Patent ID: 6839871

Claim:
A method for detecting an out-of-frame error during transmission of a message through a communications network, the message including a plurality of client provided data combined together into a message and formatted into a message format, the message format including a plurality of overhead bytes including a plurality of framing bytes and the communications network including a plurality of nodes connected via a plurality of links, the method comprising the steps of: selecting a predetermined number of the plurality of framing bytes as out-of-frame error indicator bytes; setting the out-of-frame error indicator bytes of the message to a first pattern indicative that no out-of-frame error has occurred; transmitting the message into the communications network; detecting an out-of-frame error; in the event of the detection of an out-of-frame error during the transmission of the message through the network, setting the out-of-frame error indicating bytes of the message to a second predetermined pattern indicative of an out-of-frame error occurring; receiving the framing bytes of the message from the communications network and detecting the out-of-frame error indicating bytes of the message; reading the out-of-frame error indicating bytes of the message to determine whether they are set to the second predetermined pattern; and in the event that the out-of-frame error indicating bytes of the message are set to the second predetermined byte pattern notifying the client that an out-of-frame error has occurred, generating a plurality of invalid framing bytes for the message; and in the event that the out-of-frame error indicating bytes of the message are in the first predetermined byte pattern indicative that no out-of-frame error occurred during transmission, generating a plurality of valid framing bytes for each of the plurality of client data.