About Timestamps

Timestamps provide high-definition timing information for installations where packet timing is critical, particularly in high frequency trading, financial, and service provider environments. Timestamps are easily correlated across worldwide installations, improving your ability to monitor latency, Quality of Service (QoS), jitter, and end-to-end network performance across multiple instrumentation points.

This feature provides you the ability to append timestamps to ingress or egress packets. Timestamps are used in conjunction with Precision Time Protocol (PTP) for synchronization with a UTC reference clock.

You can choose to append timestamps to ingress packets, or to egress packets, or to both ingress and egress packets. Figure 1 illustrates how timestamps are added to ingress and egress packets.

 

Figure 101

Timestamping

In this figure, the original packet is ingress timestamped on the 1/1/c1 port in a GigaVUE-TA200 device and egress timestamped on the 1/1/c3 port. The packet is then forwarded to the next device, where ingress and egress timestamps are again added at the 2/1/c3 and 2/1/c2 ports respectively. Thus, the packet has both ingress and egress timestamps with unique source leader in a bidirectional clock relationship (formerly master) IDs for each port, appended to its header. The source IDs provide port identification where timestamp is applied. You can add a maximum of two timestamps for a packet in a device.