Home   >   CSC-OpenAccess Library   >    Manuscript Information
Full Text Available

This is an Open Access publication published under CSC-OpenAccess Policy.
Publications from CSC-OpenAccess Library are being accessed from over 74 countries worldwide.
A Critical Note On Ring Flushing
Syed Muhammad Atif
Pages - 87 - 102     |    Revised - 01-05-2011     |    Published - 31-05-2011
Volume - 3   Issue - 2    |    Publication Date - May / June 2011  Table of Contents
Ring Flushing, Frame Flooding, Network Scalability, RSTP Compatibility
Rapid Spanning Tree Protocol enable switches to flood incoming frame with broadcast or unknown unicast destination address even in switched Ethernet networks having redundant links. It also allows switches to secretly learn location of connected devices in such networks. However some of those learnt location may become stale if a topology change is detected by RSTP and need to be flushed by switches in the network. It is find that standard address flushing technique of RSTP flushes too many addresses from large number of switches after a topology change. As a result there is a sudden massive increase in flooding traffic which may cause network-wide congestion, frame delay and frame loss. Recently a new address flushing technique named as Ring Flushing was proposed for RSTP that flushes addresses from small number of selective ports of very selective switches and so dramatically reduces the amount of flooding traffic after a topology change. However, number of flaws are identified in the current implementation of this newly proposed technique. This paper will not critically discuss the flaws in the current implementation of Ring Flushing but will also propose there simple yet effective solutions.
1 Google Scholar 
2 CiteSeerX 
3 refSeek 
4 iSEEK 
5 Scribd 
6 SlideShare 
7 PdfSR 
1 LAN/MAN Standards Committee of the IEEE Computer Society. “IEEE Standard for Local and metropolitan area networks: Media Access Control (MAC) Bridges - 802.1D”. 2004.
2 LAN/MAN Standards Committee of the IEEE Computer Society. “IEEE Standard for Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – common specifications, Part 3: Media Access Control (MAC) Bridges” , ISO/IEC 15802-3, ANSI/IEEE Std 802.1D, 1998.
3 R. Perlman. “An Algorithm for Distributed Computation of a Spanning Tree in an Extended LAN”. In the proceedings of 9th ACM Data Communications Symposium. New York, USA, 1985.
4 M Seaman. “High Availability Spanning Tree”. [online] Available at: www.ieee802.org/1/files/public/docs1998/hasten7.pdf. [Accessed 21 March 2011].
5 M. Seaman. “Speedy Tree Protocol”. [online] Available at: www.ieee802.org/1/files/public/docs1999/speedy_tree_protocol_10.pdf. [Accessed 21 March 2011].
6 M. Seaman. “Truncating Tree Timers”. [online] Available at: www.ieee802.org/1/files/public/docs1999/truncating_tree_timing_10.pdf. [Accessed 21 March 2011].
7 V. Jain and M. Seaman. “Faster flushing with fewer addresses”. [online] Available at: www.ieee802.org/1/files/public/docs1999/fast_flush_10.pdf. [Accessed 21 March 2011].
8 M. Huynh, S. Goose and P. Mohapatra, “Resilience technologies in Ethernet” , Computer Networks 54(1): 57-78, 2010.
9 Cisco Systems, Inc. “Spanning Tree Protocol Problems and Related Design Considerations”. [online] Available at: www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00800951ac.shtml [Accessed 21 March 2011].
10 D. Horvath, G. Kapitany, S. Plosz, I. Moldovan and C. Lukovszki. “Ring Flushing for Reduced Overload in Spanning Tree Protocol Controlled Ethernet Networks”. Lecture Notes in Computer Science, 5733: 11-20, 2009.
11 ITU-T Rec. G.8032. “Ethernet Ring Protection Switching”, ITU-T, Geneva, 2008.
12 J.K. Rhee, J. Im and J. Ryoo. “Ethernet Ring Protection Using Filtering Database Flip Scheme for Minimum Capacity Requirement”, ETRI Journal, 30(6):874-876, 2008.
13 K. Lee, J. Ryoo and S. Min. “An Ethernet Ring Protection Method to Minimize Transient Traffic by Selective FDB Advertisement”, ETRI Journal, 31(5):631-633, 2009.
Mr. Syed Muhammad Atif
Mega In - Pakistan