For reasons of survivability, many methods have been introduced to Automatically Switched Optical Network (ASON),
such as path protection. In path protection, the protection path is link-disjoint, node-disjoint or risk-disjoint with the
working path, which can improve the survivability of network. The complete risk-disjoint routing algorithm (CRDRA) is
the most popular algorithm in protection path selection at present, in which the links sharing same risk with those
contained in the working path are pruned away from the available resources when calculating protection path. By using
this algorithm, the survivability of network can be enhanced; but the number of connections which can be successfully
routed over current network drops. In this paper, a novel disjoint path selection scheme (DPSS) based on shared risk link
group (SRLG) is proposed. In this algorithm, the risk-sharing links are not removed, but to be partially pruned away
according to their availability and the weight of remained risk-sharing links should be adjusted to a proper value.
Selecting protection path with DPSS, the number of connections that can be successfully routed will increase; in the
mean time we can achieve a relative good survivability. Routing simulations have been done over mesh networks to
compare the suggested DPSS with link-disjoint routing algorithm (LDRA) and CRDRA. With the simulation results, a
conclusion can be made on the performance of different algorithms.