Active Networks and Active Network Management: A Proactive Management Framework / Edition 1

by Stephen F. Bush, Amit B. Kulkarni

Overview

Active networking is an exciting new paradigm in digital networking that has the potential to revolutionize the manner in which communication takes place. It is an emerging technology, one in which new ideas are constantly being formulated and new topics of research are springing up even as this book is being written. This technology is very likely to appeal to a broad spectrum of users from academia and industry. Therefore, this book was written in a way that enables all these groups to understand the impact of active networking in their sphere of interest. Information services managers, network administrators, and e-commerce developers would like to know the potential benefits of the new technology to their businesses, networks, and applications. The book introduces the basic active networking paradigm and its potential impacts on the future of information handling in general and on communications in particular. This is useful for forward-looking businesses that wish to actively participate in the development of active networks and ensure a head start in the integration of the technology in their future products, be they applications or networks. Areas in which active networking is likely to make significant impact are identified, and the reader is pointed to any related ongoing research efforts in the area.
The book also provides a deeper insight into the active networking model for students and researchers, who seek challenging topics that define or extend frontiers of the technology. It describes basic components of the model, explains some of the terms used by the active networking community, and provides the reader with taxonomy of the research being conducted at the time this book was written. Current efforts are classified based on typical research areas such as mobility, security, and management. The intent is to introduce the serious reader to the background regarding some of the models adopted by the community, to outline outstanding issues concerning active networking, and to provide a snapshot of the fast-changing landscape in active networking research. Management is a very important issue in active networks because of its open nature. The latter half of the book explains the architectural concepts of a model for managing active networks and the motivation for a reference model that addresses limitations of the current network management framework by leveraging the powerful features of active networking to develop an integrated framework. It also describes a novel application enabled by active network technology called the Active Virtual Network Management Prediction (AVNMP) algorithm. AVNMP is a pro-active management system; in other words, it provides the ability to solve a potential problem before it impacts the system by modeling network devices within the network itself and running that model ahead of real time.

Product Details

ISBN-13:	9780306465604
Publisher:	Springer US
Publication date:	05/31/2001
Series:	Network and Systems Management
Edition description:	2001
Pages:	196
Product dimensions:	6.10(w) x 9.25(h) x 0.02(d)

About the Author

Stephen F. Bush is a Computer Scientist at General Electric Research and Development in Niskayuna, New York. Dr. Bush conducts research in advanced networking concepts. He has numerous patents pending in the area of network security and vulnerability analysis and provisional patents for active networks in both terrestrial and spacebased communication systems. Dr. Bush received his B.S. in Electrical and Computer Engineering from Carnegie Mellon University and M.S. in Computer Science from Cleveland State University. Before joining General Electric Research and Development, Dr. Bush was a researcher at the Information and Telecommunications Technologies Center at the University of Kansas where he contributed to the DARPA Rapidly Deployable Radio Networks Project. Dr. Bush completed his Ph.D. research at the University of Kansas where he received a Strobel Scholarship Award. He received the award of Achievement for Professional Initiative and Performance for his work as Technical Project Leader at General Electric Information Systems in the areas of network management and control while pursuing his Ph.D.

Amit B. Kulkarni is a Computer Scientist at General Electric Research and Development in Niskayuna, New York. Before joining GE Corporate Research & Development, Dr. Kulkarni was a researcher at the Information and Telecommunications Technology Center at the University of Kansas where he worked on the DARPA Multidimensional Applications and Gigabit Inter-network Consortium (MAGIC-II) project. He received his B.S. in Electronics and Telecommunications Engineering from the University of Pune, India, and his M.S. and Ph.D. from the University of Kansas.

Read an Excerpt

2: Properties of Active Networks

Active networking provides a programmable infrastructure using a well-defined structure for packets that contain general-purpose program code and a uniform standardized execution platform at the nodes of the network. This chapter gives the reader an overview of the basic model of an active network. It describes basic components and introduces common terminology. It also describes the efforts of the active networking community to develop an active network backbone for collaborative research. Finally, it discusses a few popular execution environments. This discussion involves tools that were available in the spring of 2000 and it will be useful for someone evaluating active network prototypes for their own research and applications.

2.1 Active Networking Model

Future applications will have to combat a myriad of network bandwidths ranging from a few kilobits per second to gigabits per second. Applications have to deliver information to users over a variety of access technologies from optic fiber to phone lines to wireless. Applications will need to be network-aware to adapt to the constraints of the underlying networking hardware. The current networking model has severe limitations that prevent it from meeting the demanding needs of emerging and future applications and allowing users "anytime, anywhere" access to information.

However, traditional networking protocols were built for largely non-real time data with very few burst requirements. The protocol stack at a network node is fixed and the network nodes only manipulate protocols up to the network layer. New protocols such as RTP and HTTP enable the network to transport other types of application data like real time and multimedia data. Such protocols cater to specific demands of the application data. Transporting those new data types over a legacy network requires the transformation of the data of a new type into data of a type carried by the network. However, transforming the data to fit legacy protocol requirements prevents one from understanding the transformed protocol. For example, embedding an MPEG frame in MIME format prevents one from easily recognizing an I, P or B frame. This prevents the network from taking suitable action on the MPEG frame during times of congestion. If information about the frame (e.g., the type of the frame, whether I, P or B) is not converted into MIME but the frame itself is converted, then both the goals of encoding and congestion control are satisfied.

