Hardware Multicast Tunnels to Reduce Control-Plane Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multicast communication in networks experiences latency due to the time-consuming process of programming hardware states in packet-forwarding ASICs by the control plane, which is necessary for fast-path data forwarding.
Innovation Solution
Offload certain multicast control plane functions to hardware logic units, specifically using existing hardware tunnel logic to create persistent tunnels between source-side and client-side designated routers, reducing the need for control plane involvement in programming packet-forwarding ASICs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the control plane programs hardware states in packet-forwarding ASICs for multicast data forwarding, then fast-path data forwarding is enabled, but packet transmission latency increases due to the time-consuming programming process
Solution Approach 1:
The patent extracts the multicast control plane functions from the software control plane and implements them in hardware logic units. Specifically, the hardware logic units perform service discovery, tunnel establishment, and packet forwarding operations that were previously handled by software, thereby eliminating the time-consuming software-to-hardware programming step and reducing packet transmission latency
Solution Approach 2:
The hardware logic units perform service discovery and tunnel establishment operations in advance before actual multicast data transmission begins. By pre-establishing the forwarding paths and hardware states needed for fast-path forwarding, the system eliminates the need for time-consuming runtime programming of packet-forwarding ASICs, thus reducing transmission latency
2Loss of time
If hardware tunnel logic is used to create persistent tunnels for multicast data transmission, then packet transmission latency is reduced, but device complexity increases
Solution Approach 1:
The patent makes the existing hardware tunnel logic units multi-functional by enabling them to perform both unicast tunnel operations and multicast control plane functions. The same hardware logic units that previously handled only unicast tunneling now also perform service discovery, tunnel establishment, and multicast packet forwarding, thereby reducing the need for additional dedicated hardware and minimizing the increase in device complexity
Solution Approach 2:
The patent merges the multicast control plane functions with the existing hardware tunnel logic units. Instead of creating separate dedicated hardware for multicast operations, the invention combines multiple functions (service discovery, tunnel establishment, and packet forwarding) into the existing hardware tunnel logic, thereby achieving latency reduction while minimizing the increase in device complexity
Data Source
AI summary
One aspect can provide a system and method for tunnel-based multicasting. During operation, a source-side designated router (DR) coupled to a source device of a multicast group can broadcast a service-advertisement packet and receive a response packet from a client-side DR coupled to one or more client devices within the multicast group. The source-side DR can determine an address of the client-side DR based on the received response packet and establish a hardware-based communication tunnel between the source-side DR and the client-side DR using the address of the client-side DR. Establishing the hardware-based communication tunnel can include using hardware logic units to encapsulate multicast data packets originating from the source device. The source-side DR can further send, over the hardware-based communication tunnel, multicast data packets originating from the source device to the client-side DR, which forwards the multicast data packets to the client devices within the multicast group.