Hybrid BRPC and H-PCE

In (Hernandez-Sola et al., 2010) a hybrid architecture between BRPC and H-PCE is proposed in order to increase the optimality of the resulting end-to-end path without increasing too much the number of control messages exchanged. “Additionally, a trade-off between shared routing information, scalability and security across domains is also obtained” (Hernandez-Sola et al., 2001). In the proposed architecture by default each child PCE executes the BRPC for path computation where the domain sequence is previously determined by a BGP protocol. In case the number of domains to be crossed (from a child source domain to the target domain) reaches a given threshold the child PCE delegates the path computation to the parent PCE. 

In the performance simulations presented in the paper the threshold value was fixed in 2 and 3 (referring to the number of domains to be crossed). The tests performed showed that the higher threshold value demand less interference of the parent PCE decreasing number of control messages, less computation burden to the parent PCE but in the other hand a subtle higher level of blocking probability.

Hernández-Sola, G.; Perelló, J.; Spadaro, S.; Moreno, A.; Agraz, F.; Comellas, J. & Junyent, G. (2010), Analysis of traffic engineering information dissemination strategies in PCE-based multi-domain optical networks, in 'Transparent Optical Networks (ICTON), 2010 12th International Conference on', pp. 1—4.