Extending path computation element protocol to accommodate routing and wavelength assignment in wavelength switched optical networks

A network component, comprising:

• a path computation element (PCE) in communication with a path computation client (PCC),
• wherein the PCE is configured to receive a request from and send a reply to the PCC using PCE communication protocol (PCEP),
• wherein the request comprises:
• a lightpath constraint that indicates limits on wavelength usage along a lightpath;
• and
• a wavelength policy constraint that specifies an operator's policy information for wavelength assignment, and
• wherein the reply comprises an error message that indicates the PCE is not configured to calculate routing assignment and wavelength assignment.

A network component, comprising:

• a path computation element (PCE) in communication with a path computation client (PCC),
• wherein the PCE is configured to receive a request from and send a reply to the PCC using PCE communication protocol (PCEP),
• wherein the request comprises:
• a lightpath constraint that indicates limits on wavelength usage along a lightpath;
• and
• a wavelength policy constraint that specifies an operator's policy information for wavelength assignment, and
• wherein the reply comprises an error message that indicates that the request is not compliant with administrative privileges.

A network component, comprising:

• a path computation element (PCE) in communication with a path computation client (PCC),
• wherein the PCE is configured to receive a request from and send a reply to the PCC using PCE communication protocol (PCEP),
• wherein the request comprises:
• a lightpath constraint that indicates limits on wavelength usage along a lightpath;
• and
• a wavelength policy constraint that specifies an operator's policy information for wavelength assignment, and
• wherein the reply comprises an error message that indicates that an internal policy of the PCE has been violated.

A method implemented in a network component comprising a path computation element (PCE), the method comprising:

• communicating with a path computation client (PCC);
• receiving a request from the PCC using PCE communication protocol (PCEP), wherein the request comprises a lightpath constraint that indicates limits on wavelength usage along a lightpath and a wavelength policy constraint that specifies an operator's policy information for wavelength assignment;
• and
• sending a reply to the PCC using PCEP,
• wherein the reply comprises a no path indicator that indicates that no lightpath was found.