The invention provides an establishing method of
label switching path of minimizing path occupy cost in a
multi protocol switching network. A link is wiped out when the not-reserved bandwidth is smaller than the bandwidth r of
label switching path established by request in
network topology. In the residual
network topology, the
residual bandwidth of each link is used as routing tolerance, and a priority
algorithm of shortest path based on obligation is operated to find an optimal path of the said
label switching path. For the said selected link on the optimal path, the
residual bandwidth is analyzed whether it is more than or equal to the bandwidth r of
label switching path established by request if yes the occupation is needless, if not, the occupation is necessary, the occupation formula is Y=alpha* p+ epsilon / |(b-r)|+sigma*n + theta*b. The invention not only establishes a
label switching path for a new LSP request in minimal occupy cost, and obtains load balance and effectively increases the level of network
resource utilization.