A Fast Re-Route Method
We present a method to find an alternate
path, after a link failure, from a source node to a destination node, before
the Interior Gateway Protocol (e.g., OSPF or IS-IS) has had a chance to reconverge
in response to the failure. The target application is a small (up to tens of
nodes) regional access subnetwork of a service provider’s network, which is a
typical access scale encountered in practice. We illustrate the method and
prove that it will find a path if one exists.
EXISTING SYSTEM
The existing system describes
the concept of multipath routing from
the source to root within the network. It also have various techniques
to handle data loss, delayed timing, loss
of acknowledgement . but it did not
describe how the packet to redirected once node within the path is unavailable
or corrupted.
PROPOSED SYSTEM
we present a method to find an alternate path, after a link failure,
from a source node to a destination node. Since reconvergence of an Interior
Gateway Protocol (IGP) (e.g., OSPF or IS-IS) can take hundreds of milliseconds,
there is a need for a method that will find an alternate path in less time than
this. The target application is a small (up to tens of nodes) access subnetwork
of a service provider’s network, which is a typical scale encountered in
practice; a service provider typically has many such small regional access networks.
Consider a source node s sending data to destination node d. Suppose some
link (i, j) on the shortest path from s to d fails. An IGP will find an alternate path
from s to d that avoids (i, j) (assume
such a path exists). However, IGP re-convergence may take hundreds of
milliseconds or even seconds, and the packet loss during this time period may
be unacceptable. Fast
Re-Route (FRR) methods establish a new path from s to d in much less time than required for IGP
re-convergence.
MODULE DESCRIPTION:
Fast Reroute
Method:
We now present the details of the
method. Let G = (N,A) be
an undirected connected graph with node set N and arc set A. For x ∈ N, let N(x) be
the set of neighbors of x, where a neighbor of x is a node one arc away from x. We associate
with each undirected arc (i, j) ∈ A a cost
c(i, j),
and require each c(i, j) to be a positive integer. (The integer valued
restriction can always be met by approximating, to the desired accuracy, each
arc cost by an improper fraction, and then multiplying all the fractions by the
least common multiple of the fraction denominators.) For i, j ∈ N, let c_(i, j) be
the cost of the shortest path in G between i and j. When using Route(s, d) for
fast re-route in the event of an arc failure, which is the target application, c_(i, j) represents the
shortest path cost before
the IGP has reconverged in response to the link
failure.
Multipath Routing:
Multipath routing is a promising routing
scheme to accommodate these requirements by using multiple pairs of routes
between a source and a destination. Multipath routing is the routing technique of using
multiple alternative paths through a network, which can yield a variety of
benefits such as increased bandwidth, or improved security. The multiple paths
computed might be overlapped, edge-disjointed or node-disjointed with each
other. Extensive research has been done on multipath routing techniques.
Failure Recovery:
Techniques developed for fast recovery from
single-link failures provide more than one forwarding edge to route a packet to
a destination. Whenever the default forwarding edge fails or a packet is
received from the node attached to the default forwarding edge for the
destination, the packets are rerouted on the backup ports. In the authors present a framework for IP fast
reroute detailing three candidate solutions for IP fast reroute that have all
gained considerable attention. when a forwarding link on a tree fails, the
packet may be switched to the other tree.
System Configuration:-
H/W System
Configuration:-
Processor
- Pentium –III
Speed - 1.1 Ghz
RAM - 256
MB(min)
Hard Disk - 20 GB
Floppy Drive - 1.44 MB
Key Board - Standard Windows Keyboard
Mouse - Two or Three Button Mouse
Monitor - SVGA
S/W System Configuration:-
Operating
System :Windows XP
Front End : JAVA,RMI, SWING
