/nsfnet/linkletter/linkletter.881031 Vol. 1 No. 11 31 October 1988 T H E L I N K L E T T E R The Merit/NSFNET Backbone Project NEW BACKBONE DOUBLES TRAFFIC COUNTS With September over, the re-engineered backbone has been in full production for three months. Both traffic and network connections have increased dramatically in this period. The number of campus networks with primary connections to NSFNET through the mid-level networks has gone from 173 at the beginning of July to 292 by the end of September. At present, all but a few of the campuses that are expected to be connected to the new backbone are online currently, and many additional networks have also been added to reach the present total. Packet counts indicate traffic has more than doubled that carried by the old backbone. As shown in the figure below, traffic has taken a dramatic leap as the backbone expanded from the six supercomputer centers to the present thirteen nodes. The table shows the numbers for packet counts on the new backbone during August and September 1988. (July statistics are not available.) September was over a third higher than August indicating rapid increases in usage of the new backbone. The packet counts are taken at the token ring interface to the E-PSP in each Nodal Switching Subsystem (NSS) via SGMP. The hourly counts are collected and stored in a database on the Information Services host machine. As this database is developed, it will be accessible to interested users. In addition, databases showing network connections and addresses are also nearing completion. Watch for an announcement in next month's Link Letter. Packets in Packets out Aug. 202,641,056 194,041,532 Sept. 314,675,718 304,171,588 % increase 35.6% 36.2% * * * FROM HERE TO FRANCE: NSF AND NASA JOIN FORCES TO REACH OVERSEAS The National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA) have joined forces to provide an international data communications link to France that is accessed through NSFNET. This overseas connection, which uses an International Satellite Link provided by MCI, joins Princeton University and the Institut National de Recherche en Informatique et Automatique (INRIA), making possible access to SIMBAD, an astronomy database. This database, more formally the Set of Identifications, Measurements and Bibliography of Astronomical Data or SIMBAD, runs on a host machine located near Paris and contains nearly all known references to celestial objects dating back to 1950. Through this database, a researcher can obtain bibliographic citations relating to a specific star or other object by name or reference number, as well as general statistics about it. A small staff keeps SIMBAD up to date by entering references from astronomical and other scientific journals published throughout the world. The link between the U.S. and France has been tested during demonstrations several times throughout the summer, including at a meeting of the Library and Information Services Association in late July and during the International Astronomical Union's General Assembly in early August. MCI also demonstrated the database at its Executive Communication Seminar in early October. Beginning later this year, the international link will be maintained permanently for use by NSF and NASA scientific communities. Presently, the link provides a connection from the NSFNET to an application level gateway at INRIA. This gateway converts Telnet, the Internet terminal-to-host protocol, to the XXX protocols used for this purpose in Europe, thereby allowing scientists in the United States to log in to a machine in France which provides the SIMBAD service. In the future, the link will also be used to connect the NSFNET to French networks utilizing the Internet protocols. Experiments with a gateway between the OSI connection-oriented network layer, which will be used in Europe, and the OSI connectionless network layer to be used in the U.S. will be conducted via this link. MCI's continuing commitment to NSFNET includes exploring the potential for other innovative data communication links required by the scientific and research communities. By making NSFNET and related activities an executive level project within MCI, such research needs are given high priority by the company. The project is funded by the NSF and NASA in the U.S. and by INRIA in France. It is being directed by Lawrence Landweber of the University of Wisconsin and Christian Huitema of INRIA. -Contributions to this article made by Brad Bishop, MCI, and Lawrence Landweber, University of Wisconsin. * * * IBM MOVES FORWARD WITH NETWORK PLANNING It has been satisfying over the last three months to observe the performance of the new NSFNET and to watch the usage grow. This has served as an extra stimulus to