Layered multicast and fair bandwidth allocation and packet prioritization
Embodiments include an overlay multicast network. The overlay multicast network may provide a set of features to ensure reliable and timely arrival of multicast data. The embodiments include a congestion control system that may prioritize designated layers of data within a data stream over other layers of the same data stream. Each data stream transmitted over the network may, be given an equal share of the bandwidth. Addressing in routing tables maintained by routers in the may utilize summarized addressing based on the difference in location of the router and destination address. Summarization levels may be adjusted to minimize travel distances for packets in the network. Data from high priority data stream layers may also be retransmitted upon request from a destination machine to ensure reliable delivery of data.
1. A method comprising:
storing a routing table by a network node, the routing table containing a set of summarized destination addresses based upon a location of a destination machine, wherein the destination addresses are multi-field addresses and are summarized by comparing each field of the multi-field destination address with a respective corresponding field of an address of the network node in a sequential basis, starting with a most significant field of the multi-field destination address and continuing toward the least significant field of the multi-field destination address, field-by-field, identifying a first non-matching field, and filling all subsequent fields with a wildcard;
determining a path length for the summarized destination address;
determining if the routing table contains a previously summarized destination address for the destination machine;
comparing the path length for the summarized destination address with a path length for the previously summarized destination address;
updating the routing table with the summarized destination address only if the path length for the summarized destination address is shorter than the path length for the previously summarized destination address;
propagating routing table updates to neighboring routers if the routing table is updated with the summarized destination address, and not propagating routing table updates to neighboring routers if the routing table is not updated with the summarized destination address; and
forwarding data to the destination machine using a designated hop address associated with summarized address of the destination machine.
2. The method of claim 1 , wherein the location is a domain.
3. The method of claim 1 , further comprising:
adjusting a level of summarization to minimize a distance data traverses to reach the destination machine.
4. The method of claim 3 , wherein adjusting the level of summarization occurs at a border router adjacent a destination domain.
5. The method of claim 3 , further comprising:
receiving a subscription request from an adjacent node for a multicast group; and
tracking the adjacent node that sent the subscription request in a subscription table.
6. The method of claim 5 , further comprising:
forwarding subscription requests toward a source if not present in the subscription table.
7. The method of claim 1 , further comprising:
sending a leave group message to an adjacent node if a connection with a source is lost.
8. The method of claim 1 , further comprising:
forwarding multicast group data to each destination in an entry in a subscription table associated with a group source.