I Perspective Ring Topologies are Desirable The ability to be wrapped is vital where high reliability is important The SoNET/SDH carrier technology discussed in Chapter 7 and Module C uses a ring topology However, Token Passing is not necessary with Switched Networks Just as CSMa/Cd is not necessary in switched Ethernet networks6 Perspective • Ring Topologies are Desirable – The ability to be wrapped is vital where high reliability is important – The SONET/SDH carrier technology discussed in Chapter 7 and Module C uses a ring topology • However, Token Passing is Not Necessary with Switched Networks – Just as CSMA/CD is not necessary in switched Ethernet networks