Handling data packets received at a routing node

摘要

A method applied in a routing node, and a forwarding engine implemented in a routing node, are provided for handling data packets received at the routing node. A N-tuple comprising N elements is extracted from a first header of a data packet. A default meta-field is added to the N elements, providing a N+1-tuple. The N+1-tuple is used to make a first lookup of inspection rules. The default meta-field makes the inspection rules apply to the first header. The data packet is handled according to a result of the first lookup, wherein a possible outcome is a finding of a second header within the data packet. If a second header is found, a new meta-field value is set and a second lookup is made. The second lookup of the inspection rules is made according to N elements from the second header and the new value of the meta-field.

主权项

1. A method of handling a data packet received in a routing node, the method comprising the steps of:
creating an N+1-tuple based on N elements of a first header of the data packet and a meta-field having an initial value; and applying, in the routing node, inspection rules based solely on inspection of the N+1-tuple, to determine a processing of the data packet, wherein the processing associated with at least one of the inspection rules comprises:
modifying the N+1-tuple by changing the meta-field to a different value, indicative of a second header encapsulated in a payload of the data packet, and by populating the remaining fields of the N+1-tuple with N elements from the second header of the data packet; andre-applying, in the routing node, the inspection rules based solely on inspection of the modified N+1-tuple, to determine the processing of the data packet.