Flow Shunting

Gain Complete, Dynamic Control Over Which Traffic Flows are Forwarded from FPGA to Application

At a high level, flow shunting allows an application to programatically turn packet transmission on or off—for a given flow (based on 5-tuple). In other words, the application can decide from which flow(s) it does and does not want to receive data traffic. By intelligently “toggling” the flow shunting switch, an application can greatly reduce the amount of data it has to analyze, thereby freeing up CPU resources for more pressing tasks.

The diagram to the right clearly illustrates the flow shunting process. Inside a security appliance there is an Accolade ANIC adapter (in PCIe slot) and the security application. The security application communicates with the adapter via a well-defined API (natively integrated into Suricata, PF_RING etc.) which it uses to configure and control the adapter. The adapter classifies each flow and subsequently sends the entire packet (header + data payload) to the application. The application in turn examines the packet (or more likely many packets in a row) and decides whether this particular flow requires further analysis or not. If the flow is not of interest then the application tells the adapter to turn flow shunting on or in other words to stop sending any packets from that flow. If for some reason the situation changes, flow shunting can always be turned off for this flow, in which case packets will resume being forwarded to the application. There may be instances when “toggling” flow shunting on and off is necessary.

There are many reasons why an application may not want to continue receiving traffic for a given flow. For example, if the application cannot process encrypted traffic there is no point in receiving encrypted flows. Or an application may not want to examine video traffic (e.g. NetFlix) because it doesn’t pose a threat or wastes too much disk space, so all video traffic could be shunted away. Or perhaps the application has an IP blacklist (or whitelist) on which it operates and therefore any flows which don’t match the list should be shunted aside. The value of flow shunting is clearly that it puts control in to the hands of the application, so that dynamic decisions such as which traffic flows should be analyzed can be made based on programming logic.

wdt_ID Speed 1G 10G 10G 10G 10G/40G 10G/40G 100G 100G 100G
1 Model ANIC-2KL
ANIC-20Ku ANIC-40Ku ANIC-40Kq ANIC-80Ku ATLAS-1000
ANIC-100Ku ANIC-200Ku ANIC-200KFlex
2 Port/Type 2 X 1G
4 X 1G
2 X 10G
4 X 10G
1 X 40G
4 X 10G
2 X 40G
8 X 10G
2 X 40G

4 X 10G
1 X 100G
2 x 100G
2 x 40G
2 x 100G
3 PCIe Interface Gen2 x8 Gen3 x8 Gen3 x8 Gen3 x8 Gen3 x8 Gen3 x8 Gen3 x16 Gen3 x16 Gen3 x16
4 Dimensions
(H x L inches)
4.25 x 6.25   4.25 x 6.25 4.25 x 6.25 4.25 x 6.25 4.25 x 6.25 1.75 x 12.28 x 14 4.25 x 9.5 4.25 x 9.5 4.25 x 6.9
5 Memory 256MB 4G 4G 4G 4G 16/32G 12G 12G 8G
6 Timestamp 10 nS 5.7 nS 5.7 nS 5.7 nS 5.7 nS 5.7nS 4 nS 4 nS 4 nS
7 100% Packet Capture
8 Gigamon,
Arista Timestamp
9 Packet Merging
10 Packet Parsing

About Accolade

Accolade is the technology leader in FPGA-based Host CPU Offload and 100% Packet Capture PCIe NIC’s and Scalable 1U Platforms. Accolade’s line of 1-100GE products enable 100% packet capture, flow classification, flow shunting, deduplication, packet filtering and more. Our customers are global leaders in network monitoring & cybersecurity applications as well as in the network test and measurement, telecom and video stream monitoring markets.

FPGA Acceleration Features

100% Packet Capture | Flow Classification | Flow Shunting | Precise Time Stamping | Packet Merging | Packet Slicing | Packet Parsing | Packet Filtering | Deduplication | Host Packet Buffer | Packet Steering | Direct Memory Access (DMA) | Statistics (RMON1)

Free Product Evaluation

Resolve all your host CPU offload bottlenecks. Share Your Technical Requirements with our FPGA and software experts to tailor the optimal solution. Accolade offers a 60 day free product evaluation for qualified customers to fully test and evaluate our products.