Indicates the type of a simulation service. Options: 1. invalid(-1) -indicates a connection-oriented service flow, only for read 2. default(0) -indicates a switch-oriented service flow rather than a simulation service The S-VLAN (hwExtSrvFlowVlanid) is mandatory 3. aoe(1) -indicates an AoE (ATM over Ethernet) service flow for ATM PWE3 service 4. tdmoe(2) -indicates a TDMoE (TDM over Ethernet) service flow for E1/STM-1 upstream transmission and TDM PWE3 service 5. ethernetTransparent(3) -indicates the Ethernet transparent service flow. That is, all the Ethernet traffic from the user side is transparently transmitted to the network side 6. vcloe(4) which is a virtual service channel automatically created by the system. Default: default(0) If this leaf is set to a value other than default(0), the S-VLAN (hwExtSrvFlowVlanid) of the service is invalid.