move forward with the planning for continued enhancements to the network. In November, IBM, in cooperation with its project partners, shall finalize plans for network improvements to be implemented starting in the 4th quarter 1988 through the 4th quarter 1989. Consensus thinking currently favors a regular, incremental delivery of these new functions. This plan features enhancements to bandwidth management, network control capabilities, EGP 3 and SNMP/CMOT developments, and performance capacity enhancements. On October 20, IBM presented options for the plan to the NSFNET management team and is now continuing in the evaluation and feedback stage. Some objectives for fourth quarter 1988 and early 1989 include: --Significantly increasing the rate at which each Packet Switching Processor can drive the IDNX T1 Resource Manager. --Providing a substantially higher performance Ethernet Adapter for the regional network gateway attachments to the NSFNET. These are aimed at improving speeds on the NSSs needed to move toward T3 speeds in the future. In the area of network management, a basis for future progress has been established with the installation of IBM's Information Management, NetView, Netview/PC, and a Simple Gateway Monitoring Protocol implementation. Two-way mapping of some TCP/IP network management functions and NetView capabilities were demonstrated at the Interop '88 conference in September. This is believed to be the first synergy between TCP/IP and NetView. A future emphasis will be to upgrade the SGMP protocols to the recently evolved SNMP and/or CMIP levels. IBM Service's Electronic Customer Communication Option (ECCO) system has been installed at the NOC. This allows service calls to the proper IBM customer engineers across the country to be placed quickly and efficiently from a terminal in the NOC. Early reports indicate that the easy-to-use ECCO has been quite effective in streamlining the service process at the NOC. The Merit/NSFNET project team looks forward to continuing support from the user community as the new NSFNET moves into the future. * * * PHYSICAL AND LOGICAL TOPOLOGIES: STUDYING PATTERNS FOR FUTURE DEVELOPMENT The NSFNET backbone design described in Merit's proposal uses a hybrid of circuit and packet switching technologies. The principal reason for this design is to gain the ability to dynamically allocate bandwidth in a datagram network, as well as create and change paths (i.e., logical topology) according to the varying needs at any given time. Dynamic bandwidth allocation is scheduled to play a more important role in later phases of the five-year project as we work with MCI to directly access their Digital Reconfiguration Services (DRS). The phases for this development are described in Merit's NSFNET backbone proposal submitted to the National Science Foundation. At present, the Phase I backbone has T1 circuits terminated by Integrated Digital Network Exchanges (IDNX) equipment. The IDNX allows bandwidth allocation and logical topology creation to a more limited extent than will be possible in Phase 1A scheduled for mid- 1989. Currently, IDNX technology takes the end-to-end T1 circuits and allocates bandwidth on them while creating a logical topology which overlays the physical circuits. A diagram of the physical circuits is shown in Figure 1. For the initial logical topology, we had several goals: --provide more than one logical connection to any given node --have a diameter of three hops or less between nodes in the backbone --provide equitable access to each node In particular, embodied in the last point is the notion of fairness. Merit's intention is to provide fair and equal access to each node during the first phase of backbone operation. The specific combination of thirteen mid-level nodes now part of NSFNET establishes a pattern of network usage and traffic flow that is quite different from that of the old backbone. Initial bandwidth allocation was done without the assistance of traffic and performance data to assist in the decision-making process. To provide for equitable access during Phase I the existing T1 circuits are divided into three logical sub-T1 circuits at each node by using the capabilities of the IDNXs. This results in the logical topology illustrated in Figure 2. Because fitting three 448 Kbps circuits per node into the overall physical network resulted in some excess bandwidth, three additional logical links were implemented (visible as shaded links). As operation continues, we are using our knowledge of NSFNET's dynamics which will be critical to later phases of the project. Ongoing discussions between Merit, NSF, and the regionals will continue to play a role in the way topologies develop and dynamic reconfiguration is implemented. Data