Do you know what “Dynamic Truncation” is? If not, read on.

It’s no surprise that today’s modern networks require intelligent tools to support their needs. Among these include: improved efficiency, faster speeds, and increased optimization. However, it’s imperative to consider that the amount of data we monitor is also increasing. As enterprises embrace newer technologies, the focus now turns to making networks faster and more efficient with a stronger focus on a data monitoring solution to support these demands.

Most monitoring and security tools scale based on the amount of data that they need to capture and process. A common solution is a process called Static Truncation. This involves reducing the amount of packet data after 64 or 80 bytes while maintaining the information in the header. However, this process is problematic because the tools can ignore the payloads. Furthermore, Static Truncation may not be a feasible approach when monitoring systems have packets with a variable number of MPLS labels and/or VLAN.

I think we can all agree that there must be a better way to ensure that network monitoring and security tools can see all traffic data, while keeping up with massive data growth.

cPacket’s solutions are designed to meet the needs of today’s modern networks and their data monitoring challenges. cVu devices can support both Static Truncation and Dynamic Truncation. So, what exactly does Dynamic Truncation entail?  Dynamic Truncation considers MPLS label, and VLANs with the ability to truncate the packet passed the UDP/TCP header. This will guarantee the optimal size of each packet without redundancy and without losing any critical data. In addition, the overhead can be reduced further by combining the MPLS stripping feature. Pretty innovative, isn’t it?

Furthermore, cPacket’s Dynamic Truncation is intelligent enough to parse the options fields of IPv4 and IPv6, as well as the options field of TCP.

Enabling the UDP and/or TCP Dynamic Truncation feature is simple: navigate to the general configuration page and set the parameter tcp_trunc_enable and/or udp_trunc_enable to the ports you want enabled. For example, to enable TCP truncation on all network traffic entering ports 1, 7, 9 and 11 of the cVu and to enable UDP truncation on all network traffic entering cVu ports 1, 2, 3, use the following settings seen below:

tcp_trunc_enable 1, 7, 9, 11    

udp_trunc_enable 1, 2, 3


Static truncation of packets to 64, 128 or 256 bytes, respectively

Dynamic truncation of TCP/UDP packets, independent of header size

As seen in the diagrams above, enabling both Static and Dynamic Truncation will result is better visibility and performance, reduced overhead, and most importantly, improved data monitoring.

Combining agility and performance, cPacket’s cVu device solutions is network monitoring innovation at its best.