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Title Date Added Company

Real Stateful TCP Packet Filtering in IP Filter 2007-09-26 Administration and Network Engineering

IP Filter is an Open Source packet filtering engine that is available for a number of operating systems, including Solaris and FreeBSD, Open-BSD and NetBSD. IP Filter comes with so-called stateful packet filtering. In the case of TCP, the state engine not only inspects the presence of ACK flags, or looks at source and destination ports, but it includes sequence numbers and window sizes in its decision to pass or block packets. This greatly reduces the window of opportunity for malicious packets to be passed through the packet filter, even in the case when source and destination ports and addresses are known.

Enhancing TCP Over HSDPA by Cross-Layer Signalling 2007-09-24 University of California

A comprehensive performance evaluation of a cross-layer solution to increase users' downlink data rates over HSDPA is provided. The solution consists of a proxy entity between a server and the Radio Network Controller, and cross-layer signaling from the base station to the proxy. The performance of the solution is evaluated though a detailed ns-2 simulator environment, which includes all HSDPA features, as well as some existing TCP enhancing protocols widely adopted for internet traffic over wireless links. Numerical results show that the proxy significantly increases the users' throughput, while also improving the utilization of the radio resources.

Latency Evaluation of Networking Mechanisms for Game Traffic 2007-09-20 University of Oslo

Large improvements in computer technology allow thousands of users to concurrently interact in a virtual game. Due to this development, the body of work analyzing game traffic has grown considerably in the recent past. However, little work has been done to examine and compare networking techniques with respect to meeting the stringent latency requirements that are common for networked games. Most interactive games need response times between 100 and 1000 ms depending on the game genre. This paper evaluates different techniques for delivering packets in a timely manner.

Implementation and Evaluation of Late Data Choice for TCP in Linux 2007-09-11 University of Oslo

Real-time delivery of time-dependent data over the Internet is challenging. UDP has often been used to transport data in a timely manner, but its lack of congestion control is often criticized. This criticism is a reason that the vast majority of applications today use TCP. The downside of this is that TCP has problems with the timely delivery of data. A transport protocol that adds congestion control to an otherwise UDP-like behaviour is DCCP. For this protocol, late data choice (LDC)] has been proposed to allow adaptive applications control over data packets up to the actual transmission time. It was found that, however, those application developers appreciate other TCP features as well, such as its reliability.

Bridging the Gap between TDM and IP for Enterprise Businesses 2007-09-09 Level 3 Communications

Level 3 Communications' TDM-to-IP migration strategy focuses on bridging the gap for companies that want to retain their legacy telephone systems, invest in IP and keep their business running efficiently today. There are benefits in moving to IP, such as reducing communications costs and increasing feature flexibility.

Tags: Network Design

An Extension of the Square Root Law of TCP 2007-09-05 Georgia Institute of Technology

Using probabilistic scaling methods, the square root law of TCP to schemes is extended which may not be of the AIMD type. The results offer insight in the relationship between throughput and loss rate, and the time scale on which losses take place. Similar results are shown to hold in scenarios where dependencies between losses occur.

Improving Testing Capability of Interoperability for Link-11 by Building a Gateway for a TCP/IP Network 2007-09-04 University of Arizona

Link-11 is a tactical digital communication network standard deployed in military platforms now for several decades. The standard employs the digital modulation technique Differential Quadrature Phase Shift Keying (DQPSK) to encode formatted binary messages (M-series messages) onto an audio channel, which are then modulated and transmitted over a radio communications network. Testing of the various systems that use this communications network requires either a fully operational RF network or exchange of the audio-encoded data over a voice channel. An alternative is to send and receive over an IP network, by encoding and decoding the audio from a Data Terminal Set (DTS) that is part of the normal operational equipment.

