Longest prefix matching (LPM) using a fixed comparison hash table
First Claim
Patent Images
1. A method of forwarding Internet Protocol (IP) packets, comprising:
- producing at least one fixed-length key having a predetermined number of bits in response to an IP address in an IP packet;
hashing at least a portion of the fixed-length key to obtain a hash value; and
comparing the fixed-length key with a key value stored in each data item in a hash bucket associated with the hash value to find the data item that has the key value that matches the fixed-sized key and to obtain from that data item routing information that is used to forward the IP packet.
6 Assignments
0 Petitions
Accused Products
Abstract
Described are an apparatus and method of forwarding Internet Protocol (IP) packets. At least one fixed-length key having a predetermined number of bits is produced in response to an IP address in an IP packet. At least a portion of the fixed-length key is hashed to obtain a hash value. The fixed-length key is compared with a key value stored in each data-item in a hash bucket associated with the hash value to find the data item that has the key value that matches the fixed-sized key and to obtain from that data item routing information that is used to forward the IP packet.
55 Citations
20 Claims
-
1. A method of forwarding Internet Protocol (IP) packets, comprising:
-
producing at least one fixed-length key having a predetermined number of bits in response to an IP address in an IP packet;
hashing at least a portion of the fixed-length key to obtain a hash value; and
comparing the fixed-length key with a key value stored in each data item in a hash bucket associated with the hash value to find the data item that has the key value that matches the fixed-sized key and to obtain from that data item routing information that is used to forward the IP packet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An apparatus for forwarding IP packets, comprising:
-
a key generator producing a fixed-length key having a predetermined number of bits in response to an IP address;
a hash value generator hashing a portion of the key to produce a hash value; and
a comparator comparing the fixed-length key with a key value stored in each data item in a hash bucket associated with the hash value to find the data item that has the key value that matches the fixed-sized key and to obtain from that data item routing information that is used to forward the IP packet. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification