Optical telecommunications network
AssigneeBritish Telecommunications public limited company
InventorsDavid Cotter, Martin C. Tatham
Life of this patent
Estimating the term…
Abstract
A packet carried on an optical network is routed by carrying out a logic operation on an address word carried in a packet header and a predetermined discriminator word. A routing decision is made in accordance with the result of the logic operation. The logic operation may be a bit-wise Boolean AND operation. An additional logic operation may be carried out with an additional discriminator word to determine whether the packet is destined for a remote region of the network. In this case, the packet may be steered directly to the remote region.
Claims27
A method of routing a packet at a routing node on an optical network, comprising the steps of:
- carrying out in the optical domain a logic operation on an address word carried in a packet header and a discriminator word chosen from a set of discriminator words smaller in number than the set of address words for said optical network or domain of said optical network in which said node is located;
- and
- routing said packet based on the direct result of the logic operation.
A method according to any one of the preceding claims, wherein the header of each packet includes an address comprising a plurality of address words corresponding to different sub-fields of the address.
A node for routing a packet carried on an optical network comprising:
- a routing decision unit arranged to carry out in the optical domain a logic operation on an address word carried in the header of the packet and a predetermined discriminator word;
- and
- a switch responsive to the routing decision unit and arranged to route the packet in different directions depending on the result of the logic operation.
An optical network comprising a plurality of nodes, each node having a different respective address, and each node including
- a routing decision unit programmed with a discriminator word chosen from a set of discriminator words smaller than the number of address words and arranged to carry out a logic operation in the optical domain on said address word and the respective discriminator word;
- and
- a switch responsive to the routing decision unit and arranged to route respective packets in different directions depending on the result of the logic operation.
A method of routing a packet at a node of an optical network, comprising the steps of:
- logically combining in the optical domain address data for said packet and discriminator data for discriminating between address data for which a first routing direction is appropriate and address data for which a second routing direction is appropriate;
- and
- routing said packet in one or the other of the first and second routing directions based on the result of the logical combination.
A node for routing a packet on an optical network, comprising:
- logic circuitry for logically combining in the optical domain address data for said packet and discriminator data for discriminating between address data for which a first routing direction is appropriate and address data for which a second routing direction is appropriate;
- and
- a switch for routing said packet in one or the other of the first and second routing directions based on the result of the logical combination.
Dependencies are inferred from the claim text.