VoIP Call Server ALG Function Extraction
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Solution Overview
Problem
The existing VoIP systems face limitations when using Network Address Translation/Port Translation (NAPT) technology, particularly in supporting VoIP services across private and public networks, due to complications and post-dial delays caused by the need for Application Level Gateways (ALGs) and the reassembly of packets, which are not efficiently handled by routers.
Innovation Solution
An apparatus and method for voice processing in VoIP systems that includes a call server and a data server, where the call server sets a public media gateway address corresponding to a private media gateway address in a packet data unit (PDU) and performs a VoIP application level gateway function, converting private signaling addresses to public signaling addresses, thereby eliminating the need for ALG functions in routers and reducing post-dial delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If Application Level Gateway (ALG) functions are implemented in routers to support VoIP services with NAPT technology, then network address translation capability is improved, but post-dial delays and system complexity increase
Solution Approach 1:
The patent extracts the ALG function from the router and relocates it to a dedicated VoIP server. This separation removes the time-consuming packet capture, analysis, and reassembly operations from the router's fast path, eliminating post-dial delays while maintaining VoIP service support capability. The router performs only basic NAPT, while the VoIP server handles application-level gateway functions.
Solution Approach 2:
The patent introduces a dedicated VoIP server as an intermediary between the router and the VoIP application. This mediator handles the complex ALG functions including packet analysis and address translation in the PDU payload, allowing the router to operate efficiently without these time-consuming operations. The VoIP server acts as a buffer that processes VoIP-specific protocols without impacting router performance.
2Adaptability or versatility
If ALG functions are implemented in routers to perform packet analysis and reassembly, then VoIP signaling support is improved, but device complexity increases
Solution Approach 1:
The patent extracts the complex ALG functionality from the router and places it in a dedicated VoIP server. The router's complexity is reduced to basic NAPT operations, while the VoIP server handles packet capture, analysis, and reassembly. This functional separation maintains comprehensive VoIP signaling support while significantly simplifying the router's architecture.
Solution Approach 2:
The patent segments the VoIP support functionality into two distinct components: basic NAPT in the router and advanced ALG functions in the VoIP server. This segmentation allows each component to be optimized independently - the router for high-speed packet forwarding and the server for complex protocol analysis - thereby reducing overall system complexity while maintaining full VoIP signaling support.
3Quantity of substance
If NAPT technology is used to convert private IP to public IP, then IP address utilization is improved, but network compatibility issues arise
Solution Approach 1:
The patent introduces a VoIP server as an intermediary that maintains translation tables mapping private IP addresses to public IP addresses. This mediator ensures that NAPT translations are consistent and reliable across the network, resolving compatibility issues while maintaining efficient IP address utilization. The server coordinates address translations to ensure proper routing and communication between private and public networks.
Data Source
AI summary
An apparatus and method for voice processing of VoIP are disclosed. The method includes: allowing a call server to perform a VoIP application level gateway (ALG) function and to set a public media gateway address corresponding to a private media gateway address of the call server in a packet data unit (PDU) of a VoIP packet to perform VoIP signaling; allowing the call server to set a private signaling address in an IP header of the VoIP packet and to transmit the corresponding VoIP packet to a data server; and allowing the data server to convert the private signaling address set in the IP header of the VoIP packet received from the call server into a public signaling address and to transmit the converted address to a destination through the Internet. Since the data server does not perform the VoIP ALG function but performs only a network address translation/port translation (NAPT) task for the IP header, a task load due to correction of data set in the PDU may be omitted, so that a quality of the VoIP service may be enhanced.