Minutes of the 16th NMRG meeting COEX Convention Center, Seoul, Korea 18 April 2004, 13:30-17:00 Participants: - J?rgen Sch?nw?lder, IUB, Germany - Aiko Pras, Univ. of Twente, The Netherlands - George Pavlou, Univ. of Surrey, UK - Radu State, Inria, France - Olivier Festor, Inria, France - Omar Cherkaoui, UQAM, Canada - James Hong, Postech, Korea - Mi-Jung Choi, Postech, Korea - Sun Mi-Yoo, , Postech, Korea - So-Jung Lee, Postech, Korea - Dong-Hyun Kim, Postech, Korea Agenda: 1. Welcome 2. NetConf Agent Toolkit YENCA (Olivier Festor, Radu State) 3. Performance Evaluation on XML-based Network Management (Mi-Jung Choi) 4. Closing NetConf Agent Toolkit: YENCA ---------------------------- Radu presented Yenca, which is a NetConf prototype developed at INRIA by Benjamin Zores, Radu and Olivier (Benjamin is a student who implemented major parts and can be contacted for technical questions). Yenca is based on the October 2003 Internet-Draft (note: the latest draft is from February), and does not include all NetConf functions. Since not all participants at this meeting were familiar with NetConf, a short overview was provided. It was made clear that NetConf originated from JunoScript, and does not include a data model to ease its standardization. If the NetConf IETF working group turns out to be successful, then work on standardized data models may be started in the IETF. It was also explained that NetConf regards data as XML documents, which may be seen as a paradigm shift compared to the variable oriented approach of SNMP. Motivations behind the development of Yenca: a) To implement and get experience with new functions that are specific for NetConf and can not be found in SNMP. b) To create a software infrastructure that can be used in future research activities, such as interoperability tests, the implementation of gateways etc. Another aspect considered during the development of Yenca was to experiment with a modular instrumentation framework and locking mechanisms. For example, there is work in progress on a Linux kernel module which can block any user level attempts to change interface configurations. The Yenca implementation uses the libxml XML library. The interface between domain specific modules and the Yenca agent passes XML fragments around. It was noted that the current implementation parses XML fragments multiple times. Since modules are dynamically loaded and run in the same address space, it should be possible to just pass the pointer to the already parsed DOM tree around. The current distribution has some small problems. The file format uses DOS line ends instead of Unix line ends, which confuses the autoconf tool-set. The Yenca framing code does not yet work and needs to be rewritten. Documentation is not yet complete. Conclusion: Although Yenca should be seen as an early prototype with inherent shortcomings (see slides for an overview), it is the first open source NetConf implementation. Others are invited to use the software and give comments. Performance evaluation of XML-based Network Management ------------------------------------------------------ Mi-Jung Choi from Postech, Korea, presented some measurement work on an SNMP to XML gateway which is related to her Ph.D. thesis. For the details of the presentations, consult the meeting web page. The SNMP to XML gateway works as follows: An XML manager sends a request to a gateway which translates this request into several requests to potentially many agents. This is different from the gateway implemented by Frank Strauss et. al. which assumes that an XML request and the corresponding response translates into several requests to a single agent. Many questions were asked during the presentation in order to understand the precise meaning of the numbers and the experimental setup. For every SNMP object, a separate SNMP message was send; the objects were not retrieved via a single combined SNMP GET or GetNext request. When talking to multiple agents, the implementation uses a sequence of serialized requests (send request, wait for response, send next request etc.) which explains some of the delay figures. The implementation uses JoeSNMP (a rather small Java SNMPv1/SNMPv2c package under GPL).