists betweenany communication pair, a spanning tree
simplifies routingand allows small routing tables.
Depending on the purposeof the network, there is a variety of desirable properties ofa
spanning tree. We are interested in a Minimum DiameterSpanning Tree (MDST), i.e., a
tree that minimizes the largestdistance between any pair of nodes, thus minimizing the
worstcase length of any transmission path, even if edge lengths arenot uniform. The
importance of minimizing the diameter of a spanning tree has been widely recognized ,
the diameter of a network provides a lower bound(and often even an exact one) on the
computation time of mostalgorithms in which all nodes participate.One downside of
using a spanning tree is that a single linkfailure disconnects the network. Whenever link
failures aretransient, i.e., a failed link soon becomes operational again, themomentarily
best possible way of reconnecting the networkis to replace the failed link by a single
other link, called aswap link. Among all possible swap links, one should choosea best
swap w.r.t. the original objective thatis in our case, a swap that minimizes the diameter of
theresulting swap tree.
Advantages:
The distributed computation of all best swaps has the further advantage of gaining
efficiency (against computing swap edges individually), because dependencies between
the computations for different failing edges can be exploited.
IMPLEMENTATION
Implementation is the stage of the project when the theoretical design is turned
out into a working system. Thus it can be considered to be the most critical stage in

4. achieving a successful new system and in giving the user, confidence that the new system
will work and be effective.
The implementation stage involves careful planning, investigation of the existing
system and it’s constraints on implementation, designing of methods to achieve
changeover and evaluation of changeover methods.
Modules:
Spanning Tree generation
For communication in computer networks, often only a subset of the available
connections is used to communicate at any given time. If all nodes are connected using
the smallest number of links, the subset forms a spanning tree of the network.
Minimum DiameterSpanning Tree(MDST)
A tree that minimizes the largest distance between any pair of nodes, thus
minimizing the worst case length of any transmission path, even if edge lengths are not
uniform. Essentially, the diameter of a network provides a lower bound (and often even
an exact one) on the computation time of most algorithms in which all nodes participate.
Swap link
One downside of using a spanning tree is that a single link failure disconnects the
network. Whenever link failures are transient, i.e., a failed link soon becomes operational
again, the momentarily best possible way of reconnecting the network is to replace the
failed link by a single other link, called a swap link. Among all possible swap links, one
should choose a best swap w.r.t. the original objective.
Swap rerouting
A good policy to deal with this sort of transient link failures is swap
rerouting, where the temporarily broken link is replaced by a single swap link from the

5. underlying graph. A rapid replacement of a broken link by a swap link is only possible if
all swap links have been precomputed.
Software Requirements:
Hardware Requirement:
 Minimum 1.1 GHz PROCESSOR should be on the computer.
 128 MBRAM.
 20 GB HDD.
 1.44 MB FDD.
 52x CD-ROM Drive.
 MONITORS at 800x600 minimum resolution at 256 colors minimum.
 I/O, One or two button mouse and standard 101-key keyboard.
Software Requirement:
 Operating System:Windows 95/98/2000/NT4.0.
 Technology : JAVA, JFC(Swing)
 Development IDE : Eclipse 3.x