Negative-Acknowledgment (Nack)-Oriented Reliable Multicast (Norm) Protocol

By Adamson, B.

Book Id: WPLBN0000693355
Format Type: PDF eBook:
File Size: 0.2 MB
Reproduction Date: 2005

Title:	Negative-Acknowledgment (Nack)-Oriented Reliable Multicast (Norm) Protocol
Author:	Adamson, B.
Volume:
Language:	English
Subject:	Business Strategy, Environmental Economics, Fine Arts
Collections:	Technical eBooks and Manuals Collection, Technical eBooks Collection
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Citation APA MLA Chicago Adamson, B. B. (n.d.). Negative-Acknowledgment (Nack)-Oriented Reliable Multicast (Norm) Protocol. Retrieved from http://self.gutenberg.org/

Description
Technical Reference Publication

Excerpt
Introduction: The Negative-acknowledgment (NACK) Oriented Reliable Multicast (NORM) protocol is designed to provide reliable transport of data from one or more sender(s) to a group of receivers over an IP multicast network. The primary design goals of NORM are to provide efficient, scalable, and robust bulk data (e.g., computer files, transmission of persistent data) transfer across possibly heterogeneous IP networks and topologies. The NORM protocol design provides support for distributed multicast session participation with minimal coordination among senders and receivers. NORM allows senders and receivers to dynamically join and leave multicast sessions at will with minimal overhead for control information and timing synchronization among participants. To accommodate this capability, NORM protocol message headers contain some common information allowing receivers to easily synchronize to senders throughout the lifetime of a reliable multicast session. NORM is designed to be self-adapting to a wide range of dynamic network conditions with little or no preconfiguration. The protocol is purposely designed to be tolerant of inaccurate timing estimations or lossy conditions that may occur in many networks including mobile and wireless. The protocol is also designed to exhibit convergence and efficient operation even in situations of heavy packet loss and large queuing or transmission delays.

Table of Contents
Table of Contents 1. Introduction and Applicability. . . . . . . . . . . . . . . . 3 1.1. NORM Delivery Service Model. . . . . . . . . . . . . . . 4 1.2. NORM Scalability . . . . . . . . . . . . . . . . . . . . 6 1.3. Environmental Requirements and Considerations. . . . . . 7 2. Architecture Definition . . . . . . . . . . . . . . . . . . . 7 2.1. Protocol Operation Overview. . . . . . . . . . . . . . . 9 2.2. Protocol Building Blocks . . . . . . . . . . . . . . . . 10 2.3. Design Tradeoffs . . . . . . . . . . . . . . . . . . . . 11 3. Conformance Statement . . . . . . . . . . . . . . . . . . . . 12 4. Message Formats . . . . . . . . . . . . . . . . . . . . . . . 13 4.1. NORM Common Message Header and Extensions. . . . . . . . 14 4.2. Sender Messages. . . . . . . . . . . . . . . . . . . . . 16 4.2.1. NORM_DATA Message . . . . . . . . . . . . . . . . 16 4.2.2. NORM_INFO Message . . . . . . . . . . . . . . . . 24 4.2.3. NORM_CMD Messages . . . . . . . . . . . . . . . . 26 4.3. Receiver Messages. . . . . . . . . . . . . . . . . . . . 43 4.3.1. NORM_NACK Message . . . . . . . . . . . . . . . . 43 4.3.2. NORM_ACK Message. . . . . . . . . . . . . . . . . 50 4.4. General Purpose Messages . . . . . . . . . . . . . . . . 52 4.4.1. NORM_REPORT Message . . . . . . . . . . . . . . . 52 5. Detailed Protocol Operation . . . . . . . . . . . . . . . . . 52 5.1. Sender Initialization and Transmission . . . . . . . . . 54 5.1.1. Object Segmentation Algorithm . . . . . . . . . . 55 5.2. Receiver Initialization and Reception. . . . . . . . . . 57 5.3. Receiver NACK Procedure. . . . . . . . . . . . . . . . . 57 5.4. Sender NACK Processing and Response. . . . . . . . . . . 59 5.4.1. Sender Repair State Aggregation . . . . . . . . . 60 5.4.2. Sender FEC Repair Transmission Strategy . . . . . 61 5.4.3. Sender NORM_CMD(SQUELCH) Generation . . . . . . . 62 5.4.4. Sender NORM_CMD(REPAIR_ADV) Generation. . . . . . 62 5.5. Additional Protocol Mechanisms . . . . . . . . . . . . . 63 5.5.1. Greatest Round-trip Time Collection . . . . . . . 63 5.5.2. NORM Congestion Control Operation . . . . . . . . 64 5.5.3. NORM Positive Acknowledgment Procedure. . . . . . 72 5.5.4. Group Size Estimate . . . . . . . . . . . . . . . 74 6. Security Considerations . . . . . . . . . . . . . . . . . . . 75 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 75 8. Suggested Use . . . . . . . . . . . . . . . . . . . . . . . . 75 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 76 10. References. . . . . . . . . . . . . . . . . . . . . . . . . . 76 10.1. Normative References. . . . . . . . . . . . . . . . . . 76 10.2. Informative References. . . . . . . . . . . . . . . . . 77 11. Authors' Addresses. . . . . . . . . . . . . . . . . . . . . . 79 Full Copyright Statement. . . . . . . . . . . . . . . . . . . 80 3