System for sending messages in a session using a mixture of protocols and preventing usage of a protocol when the message failing to meet a set of criteria

摘要

A session-oriented local area network (LAN) application and an ISO 8802-2 protocol driver code will cooperate in a new form of connectionless, session-oriented communication called Sideband. At each session start-up time, the LAN Application will communicate with the enhanced ISO 8802-2 based protocol driver on the local system and the LAN Application and the 8802-2 based protocol driver on the remote system to determine if they all support the Sideband. If Sideband is fully supported by both systems, Sideband will be activated for the session. To communicate on a session which has Sideband active, the LAN Application requests that data is to be sent using the Sideband. A check is performed to see if the data meets Sideband criteria. As Sideband is a connectionless medium, the additional code path needed to set up and track timers and to handle the resend attempts are saved in the protocol. If the LAN Application code is session-oriented, it will keep track of a timer which will cause the data to be resent along a non-Sideband path if a response is not received within a designated amount of time. Header information is stored and reused to increase the throughput and decrease the response time for the transmission of small network packets. In case the network at some points becomes unreliable, procedures are used to track the reliability of the network and to enable and disable Sideband in accordance with the reliability of the network.