Capturing in Time-Sensitive Networking Environments with ProfiShark 1G

Time-Sensitive Networking (TSN) is a set of standards defining mechanisms for the time-sensitive transmission of data over Ethernet networks. Deterministic communication is critical to multiple industries (Audio Video Bridging, Automotive, Industrial and Power automation, Mobile Fronthaul Networks).

The purpose of this article is to demonstrate the benefit of ProfiShark 1G in TSN environments and to describe its usage. In order to support TSN, a TAP has special requirements in terms of latency, jitter and capture capability.

Time-Sensitive Networking

Transparent In-Line

Like all Profitap’s in-line TAPs, the ProfiShark is protocol agnostic and L1 passthrough for all frames, tags, and encapsulations. This includes preempted frames (IEEE 802.1Qbu/802.3br), fragmented and CRC-invalid frames.

The in-line latency and the jitter introduced by the in-line circuit is minimal, making it suitable for IEEE 802.1AS and 1588 v2.

DEVICE
LATENCY
JITTER
L1 PASS-THROUGH
ProfiShark 100M
2 ns
100 ns
Yes
ProfiShark 1G/1G+
400 ns
32 ns
Yes
ProfiShark 10G/10G+
300 ns
40 ns
Yes

Capture Capabilities

The ProfiShark 1G is capable of capturing any type of frame, including preempted frames (IEEE802.1Qbu/802.3br), fragmented and CRC-invalid frames.

FRAME TYPE
PREAMBLE COUNT
SMD
FCS
Standard / Express
7
0xD5
CRC
SMD-lx Premptable frame start
7
0xE6, 0x4C, 0x7F or 0xB3
CRC
SMD-Cx Non-initial fragment
6
0x61, 0x52, 0x9E or 0xAD
CRC ^ 0xFFFF0000

Moreover, the ProfiShark Manager offers an option to capture the entire L1 Ethernet frame in direct capture. When ‘capture full frames’ option is enabled, the frames are captured with the preamble (0x55), the SMD and the CRC.

Wireshark Integration

With ‘capture full frames’ option enabled, the PCAP-NG Link-Layer Header is set to LINKTYPE_ETHERNET_MPACKET. This Link-Layer type is fully supported by Wireshark since 2.6.0 and allows proper dissection of L1 frames (see Wireshark view below). Once dissected, the additional L1 data is displayed in the Packet detail view and doesn’t conflict with higher protocols. Additionally, fragmented preempted frames can be reassembled in Wireshark.

The ProfiShark Manager offers different capture options. The different capture options and their effect are listed below.

All-In-One Advanced Gigabit Network TAP

ProfiShark 1G is one of the most powerful, compact portable network tap devices. It’s a portable troubleshooter dedicated to network monitoring, combining both performance and flexibility.

This pocket-sized Gigabit TAP is the equivalent of an aggregator tap and two NICs, requiring only a laptop or a desktop PC with a free USB 3.0 port. ProfiShark 1G is the ultimate solution for your field testing and monitoring performance.

All our ProfiShark products also include other important features, as are hardware filters, statistics and configuration options, through our own ProfiShark Manager application.

ProfiShark 1G+ combines all the features of ProfiShark 1G but with added GPS and PPS features for advanced timestamping.

All-In-One Advanced Gigabit Network TAP
ProfiShark 1G+ with laptop
Link to product pages: ProfiShark Portable Network TAPs