A method and system for provisioning circuits on multiple parallel links
with a single setup message is disclosed. A setup message specifying
links in a circuit path is transmitted to switches along the circuit
path. If a switch determines that a link specified in the setup message
has insufficient bandwidth for the circuit, the switch substitutes a
parallel link having sufficient bandwidth for the specified link in the
circuit path. The setup message can indicate whether substitution for a
link is permitted. This can be used to prevent substitution for links
when provisioning service routes for new circuits in order to maintain
diversity requirements, while allowing substitution for links when
provisioning restoration routes for failed circuits in order to reduce
restoration time.