A method comprising: receiving , by a network node in a packet switched domain, a control signaling instruction from a controller, wherein the control signaling instruction comprises routing information, the routing information indicating at least one egress next-hop or egress pathway and at least one of a link-based flow transport protocol, a path-based flow transport protocol, and a source-based flow transport protocol, and wherein the at least one egress next-hop or egress pathway corresponds to one of the flow transport protocols; receiving , by the network node, a traffic flow or a traffic flow portion over an ingress link; and transmitting , by the network node, the traffic flow or the traffic flow portion to next hop network nodes over the at least one egress next-hop or egress pathway; wherein the control signaling instruction indicates the path-based transport protocol or the source-based transport protocol, and wherein transmitting the traffic flow or the traffic flow portion to next hop network nodes over the at least one egress next-hop or egress pathway comprises: appending path information to packets in the respective portions of the traffic flow prior to forwarding respective portions of the traffic flow over the at least one egress next-hop or egress pathway; wherein the path information includes a path identifier when the control signaling instruction indicates the path-based transport protocol, and wherein the path information includes a list of next-hop identifiers when the control signaling instruction indicates the source-based transport protocol, the list of next-hop identifiers defining next-hop network nodes along the corresponding egress pathway. receiving , by a network node in a packet switched domain, a control signaling instruction from a controller, wherein the control signaling instruction comprises routing information, the routing information indicating at least one egress next-hop or egress pathway and at least one of a link-based flow transport protocol, a path-based flow transport protocol, and a source-based flow transport protocol, and wherein the at least one egress next-hop or egress pathway corresponds to one of the flow transport protocols; receiving , by the network node, a traffic flow or a traffic flow portion over an ingress link; and transmitting , by the network node, the traffic flow or the traffic flow portion to next hop network nodes over the at least one egress next-hop or egress pathway; wherein the control signaling instruction indicates the path-based transport protocol or the source-based transport protocol, and wherein transmitting the traffic flow or the traffic flow portion to next hop network nodes over the at least one egress next-hop or egress pathway comprises: appending path information to packets in the respective portions of the traffic flow prior to forwarding respective portions of the traffic flow over the at least one egress next-hop or egress pathway; wherein the path information includes a path identifier when the control signaling instruction indicates the path-based transport protocol, and wherein the path information includes a list of next-hop identifiers when the control signaling instruction indicates the source-based transport protocol, the list of next-hop identifiers defining next-hop network nodes along the corresponding egress pathway. appending path information to packets in the respective portions of the traffic flow prior to forwarding respective portions of the traffic flow over the at least one egress next-hop or egress pathway; wherein the path information includes a path identifier when the control signaling instruction indicates the path-based transport protocol, and wherein the path information includes a list of next-hop identifiers when the control signaling instruction indicates the source-based transport protocol, the list of next-hop identifiers defining next-hop network nodes along the corresponding egress pathway. <EOS>