Method and apparatus for generating forward overrides in a packet switch
AssigneeMosaid Technologies Incorporated
InventorDavid A. Brown
Life of this patent
Estimating the term…
Abstract
A memory is successively searched using the contents of a header included in a data packet in order to select a forwarding entry for the data packet. The searches use a header field for a different protocol layer. A next field stored in a forwarding entry is used to determine if another search is required. The data packet is forwarded according to the forwarding override stored in the selected forwarding entry selected from the final successive search. The received data packet is forwarded to a host processor, through the switch, to both the host processor and through the switch, or the received data packet is not forwarded, dependent on the selected forward override.
Claims31
A switch comprising:
- a memory comprising at least one forwarding entry, the forwarding entry including a forward override entry and a next field;
- and
- forward override logic which, for a data packet received by the switch, successively searches the memory for forwarding entries matching portions of the received data packet, extracts the forward override from a matching forwarding entry and determines whether to perform another search of the memory dependent on the state of the next field in a current forwarding entry.
A method for selecting a forward override for a received data packet in a switch comprising the steps of:
- providing a memory, the memory comprising at least one forwarding entry, the forwarding entry including a forward override;
- successively searching the memory for forwarding entries matching portions of a received data packet;
- determining whether to perform another search of the memory dependent on the state of a next field in a current forwarding entry;
- and
- extracting the forward override from a matching protocol entry.
A switch comprising:
- a memory comprising at least one forwarding entry, the forwarding entry including a forward override;
- means for successively searching the memory for forwarding entries matching portions of a received data packet;
- means for determining whether to perform another search of the memory dependent on the state of a next field included in the forwarding entry;
- and
- means for extracting the forward override from a matching forwarding entry.
A switch comprising:
- a protocol CAM comprising at least one forwarding entry, the forwarding entry including a forward override and a next field;
- and
- forward override logic which, for a received data packet, successively searches the protocol CAM for forwarding entries matching portions of the received data packet and extracts the forward override from a matching forwarding entry and determines whether to perform another search of the protocol CAM dependent on the state of the next field in a current forwarding entry.
A method for selecting a forward override for a received data packet in a switch comprising the steps of:
- providing a protocol CAM, the protocol CAM comprising at least one forwarding entry, the forwarding entry including a forward override;
- determining whether to perform another search of the protocol CAM dependent on the state of a next field in a current forwarding entry;
- and
- extracting the forward override from a matching protocol entry.
A switch comprising:
- a protocol CAM comprising at least one forwarding entry, the forwarding entry including a forward override;
- means for successively searching the protocol CAM for forwarding entries matching portions of a received data packet;
- means for determining whether to perform another search of the protocol CAM dependent on the state of a next field included in a current forwarding entry;
- and
- means for extracting the forward override from a matching forwarding entry.
Dependencies are inferred from the claim text.