Generating and Using Timestamps

[The TCP chimney offload feature is deprecated and should not be used.]

The host stack and offload target must synchronize the generation of TCP timestamps. This synchronization allows the host stack and offload target to generate timestamps that increase monotonically, even if the TCP connection is offloaded or the offload of the connection is terminated.

Note that the timer that is used for the timestamps should be calibrated to the granularity that is specified by the host stack in the TicksPerSecond member of the NDIS_TASK_TCP_CONNECTION_OFFLOAD structure. The host stack supplies this structure when setting the OID_TCP_TASK_OFFLOAD OID. The host stack can specify a timer granularity of 10, 100, or 1000 ticks per second.

This section includes:

Calculating the Timestamp Delta

Generating a Timestamp

Calculating the Merged Round-Trip Time

Examples of Timestamp Processing