Publications
Disclaimer :
These papers are made available as a means to ensure timely dissemination of scholarly and technical work
on a non-commercial basis. Copyright and all rights therein are maintained by the authors or by other copyright holders,
notwithstanding that they have offered their works here electronically. It is understood that all persons copying
this information will adhere to the terms and constraints invoked by each author's copyright. These works may not
be reposted without the explicit permission of the copyright holder.
2006
Prototyping and Testing of GONE - GIST Overlay Networking Extension ,
Jan Demter , Bachelor thesis No. ZFI-BM-2006-37, Center for Computer Science, University of Goettingen, Germany,
ISSN 1612-6793, November 2006.
Read abstract
This thesis provides an implementation of the GIST Overlay Network Extension (GONE) and its initial performance testing. GONE is an overlay network built upon the General Internet Signaling Transport (GIST) and the Stream Control Transmission Protocol (SCTP). GIST enables GONE to automatically build an overlay along a path in an IP-network with GONE-aware routers. Each GONE-aware hop forwards traffic to the next hop via an SCTP connection, making GONE resilient to path failures due to SCTP’s failover mechanism. Protection against DoS-attacks is employed by using a per-packet capability based authentication. The thesis investigates how the functionality offered by GIST can be used in implementing a path overlay. Problems with the concept of GONE surfacing during implementation and testing are pointed out and possible solutions or hints for further research and testing are given.
PDF [756.7 kB]
2005
Performance Analysis of the TCP/IP Stack of Linux Kernel 2.6.9 ,
Jan Demter , Christian Dickmann , Xiaoming Fu , Henning Peters , Niklas Steinleitner , Technical Report No. IFI-TB-2005-03, Institute of Computer Science, University of Göttingen, Germany,
ISSN 1611-1044, April 2005.
Read abstract
This document reports the project "performance study of the TCP/IP stack for the Linux kernel" which we performed during the practical course Computer Networks in winter semester 2004/05, including its design, implementation and performance results. We analysed the packet processing time traversing each layer of the Linux kernel 2.6.9 TCP/IP stack (socket, TCP/UDP, IP and Ethernet) and the influence of multi-threading and different packet sizes. The design is based on the idea of inserting probing points via hooks in the kernel code and export timing data to a userspace application. A packet generator and analysis tools were also developed. The results demonstrate a number of key concepts in TCP/IP networking, such as layering, user-system interface, connection versus datagram modes, processing routines and their overhead in different layers. Some preliminary results reveal the system has its bottlenecks in different situations, and our tools released under GPL-license have been designed in such a way that allows easy extensibility for other networking diagnostics purposes.
PDF [246.1 kB]