IP ID Field Sequence Numbering for Packet Loss Detection

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Solution Overview

Problem

Current technologies for monitoring packet loss in streaming media over IP networks lack a protocol field to track sequence numbers, leading to inefficiencies in detecting out-of-sequence and missing packets, especially in layer 3 protocols which do not inherently support such functionality, resulting in increased network overhead when higher layer protocols are used.

Innovation Solution

A method and system that instrument packetized network traffic by replacing the IP ID field with sequence numbers using a compute engine and filter, allowing for the detection of packet loss without requiring modifications to existing stream sources or employing higher layer protocols, thereby enabling the identification of missing or out-of-sequence packets within layer 3 IP compatible networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If layer 4 protocols (RTP/TCP) are used to detect packet loss through sequence numbers, then packet loss detection capability is improved, but network overhead and protocol complexity increase

Engineering Contradiction:

Improvepacket loss detection capabilityVSAvoidprotocol overhead

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of adding sequence number functionality to layer 3 IP protocol (which would increase complexity), the invention uses layer 2 frame sequence numbers and reverses the detection logic by having the receiver track expected sequence numbers and detect losses without requiring the sender to embed sequence numbers in the payload. This inverts the traditional approach where the sender must provide sequence information.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention introduces an intermediary mechanism at layer 2 (data link layer) that provides sequence numbering functionality without requiring changes to layer 3 IP protocols. The layer 2 frame structure acts as a mediator that carries sequence information naturally, avoiding the need to embed sequence numbers in layer 4 protocol headers or payloads.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If higher layer protocols are employed to track sequence numbers, then out-of-sequence packet detection is improved, but network utilization efficiency deteriorates

Engineering Contradiction:

Improveout-of-sequence packet detectionVSAvoidnetwork utilization efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The invention inverts the traditional packet loss detection approach by having the receiver proactively track expected sequence numbers and detect anomalies, rather than requiring the sender to embed comprehensive sequence information in each packet. This reduces the data overhead in transmitted packets while maintaining detection capability.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention extracts sequence numbering functionality from higher layer protocols and relocates it to layer 2, where it can be implemented using existing frame structure elements. This extraction eliminates the need for redundant sequence number fields in layer 4 protocols, improving network utilization efficiency.

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If IP ID field is replaced with instrumentation containing sequence numbers, then packet loss characterization capability is improved, but compatibility with existing IP systems deteriorates

Engineering Contradiction:

Improvepacket loss characterization capabilityVSAvoidcompatibility with existing IP systems

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The invention introduces a layer 2 intermediary that adds sequence numbering functionality without modifying layer 3 IP packets. The instrumentation is inserted at the data link layer, allowing existing IP systems to operate unchanged while gaining enhanced packet loss characterization capabilities through the layer 2 wrapper.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention segments the packet loss detection functionality into separate layers: layer 2 handles sequence tracking and loss detection, while layer 3 IP handles routing and forwarding. This segmentation allows each layer to perform its specialized function without compromising the other, maintaining IP system compatibility while adding detection capabilities.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS7801127B2System and method for creating a sequence number field for streaming media in a packet-based networks utilizing internet protocol

Publication Date: 2010.09.21 INEOQUEST TECHNOLOGIES INC

AI summary

Streaming media network streams are modified using a sequence field with the IP layer 3 protocol compatible with already deployed IP switching systems except as noted for device and system testing and operational monitoring which can be used to detect the loss or out of order delivery of packets belonging to a stream. This approach can also provide the ability to numerically characterize the loss in terms of total loss, loss burst size, and loss frequency. By utilizing the bit locations of the IP-defined datagram Identification (ID) field and a unique numerical sequence, loss and out of order delivery may be tracked while avoiding the overhead and complexity associated with added upper layer protocols while gaining other key advantages such as in-situ marking of stream attributes.