ion on two cases, which are probably the most important: 1. The PIC simply substitutes a number of DWDM interfaces in a 10 Gbit/s line card. 2. The PIC is used to implement 100 Gbit/s transmission by parallelizing 10 wave- lengths in a 100 Gbit/s card. Next Generation Networking: Enabling Technologies, Architectures, and Performances In the first case, the GMPLS path at the transport layer is transported via a single 10 Gbit/s wavelength. Each wavelength represents a branch of an independent GMPLS route, even if they are generated by the same physical device. On top of this, every wavelength multiplexed different channels as defined in Chapter 3, Section 3.2.7. The fact that the PIC is a single physical component, implies that when one logical port experiments a failure (e.g., due to a laser failure) all the GMPLS paths traveling through the PIC have to be switched in protection, even if all but one of them are correctly working. This operation is needed to assure that the failed PIC can be substituted without affecting the traffic. In order to manage this operation at the protocol level, a correspondence has to be stated among all the paths traveling through a PIC, for example, introducing a new header field. In the second case, a single PIC corresponds to a single logical GMPLS port, thus having a single address. The wavelengths generated by the same PIC have to be considered by the control plane as a single path. For example, they have to be routed along the same route and travel always through the same PICs. Moreover, when one of them fails, all of them have to be rerouted along the same protection route, since logically those are the same channel. This problem can be solved also with the present version of GMPLS, where this situation is considered (see Chapter 8). Taking into account both these elements would require quite an update of GMPLS rout- ing and restoration protocols at the physical layer that have to be carried out by IETF and OIF before a real ODN deployment can happen. A similar problem concerns