Tags: Gateways - Hubs

TFRC Veno: An Enhancement of TCP Friendly Rate Control Over Wired/Wireless Networks 2007-09-02 Nanyang Technological University

TFRC is a TCP-Friendly Rate Control protocol based on TCP Reno's throughput equation. It is designed to provide optimal service for unicast multimedia flow operating in the wired Internet environment. However, in wireless networks, TFRC, same as TCP Reno, suffers significant performance degradation. This paper proposes to make use of a more advanced equation to enhance TFRC over wireless networks. After incorporating this equation into TFRC, two achievements are obtained: this enhanced TFRC has a significant throughput improvement; it is shown that in wireless networks with 10% loss rate, it can obtain 300% improvement over the original TFRC; this enhanced TFRC inherits the desirable features of TFRC, namely good fairness, nice TCP-friendliness and smoothness of sending rate.

Tags: Mobile - Wireless Communications

TCP's Protocol Radius: The Distance Where Timers Prevent Communication 2007-09-01 Cisco Systems

This paper examines how the design of the Transmission Control Protocol (TCP) implicitly presumes a limited range of path delays and distances between communicating endpoints. It shows that TCP is less suited to larger delays due to the interaction of various timers present in TCP implementations that limit performance and, eventually, the ability to communicate at all as distances increase. The resulting performance and protocol radius metrics that the authors establish by simulation indicate how the TCP protocol performs with increasing distance radius between two communicating nodes, and show the boundaries where the protocol undergoes visible performance changes. This allows assessing the suitability of TCP for long-delay communication, including for deep-space links.

Tags: Mobile - Wireless Communications

TCP Testing - Preventing Global Internet Warming 2007-09-01 National University of Ireland, Maynooth

Do the new TCP congestion control algorithms and other changes have unfairness that could lead to congestion collapse? Testing multiple flows using applications (rsync and ftp) shows some unfairness exists when the bottleneck queue is large; but the new algorithms are no more unfair than standard TCP. The Transmission Control Protocol (TCP) is responsible for maintaining both the reliability of individual connections, and the stability of the overall Internet.

