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Ethernet Packet Time Stamp Insertion Capability

Network tapping is an integral part of thorough network analysis and optimization. The CM-1600 provides maximum performance and maximum security in a 19” rack mounted packaging and its timestamping feature allows for real time analysis of aggregated and recorded traffic.

The CM-1600’s unique architecture leverages on its integrated Ethernet time synchronization capabilities and can act as an advanced timestamping server for high-precision time-stamping of Ethernet frames with wire speed network performance and sub-microsecond resolution precision time stamping. The unit provides UTC format via synchronization to its embedded GPS or PTP1588v1/v2 Slave Clock

The following time stamp modes are supported:

  • 64 bits time stamp at a pre-defined packet offset
  • 64 bits time stamp at the end of the packet

The CM-1600 EPTAP inserts the timestamp into the tapped packet or adds it at the end of the packet. Depending on the bandwidth and speed of the application, the positions of the time stamp insertion may vary to fit you application needs. The recorder receiving packets with time stamps added at the end of the packets may need to support jumbo frames since each packet will be 8 byte longer.

For low bandwidth and speeds the time stamp can be inserted at the end of the packet. If this is not possible, then a field which can be overwritten to insert the time stamp needs to be identified. The CM-1600 EPTAP has the flexibility to place the time stamp insertion anywhere in the packet after the MAC header and also at the end if the application is not at full wire speeds.

The CM-1600 EPTAP is equipped with an IEEE1588 PTP Grandmaster Clock (GMC) and Slave Clock implementation which is used for time stamp generation at the tap level.

Time Stamping of Mirrored Data becomes critical if the tapped data is not directly sent to a recorder or the recorder is not capable of performing precise time stamping of the data packets. In order to provide the highest accuracy it is necessary to time stamp the tapped data as close to the source as possible, in order to allow precise analysis of the data.

The CM-1600 EPTAP provides the capability of time stamping the data close to the wire and the time stamp for the tapped data is inserted by a time stamp module. The Time Stamp Module inserts the time stamp in the packet, either in the packet header (IP or UDP) or in the packet payload. The time stamp represents the “time” when the contents of the data packet (in the data packet) is considered to be generated at a sending node from which the tapped data originates.

CM-1600’s allows for Gigabit Ethernet monitoring and manages full-duplex gigabit at wire speed. The unit acts as an in-line and aggregator tap at speeds of 10/100/1000.

CM-1600 features front LEDs display the presence of power, network and monitor link activity, and indicate whether the TAP is in speed negotiation mode. Once in place, the CM-1600 TAP allows monitoring devices to be connected and disconnected as desired, with no impact to the network link.


  • 10/100/1000 monitoring
  • Low delay, low jitter
  • Sub-microsecond hardware timestamping for accurate latency testing
  • GPS-linked timestamping with PPS synchronization for increased precision
  • Real time statistics
  • Low level error and bandwidth monitoring
  • Quick setup and easy to use