Establishing source-routed bidirectional connections over the unidirectional ASON/GMPLS carisma testbed

The multiprotocol label switching (MPLS) standard defined by the Internet Engineering Task Force do not consider bidirectionality. In effect, to have bidirectionality two different label switched paths (LSP) have to be established. On the contrary, the generalized multiprotocol label switching (GMPLS) paradigm, by introducing a new object to the signalling protocol, supports bidirectionality. However it does not rely to unidirectional optical connections over unidirectional optical rings. This paper describes two solutions implemented in the ASON/GMPLS CARISMA network, and some experimental results regarding the establishment of soft-permanent connections are presented and discussed.