Predictive packet forwarding for a network switch
View Patent ↗A network switch includes a predictor using data in a packet to predict a flow for the packet. A forwarding engine forwards at least a portion of the packet on a switch fabric to an egress port in the switch determined from the predicted flow. The forwarding engine is operable to forward the packet on the switch fabric to the egress port determined from the predicted flow prior to a lookup module determining a flow from a lookup.
1. A network switch comprising:
a predictor to use data in a packet to predict a flow for the packet;
a memory to store bits of the packet as the packet is received by the network switch;
a forwarding engine to forward at least a portion of the packet on a switch fabric to an egress port determined from the predicted flow; and
a lookup module to perform a lookup to determine a flow for the packet,
wherein the forwarding engine is to forward the at least a portion of the packet on the switch fabric to the egress port determined from the predicted flow prior to the lookup module determining the flow, and the predictor is to determine the bits prior to the storing in the memory or at the same time of the storing in the memory.
2. The network switch of claim 1 , wherein the forwarding engine is to forward the at least a portion of the packet on the switch fabric to the egress port determined from the predicted flow prior to the lookup module performing the lookup.
3. The network switch of claim 1 , wherein the at least a portion of the packet is transmitted from the egress port prior to the lookup module performing the lookup.
4. The network switch of claim 1 , further comprising using a flow key determined by the lookup module to confirm the predicted flow is a correct flow for the packet.
5. The network switch of claim 1 , comparing a flow key determined by the predictor to a flow key determined from the data in the packet to confirm the predicted flow is a correct flow for the packet.
6. The network switch of claim 1 , wherein the predictor is to determine a signature from only some of the bits of a flow key of the packet and compares the determined signature to stored signatures to predict the flow.
7. The network switch of claim 6 , wherein the signature is generated from one of Fixed, Eager, Hash, Smart Hash, Eager Hash, and Smarty Eager Hash method.
8. The network switch of claim 6 , wherein the lookup module is to perform the lookup using the flow key in its entirety.
9. A flow prediction method for packet forwarding in a network switch comprising:
predicting a flow for a packet received at a network switch from some bits of a flow key;
storing bits of the packet as the packet is received;
determining the bits of the packet prior to the storing or at the same time of the storing;
forwarding at least a portion of the packet on a switch fabric to an egress port determined from the predicted flow; and
performing a lookup to determine a flow for the packet, wherein the forwarding the at least a portion of the packet on the switch fabric to the egress port determined from the predicted flow is performed prior to a lookup module completing the lookup.
10. The method of claim 9 , wherein the forwarding further comprises:
forwarding the at least a portion of the packet on the switch fabric to the egress port determined from the predicted flow prior to the lookup module performing the lookup.
11. The method of claim 9 , further comprising:
transmitting the at least a portion of the packet from the egress port prior to the lookup module performing the lookup.
12. The method of claim 9 , further comprising:
using the lookup to confirm the predicted flow is a correct flow for the packet.
13. The method of claim 9 , wherein the predicting the flow further comprises:
determining a signature from only some of the bits of the flow key for the packet; and
comparing the determined signature to stored signatures to predict the flow.
14. A line card for a network switch, the line card comprising:
at least one port to receive a packet;
a predictor to use data in the received packet to predict a flow for the packet;
a memory to store bits of the packet as the packet is received by the port; and
a forwarding engine to forward at least a portion of the packet on a switch fabric to an egress port determined from the predicted flow;
wherein the forwarding engine is to forward the at least a portion of the packet on the switch fabric to the egress port determined from the predicted flow prior to performing a lookup to determine a flow for the packet and the forwarding engine is to modify the at least a portion of the packet based on the flow, and the predictor is to determine the bits prior to the storing in the memory or at the same time of the storing in the memory.