Multicast Frame Transfer via Shared Virtual Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In real-time communication systems, such as industrial and in-vehicle networks, existing technologies face challenges in reducing the worst-case execution time for multicast transfer processing, particularly due to the need for deterministic operation and the inefficiencies in data copy processes during multicast and broadcast operations.
Innovation Solution
A communication apparatus is designed with a storage unit having a multicast storage area for each multicast group, where multicast frames are written directly into a shared virtual storage area, and descriptors are output to virtual machines, allowing them to read frames from this area without the need for multiple copies, thereby reducing the number of data copies and improving processing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multicast frames are copied to each virtual machine's storage area, then each virtual machine can access frames independently, but the number of data copy operations increases and worst-case execution time increases
Solution Approach 1:
The patent merges the frame storage functionality into a shared storage area accessible by all virtual machines, eliminating the need for separate copies in each VM's storage. The shared storage area is mapped to each VM's address space, allowing direct access without copying operations, thus reducing execution time while maintaining independent access capability through memory mapping.
Solution Approach 2:
The patent introduces a shared storage area as an intermediary between the frame receiver and multiple virtual machines. Instead of copying frames to each VM, the shared storage area acts as a mediator that all VMs can access through memory mapping, eliminating redundant copy operations while ensuring each VM can independently access the frames it needs.
2Ease of operation
If multicast frames are copied to each virtual machine, then data can be accessed independently, but processing efficiency decreases due to multiple copy operations
Solution Approach 1:
The patent combines the frame storage function into a single shared storage area that is memory-mapped to all virtual machines. This merging eliminates the need for separate frame copies in each VM, reducing processing overhead while maintaining independent access through virtual memory mechanisms.
Solution Approach 2:
The patent replaces physical data copying with virtual memory mapping. Instead of actually copying frame data to each VM's storage, the system creates virtual mappings to the shared storage area, providing the illusion of local copies without the actual data duplication, thus improving processing efficiency.
3Loss of time
If a shared virtual storage area is used for multicast frames, then the number of data copies is reduced, but system complexity increases due to memory mapping management
Solution Approach 1:
The patent implements self-service memory mapping management where the virtual switch automatically handles the mapping between virtual machine address spaces and the shared storage area. The system autonomously manages the mapping relationships without requiring external intervention, reducing the perceived complexity for users while maintaining efficient frame delivery.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to an arrangement, a communication apparatus (300; 300-2) includes a plurality of virtual machines (1), a storage unit (30), a transfer unit (22; 106), and a descriptor output unit (25). The storage unit (30) includes a multicast storage area (31) specified for each multicast group and storing a multicast frame addressed to virtual machines (1) belonging to a multicast group. The transfer unit (22; 106) writes the multicast frame into a multicast transfer virtual storage area (23) mapped to the multicast storage area (31). The descriptor output unit (25) outputs a descriptor of the multicast frame to the virtual machines (1) belonging to the multicast group. The virtual machine (1) includes a descriptor receiving unit (11; 64) and a reading unit (14; 63). The descriptor receiving unit (11; 64) receives the descriptor. When the descriptor is received by the descriptor receiving unit (11; 64), the reading unit (14; 63) reads the multicast frame from the multicast storage area (31) specified based on the descriptor.