FACILITATING AUTOMATIC PROTECTION SWITCHING FOR PROVIDER BACKBONE NETWORK

摘要

An existing protection mechanism is enhanced through the use of an automa tic protection switching protocol data unit (APS PDU). In conjunction with t ransmitting Ethernet frames to a second bridge over a primary path, a first bridge transmits APS PDUs to the second bridge over a secondary path. The AP S PDUs provide the second bridge with information about the protection switc hing mechanism being used and provide indications regarding the status of th e primary path. In particular, protection switching may be facilitated by fo rming an APS PDU that is extended to include an indication of an identity fo r a trunk or a primary path before transmitting the APS PDU to the second br idge. Alternatively, after forming a regular APS PDU, protection switching m ay be facilitated by encapsulating the regular APS PDU with information iden tifying a trunk or a primary path before transmitting the APS PDU to the sec ond bridge.