Method and apparatus for packet grooming and aggregation
View Patent ↗A method and apparatus for building a packet grooming and aggregation engine is disclosed. The grooming and aggregation engine can be applied to the network for providing flexible aggregation and service multiplexing functions. A method and apparatus achieves the intended function that is easy to implement and easy for the network operator to manage, yet provides enough flexibility to mix and match various services at the edge node of the network. One specific embodiment of the patent is an Ethernet over SONET mapping system where user traffic is aggregated and groomed into SONET transport virtual concatenation channels.
1. A method of packet grooming and aggregation within an Ethernet over SONET/SDH system (EOS system), said method comprising:
receiving a data packet tagged according to an encapsulation scheme and including a tag and a port or channel ID;
providing an input client frame from said data packet to a header unit;
extracting a search key including said port or channel ID and said tag from said input client frame via said header unit;
correlating said search key via a lookup engine to a match in a flow database to determine flow context;
modifying said input frame via a tag editor according to said flow context;
buffering said input client frame via a flow FIFO;
applying discard policies to said flow FIFO based on said flow context; and
scheduling said input client frame via a scheduler of the flow FIFO for transmission into output channels according to output channel status and flow quality of service parameters, wherein said correlating step occurs in accordance with a combined ingress table and egress table in a bi-directional lookup manner, and further including the steps of:
receiving said search key,
upon determining an ingress lookup,
performing a first wildcard linear search of said search key against predetermined ingress flow fields of a bi-directional flow database,
fetching flow context from said egress flow fields of said bi-directional flow database,
upon determining an egress lookup,
performing a second wildcard linear search of said search key against predetermined egress flow fields of a bi-directional flow database,
fetching flow context from said egress flow fields of said bi-directional flow database,
modifying a portion of said egress flow fields according to predetermined rules, and
outputting said flow context.
2. The method of packet grooming and aggregation as claimed in claim 1 wherein said scheduling step occurs in accordance with said flow context.
3. The method of packet grooming and aggregation as claimed in claim 2 further including the steps of:
receiving said search key,
performing a wildcard linear search against predetermined search key fields of said flow database,
fetching said flow context from said flow database, and
outputting said flow context.