RELIABLE ISP ACCESS CLOUD STATE DETECTION METHOD AND APPARATUS

摘要

A Multi-Homing System is equipped with an Adaptive JSP Access Cloud State Detection apparatus (ACSD) that improves the reliability of the availability of digital connections (links) between computer sites, such as a Computer Premises Network and the Internet, in which such connections are made by connecting through a multiplicity of ISP Access Clouds (links). Reliability is improved over prior art methods by using data elements of Internet Protocol datagrams, e.g. record fields or bits of fields, that are regularly and normally exchanged between the ISP Access Clouds and the CPN without creating additional data traffic. Data Elements from each ISP Access Cloud are used by processing functions of the by the ACSD to test for conditions that indicate that it may be in a DOWN status. when a DOWN status is suspected, other functions in the ACSD initiate transmission of a set of PROBE packets that can reliably determine if the suspect link is actually DOWN or merely giving a response that would be interpreted as DOWN by prior art methods.

主权项

1. A computer implemented method, comprising:
collecting a first timestamp value from an outbound package, the outbound package directed to a destination network address through a first internet service provider access cloud; collecting a second timestamp value from an inbound package, the inbound package corresponding to a receipt acknowledgement of the outbound package; subtracting the first timestamp value from the second timestamp value to obtain a round trip time associated with the destination network address and the internet service provider access cloud; including the round trip time in a list of a plurality of round trip times in a history time table; executing a probe sequence through the first internet service provider access cloud when a down hint value for a link failure of the first internet service provider access cloud is in a high state; and determining the link failure when the probe sequence is not validated according to a timing selected from the history time table.