Extreme BlackDiamond X8
Announced in 2011. Started shipping in 2012.
100 Gb/s cards accept 4 CFP2 transceivers. A chassis can support up to 32 100-G ports. The only interfaces supported are SR10 and LR4.
23. What will the switch buffer sizes on BlackDiamond X8 switches be?
The I/O modules will support a 9 Mbyte (72 Mbit) packet buffer per 24 x 10 GbE ports or 6 x 40 GbE ports. This means that the 24.port 40 GbE module will have 36 Mbyte, the 12.port 40 GbE and the 48.port 10 GbE modules will have 18 MByte. Each of the switching fabric modules (FM) will support a 36 Mbyte (288 Mbit) packet buffer. This means that the FM packet buffer total will be 144 Mbytes when four FMs are installed.
These are very modest buffers. That there is buffer in the fabric modules is interesting. This may be more useful for multicast replication than it is for buffering large flows.
Note added June 2016
Extreme has a white paper on buffers that was added to their web site in 2014. Extreme reviews the problem of network congestion -- much as this web page does. There is not a lot of exciting new material here. There is a confirmation that the kit is assembled with Broadcom trident silicon. The paper says in its concluding sections that FADT (Fair adaptive Dynamic Threshold) adapts perfectly to a wire range of workloads. But it also says [page 6]:
The paper somewhat over discusses buffer bloat and should not be relied upon in this regard. Owners of Extreme switches should use this psper to get their manufacturer's slant.