on usage and traffic flow for the first three months are already showing the complex patterns that the new services will need to handle in order to maximize the network's potential. * * * FROM WORKING PAPERS TO WORKING PEERS WITH EGP The Exterior Gateway Protocol (EGP) provides the routing interface between the NSFNET backbone and the mid-level networks. Each Nodal Switching Subsystem (NSS) uses EGP to exchange reachability information with one or more gateways maintained by the associated mid-level network. Routing data passes back and forth between the backbone and the mid-levels via EGP. Making EGP a working protocol within NSFNET required much advance planning and development work, not only by Merit and its research partners, but also by the mid-levels and gateway vendors. The application of EGP for the interface to mid-level networks requires that mid-level gateways conform to specific guidelines. These are described in two papers issued in the spring of 1988, "EGP and policy routing in the new NSFNET backbone" by Jacob Rekhter, T. J. Watson Research Center, IBM Corporation, and "The NSFNET routing architecture" by Hans-Werner Braun, Merit/NSFNET Internet Engineering. (These papers are available via FTP from the NSFNET Information Services host machine.) When Merit first proposed this implementation, the guidelines made demands on gateway software that were not then implemented in existing vendor products. Vendor cooperation in developing and implementing needed changes has made the combination of the NSFNET backbone and the attached mid-level networks work well. In particular, Cisco and Proteon modified and augmented their EGP implementations to meet the needs of the NSFNET. These vendors made early versions of their updated software available to Merit for testing prior to deployment in the mid-level networks and were very responsive to problems which arose. Vendors continue to work with Merit to provide more functionality for the interconnection. Further work was also done by the "gated" development team at the Cornell University Theory Center. They worked directly with IBM on the NSS software implementation of EGP, as well as providing valuable assistance in terms of conceptualizing requirements and designing the routing interface between the NSS and mid-level networks. The regionals also assisted in meeting the new guidelines by altering their configurations and utilizing Autonomous Systems (AS) numbers. The cooperative spirit of EGP development for NSFNET by the vendors and regionals has been extremely important to the success of the new backbone. Merit is pleased with the cooperation shown by this project and recognizes that the growing team spirit within the NSFNET community will be a major factor in future development efforts. * * * LETTERS Eric M. Aupperle Director, Merit Computer Network Dear Eric: The NSF supercomputer centers are widely used by the nation's science and engineering community via networking and telecommunication technology. In fact, the need for access to these centers provided the initial impetus for the NSFNET. So, we have watched with intense interest as Merit Corporation, IBM, and MCI assumed the management of NSFNET and set in motion activities to upgrade it. The purpose of this letter is to commend the work that Merit and its partners have accomplished over the past year. This was a formidable task that was completed expeditiously and professionally. We understand that this effort required commitments that went substantially beyond the call of duty and we appreciate your having made them. The upgrade is performing well and is a good first step in providing state-of-the-art capability. Because of it, the rate of scientific progress in the United States will be accelerated over the next couple of years. Thanks for a job well done and we look forward to working with Merit in the future. Jim Bottum, National Center for Supercomputer Applications Bill Buzbee, Scientific Computing Division, NCAR Sid Karin, San Diego Supercomputing Center Doyle Knight, John von Neumann Center Larry Lee, Theory Center, Cornell University Mike Levine, Pittsburgh Supercomputing Center Ralph Roskies, Pittsburgh Supercomputing Center * * * The Link Letter is published by the Merit Computer Network/NSFNET Information Services, 1075 Beal, Ann Arbor, Michigan 48109-2112. Anyone interested in receiving the electronic version of The Link Letter should send a message to: NSFNET-Linkletter- Request@merit.edu For more information, reach us at NSFNET-info@merit.edu or by calling 1-800-66-MERIT. We welcome suggestions and contributions. IS Staff: Elise Gerich, William Hart, Ellen Hoffman, Janise Honeyman, Laura Kelleher, Rick Schmalgemeier, Andrew Simms, Jim Sweeton. Jo Ann Ward. * * * * * * *