Mesh Topology: Fault Tolerence against Cable Faults

jacklee · February 2013

Hi

I spotted a question:

John is a network engineer and is finding it difficult to troubleshoot a network cable fault. In which topology would it be difficult to detect cable faults?

And the answer is: Mesh Topology.

I learn that Mesh topology is highly fault tolerant. But I'm not sure how to think for the conclusion that it isn't good for this cable fault situation.

Please enlighten me. Thank you.

ptilsen · February 2013

Since a mesh topology can tolerate a cable fault, it would potentially be difficult to identify where the cable fault it. The network would be able to route around the cable fault, thereby making it difficult to locate or even notice.

In the real world, it would typically not truly be anymore difficult to identify a cable fault due to a specific topology because an engineer generally still has tools to detect faults between specific devices over a specific connection, regardless of topology. However, the logic of the question is sound from a theoretical standpoint.

JDMurray · February 2013

I think the author of that question believes that because there are (typically) many more connections in a mesh topology network that it would be very difficult to find a bad cable, but that just isn't the case. Counters for collisions and BER threshold are kept on each connection just the same, allowing a tech to infer a Layer 1 problem from the presence of anomalous counter values and threshold alarms.

Mesh Topology: Fault Tolerence against Cable Faults

Comments