Multicast Susbcribe

Posted by fmadio | 100G Ethernet

New features on our 20GbE packet capture system has been released, automatic Multicast join`s. Usually packet capture runs using a SPAN/Mirror port Layer 1 optical taps with the capture port being strictly Rx only. Yet sometimes this isn't enough and the capture port needs to manually join multiple sessions.

  • multicast join
Why join IGMP multicast groups?

The requirement is driven by HFT Finance where market data is always ( ^H^H^H cough puke cough... OSE) transmitted over UDP multicast. Which is great if you`ve got applications subscribing and joining IGMP multicast groups. Then SPAN or TAP from the switch works perfectly to capture all the traffic. However if there`s no applications running, with no multicast subscribers, your tough out of luck and no market data gets captured.

.. until now! Our FMADIO 20GBps Capture system can now issue almost unlimited IGMP joins directly on each capture port. It`s not the most elegant solution, as it issues gratuitous ARP and IGMP Query`s. But it keeps the Rx capture path, and Tx ARP/IGMP path completely separated, resulting in zero impact on capture performance.

We`ve been so incredibly busy the last few months, with not so many blog updates as having trouble keeping up with all the orders! We`re moving to a new larger office in central Tokyo and Interop Japan starts in early June where we`ll be front and center stage. If your going to Interop Tokyo drop us a mail that you`ll be around.