ABSTRACT
The ARPANET routing metric was revised in July 1987, resulting in substantial performance improvements, especially in terms of user delay and effective network capacity. These revisions only affect the individual link costs (or metrics) on which the PSN (packet switching node) bases its routing decisions. They do not affect the SPF (“shortest path first”) algorithm employed to compute routes (installed in May 1979). The previous link metric was packet delay averaged over a ten second interval, which performed effectively under light-to-moderate traffic conditions. However, in heavily loaded networks it led to routing instabilities and wasted link and processor bandwidth.
The revised metric constitutes a move away from the strict delay metric: it acts similar to a delay-based metric under lightly loads and to a capacity-based metric under heavy loads. It will not always result in shortest-delay paths. Since the delay metric produced shortest-delay paths only under conditions of light loading, the revised metric involves giving up the guarantee of shortest-delay paths under light traffic conditions for the sake of vastly improved performance under heavy traffic conditions.
- 1.ARPANET Performance Analysis Report. Quarterly Report 11, BBN, Aug. 1987.Google Scholar
- 2.MILNET Routing Improvements: Measurements and Analysis of the $PF Metric Patch. BBN Report 6719, BBN, Feb. 1988.Google Scholar
- 3.D. P. Bertsekas. Dynamic Behavior of Shortest Path Routing Algorithms for Communication Networks. IEEE Transactions on Automatic Control, AC-27:60- 74, Feb. 1982.Google ScholarCross Ref
- 4.E. W. Dijkstra. A Note on Two Problems in Connection with Graphs. Numerische Mathematik, 1:269- 271, 1959.Google ScholarDigital Library
- 5.R. Gallager and D. Bertsekas. Data Networks. Prentice-Hail, 1987. Google ScholarDigital Library
- 6.V. Haimo, M. Gardner, I. I_x>obeek, and M. Frishkopf. Multi-Path Routing: Modeling and Simulation. BBN Report 6363, BBN, Sep. 1986.Google Scholar
- 7.A. Khanna. Short-Term Modifications to Routing and Congestion Control. BBN Report 6714, BBN, Feb. 1988.Google Scholar
- 8.J. M. McQuillan, G. Falk, and I. Richer. A Review of the Development and Performance of the ARPANET Routing Algorithm. IEEE Transactions on Communications, 1802-1811, De~c. 1978.Google Scholar
- 9.J. M. McQuillan, I. Richer, and E. C. Rosen. ARPANET Routing Algorithm Improvements: First Semiannual Technical Report. BBN Report 3803, BBN, Apr. 1978.Google ScholarCross Ref
- 10.J. M. McQuillan, I. Richer, and E. C. Rosen. The New Routing Algorithm for the ARPANET. IEEE Transactions on Communications, 711-719, May 1980.Google Scholar
- 11.J.M. McQuillan, I. Richer, E. C. Rosen, and D. P. Bertsekas. ARPANET Routing Algorithm Improvements: 2nd Semiannual Technical Report. BBN Report 3940, BBN, Oct. 1978.Google ScholarCross Ref
- 12.J.M. McQuillan, I. Richer, E. C. Rosen, and J. G. Herman. ARPANET Routing Algorithm Improvements: 3rd Semiannual Technical Report. BBN Report 3940, BBN, Oct. 1978.Google ScholarCross Ref
- 13.E. C. Rosen. The Updating Protocol of ARPANET's New Routing Algorithm. Computer Networks, 4:11- 19, Feb. 1980.Google Scholar
- 14.J. A. Zinky, A. Khanna, and G. Vichniac. Performance of the Revised Routing Metric for ARPANET and MILNET. Submitted to MILCOM 89, March 1989.Google Scholar
Index Terms
- The revised ARPANET routing metric
Recommendations
An overview of the new routing algorithm for the ARPANET
SIGCOMM '79: Proceedings of the sixth symposium on Data communicationsThe original routing algorithm of the ARPANET, in service for over a decade, has recently been removed from the ARPANET and replaced with a new and different algorithm. Although the new algorithm, like the old, is a distributed, adaptive routing ...
The revised ARPANET routing metric
The ARPANET routing metric was revised in July 1987, resulting in substantial performance improvements, especially in terms of user delay and effective network capacity. These revisions only affect the individual link costs (or metrics) on which the PSN ...
An overview of the new routing algorithm for the ARPANET
Special twenty-fifth anniversary issue. Highlights from 25 years of the Computer Communication ReviewThe original routing algorithm of the ARPANET, in service for over a decade, has recently been removed from the ARPANET and replaced with a new and different algorithm. Although the new algorithm, like the old, is a distributed, adaptive routing ...
Comments