Traditional protocol frameworks use layering as a composition mechanism. Protocols in one layer of the stack cannot guarantee anything about the properties of the layers underneath it. Each protocol layer is treated like a black box, and there is no mechanism to identify whether functional redundancies occur in the stack. Sometimes, protocols in different layers of the same stack need to share information. For example, TCP calculates a checksum over the TCP message and the IP header. But this action violates modularity of the layering model because the TCP module needs information from the IP header that it gets by directly accessing the IP header. Furthermore, layering hides functionality, which can introduce redundancy in the protocol stack. Introducing new protocols in the current infrastructure is a difficult and time-consuming process. A committee has to agree on the definition of a new protocol. This involves agreeing on a structure, states, algorithms, and functions for the protocol. All these issues require a consensus agreement on the part of a committee that standardizes the protocol. Experience has shown that the standardization is a time-consuming process. The time from conceptualization of a protocol to its actual deployment in the network is usually a matter of years. For example, work on the design of the Internet Protocol version 6 (IPv6) was initially started in 1995, but the protocol has still not found widespread deployment. Once the standardization process is completed, it is followed by identical implementations of the protocol in all devices. However, variations in the implementation by different network hardware vendors causes problems for interoperability. Vendor implementation of a protocol may differ if the vendors provide value-added features in their device or if they tweak the implementation to exploit hardware-specific features.

Another issue that vendors have to deal with is backward compatibility. A revision of a protocol may need to change the positions of the bits in the header of the protocol to accommodate more information. However, network devices upgraded with the new protocol still have to support data that conforms to the earlier revision. For example, the address field in the Internet Protocol (version 4) is 32 bits, as defined in the standards document. This implies that the protocol (and hence the network) supports a maximum of 2³² addresses. The tremendous growth of the Internet and the introduction of Internetcapable devices indicates that we are likely to run out of IP numbers in a very short time. Increasing the length of the address field in the IP header is not a solution to this problem because implementing the revised protocol is a formidable task. Increasing the length of the address field affects the positions of the succeeding fields in the protocol header as the bits are shifted by the appropriate number of positions. All software related to IP layer processing relies on the fields being in their correct positions, and therefore all existing communication software would have to be rewritten to accommodate the change. This requires updating tens of thousands of existing routers and switches that implement IPv4 with the new protocol software.

Active networking provides a flexible, programmable model of networking that addresses the concerns and limitations described above. In an active networking paradigm, the nodes of the network provide execution environments that allow execution of code dynamically loaded over the network. Thus, instead of standardizing individual protocols, the nodes of the network present a standardized execution platform for the codecarrying packets. This approach eliminates the need for network-wide standardization of individual protocols. New protocols and services can be rapidly introduced in the network. Standardizing the execution platform implies that the format of the code inside the packets is also agreed upon. But users and developers can code their own custom protocols in the packets. The code may describe a new protocol for transporting video packets or it may implement a custom routing algorithm for packets belonging to an application. The ability to introduce custom protocols breaks down barriers to innovation and enables developers to customize network resources to effectively meet their application's needs. Standardizing the execution environment enables new protocols to be designed, developed and deployed rapidly and effortlessly. The protocol designer develops the protocol for the standardized execution environment and injects it into the network nodes for immediate deployment. This eliminates the need for a standards committee to design the protocol, for hardware vendors to implement it in their network devices, and for service providers to deploy the new devices in their networks. Application designers can write custom code that performs custom computation on the packets belonging to the application. This customizes network resources to meet the immediate requirements of the application. Thus the programmable interface provided by active networking enables applications to interact with the network and adapt to underlying network characteristics. Note that active networks differ from efforts underway in programmable networks. Active networks carry executable within packets while programmable networks focus on a standard programming interface for network control.

2.2 Active Network Operation

Custom code is injected in the network in one of two ways. One approach is to download the code to the nodes separately from the data packets. The downloaded code carries the computation for some or all of the data packets flowing through the node. The code is invoked when the intended data packets reach the node. This is known as the discrete approach (da Silva et al., 1988; Huber and Toutain, 1997). The other approach is the capsule or integrated approach (Wetherall et al., 1999; Kulkarni et al., 1998). In this approach, packets carry the computation as well as the data. As the packets flow through the nodes, the custom code is installed at some or all the nodes in the network. These packets are called capsules or SmartPackets. These are the basic unit of communication in an active network. Applications inject SmartPackets in the network and active nodes process the code inside the SmartPackets. A hybrid of the discrete and integrated approaches is PLAN (Hicks et al., 1999). The nodes of an active network, called active nodes, provide the platform for SmartPackets to execute the custom code. Active nodes participate in the customization of the network by the applications instead of passively switching or routing data packets through the network....

Table of Contents

to Active Networking.- Properties of Active Networks.- Active Network Architecture.- Architectural Framework.- Management Reference Model.- AVNMP.- AVNMP Architecture.- AVNMP Operational Examples.- AVNMP Algorithm Description.- Algorithm Analysis.- Aspects of AVNMP Performance.