Hierarchical label switching across multiple OSPF areas
AssigneeCisco Technology, Inc.
InventorDaniel C. Tappan
Life of this patent
Estimating the term…
Abstract
A router has a first interface to receive a packet from an external autonomous system and a second interface to transmit the packet as an outgoing packet to a border router. A processing engine places a first tag on the outgoing packet in accordance with a standard tag switching protocol. A shared field in the outgoing packet has at least one bit to indicate a use of the shared field, the at least one bit set by the processing engine to indicate the shared field carries a second tag, the second tag indicating a route from the border router to a destination of the packet.
Claims22
A router, comprising:
- a first interface to receive a packet from an external autonomous system;
- a second interface to transmit said packet as an outgoing packet to a border router;
- a processing engine to place a first tag on said outgoing packet in-accordance with a standard tag switching protocol;
- and
- a shared field in said outgoing packet having at least one bit to indicate a use of said shared field, said at least one bit set by said processing engine to indicate said shared field carries a second tag, said second tag indicating a route from said border router to a destination of said packet.
A router, comprising:
- means for receiving a packet from an external autonomous system;
- means for transmitting said packet as an outgoing packet to a border router;
- means for placing a first tag on said outgoing packet in accordance with a standard tag switching protocol;
- and
- means for setting at least one bit in a shared field in said outgoing packet to indicate said shared field carries a second tag, said second tag indicating a route from said border router to a destination of said packet.
A method for use in a router, said method comprising:
- receiving a packet from an external autonomous system;
- transmitting said packet as an outgoing packet to a border router;
- placing a first tag on said outgoing packet in accordance with a standard tag switching protocol;
- and
- setting at least one bit in a shared field in said outgoing packet to indicate said shared field carries a second tag, said second tag indicating a route from said border router to a destination of said packet.
Dependencies are inferred from the claim text.