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Title	Date Added	Company
Real Stateful TCP Packet Filtering in IP Filter	2007-09-26	Administration and Network Engineering
IP Filter is an Open Source packet filtering engine that is available for a number of operating systems, including Solaris and FreeBSD, Open-BSD and NetBSD. IP Filter comes with so-called stateful packet filtering. In the case of TCP, the state engine not only inspects the presence of ACK flags, or looks at source and destination ports, but it includes sequence numbers and window sizes in its decision to pass or block packets. This greatly reduces the window of opportunity for malicious packets to be passed through the packet filter, even in the case when source and destination ports and addresses are known.
Enhancing TCP Over HSDPA by Cross-Layer Signalling	2007-09-24	University of California
A comprehensive performance evaluation of a cross-layer solution to increase users' downlink data rates over HSDPA is provided. The solution consists of a proxy entity between a server and the Radio Network Controller, and cross-layer signaling from the base station to the proxy. The performance of the solution is evaluated though a detailed ns-2 simulator environment, which includes all HSDPA features, as well as some existing TCP enhancing protocols widely adopted for internet traffic over wireless links. Numerical results show that the proxy significantly increases the users' throughput, while also improving the utilization of the radio resources.
Latency Evaluation of Networking Mechanisms for Game Traffic	2007-09-20	University of Oslo
Large improvements in computer technology allow thousands of users to concurrently interact in a virtual game. Due to this development, the body of work analyzing game traffic has grown considerably in the recent past. However, little work has been done to examine and compare networking techniques with respect to meeting the stringent latency requirements that are common for networked games. Most interactive games need response times between 100 and 1000 ms depending on the game genre. This paper evaluates different techniques for delivering packets in a timely manner.
Implementation and Evaluation of Late Data Choice for TCP in Linux	2007-09-11	University of Oslo
Real-time delivery of time-dependent data over the Internet is challenging. UDP has often been used to transport data in a timely manner, but its lack of congestion control is often criticized. This criticism is a reason that the vast majority of applications today use TCP. The downside of this is that TCP has problems with the timely delivery of data. A transport protocol that adds congestion control to an otherwise UDP-like behaviour is DCCP. For this protocol, late data choice (LDC)] has been proposed to allow adaptive applications control over data packets up to the actual transmission time. It was found that, however, those application developers appreciate other TCP features as well, such as its reliability.
Bridging the Gap between TDM and IP for Enterprise Businesses	2007-09-09	Level 3 Communications
Level 3 Communications' TDM-to-IP migration strategy focuses on bridging the gap for companies that want to retain their legacy telephone systems, invest in IP and keep their business running efficiently today. There are benefits in moving to IP, such as reducing communications costs and increasing feature flexibility. Tags: Network Design
An Extension of the Square Root Law of TCP	2007-09-05	Georgia Institute of Technology
Using probabilistic scaling methods, the square root law of TCP to schemes is extended which may not be of the AIMD type. The results offer insight in the relationship between throughput and loss rate, and the time scale on which losses take place. Similar results are shown to hold in scenarios where dependencies between losses occur.
Improving Testing Capability of Interoperability for Link-11 by Building a Gateway for a TCP/IP Network	2007-09-04	University of Arizona
Link-11 is a tactical digital communication network standard deployed in military platforms now for several decades. The standard employs the digital modulation technique Differential Quadrature Phase Shift Keying (DQPSK) to encode formatted binary messages (M-series messages) onto an audio channel, which are then modulated and transmitted over a radio communications network. Testing of the various systems that use this communications network requires either a fully operational RF network or exchange of the audio-encoded data over a voice channel. An alternative is to send and receive over an IP network, by encoding and decoding the audio from a Data Terminal Set (DTS) that is part of the normal operational equipment. Tags: Gateways - Hubs
TFRC Veno: An Enhancement of TCP Friendly Rate Control Over Wired/Wireless Networks	2007-09-02	Nanyang Technological University
TFRC is a TCP-Friendly Rate Control protocol based on TCP Reno's throughput equation. It is designed to provide optimal service for unicast multimedia flow operating in the wired Internet environment. However, in wireless networks, TFRC, same as TCP Reno, suffers significant performance degradation. This paper proposes to make use of a more advanced equation to enhance TFRC over wireless networks. After incorporating this equation into TFRC, two achievements are obtained: this enhanced TFRC has a significant throughput improvement; it is shown that in wireless networks with 10% loss rate, it can obtain 300% improvement over the original TFRC; this enhanced TFRC inherits the desirable features of TFRC, namely good fairness, nice TCP-friendliness and smoothness of sending rate. Tags: Mobile - Wireless Communications
TCP's Protocol Radius: The Distance Where Timers Prevent Communication	2007-09-01	Cisco Systems
This paper examines how the design of the Transmission Control Protocol (TCP) implicitly presumes a limited range of path delays and distances between communicating endpoints. It shows that TCP is less suited to larger delays due to the interaction of various timers present in TCP implementations that limit performance and, eventually, the ability to communicate at all as distances increase. The resulting performance and protocol radius metrics that the authors establish by simulation indicate how the TCP protocol performs with increasing distance radius between two communicating nodes, and show the boundaries where the protocol undergoes visible performance changes. This allows assessing the suitability of TCP for long-delay communication, including for deep-space links. Tags: Mobile - Wireless Communications
TCP Testing - Preventing Global Internet Warming	2007-09-01	National University of Ireland, Maynooth
Do the new TCP congestion control algorithms and other changes have unfairness that could lead to congestion collapse? Testing multiple flows using applications (rsync and ftp) shows some unfairness exists when the bottleneck queue is large; but the new algorithms are no more unfair than standard TCP. The Transmission Control Protocol (TCP) is responsible for maintaining both the reliability of individual connections, and the stability of the overall Internet.