Being different from the DSDV which preserves a complete routing table
, AODV reduces the number of routing broadcasting by establishing the on-demand routing; it is an important improvement of AODV on DSDV.
Not only does the routing table
tell the call routing system which numbers to dial (and in what sequence) when a certain name or department is spoken, but it also ensures the transfer process conforms to the protocol required to correctly use the dialing pattern.
: As shown in fig.2, routing table
at each node stores the list of reachable nodes and their pheromone value.
If none of the routing tables
involved in a particular routing session contained the location of the destination, by default the networks would simply hand the packets back and forth continuously and the packets would never reach their final destination.
The routing table
is "local" because it only suggests what the "best" next node is, given the goal node of the course.
Compact routing tables
for graphs of bounded genus.
This is accomplished by having immediate access to more than 90% of the Internet routing table
within the center.
* An article in the April 2, 2001 issue of NetworkWorldFusion (http://www.nwfusion.com/news/2001/0402routing.html) warns that "Alarm bells are ringing in the Internet engineering community over an obscure statistic that indicates the Net is growing--in size and complexity--at a faster rate than today's routers can handle." The statistic in question is the number of entries in the Internet backbone routing table
. "After years of predictable growth, the size of the routing table
and traffic in it exploded during the past 6 months, topping 104,000 entries in March, compared with 75,000 a year ago.
He said: "We now have an `intelligent' scan that not only identifies where an item is but verifies it against a database, which in our case is a routing table
Before a geographic router can determine where to forward an incoming packet, it must first have a routing table
containing information about the network topology and geography.
Furthermore, it has a drawback of maintaining a routing table
in a zone of each node.
Route discovery occurs when a source node is request to communicate with a target node where a path is created and the route is saved in the routing table
. On the other hand, when a communication failure occurs or change of network topology, the routing maintenance procedure is activated.