Arista 7500R2M-36CQ Line Card

7500R and 7500R2 are respectively Jericho and Jericho+ based products. The ASICs have both on-chip and off-chip storage for packet buffers. In both cases, Arista has equipped each packet processor with 4 GBytes. The default maximum buffer for any queue is 5 mS, so 62 MByte. The default max is set to put an upper bound on delay through the switch. This parameter is adjustable. Because queuing is on input, each packet process has its own 4 GByte pool. The Jericho+ ASIC is more capable than its predecessor so fewer are needed per line card. The 7500Rs therefore has a lower count of ASICs and therefore less total buffer.

There are varients of this card with more route memory, but all with 4 GB of packet storage. The R2 has other feature differences like algomatch that are unrelated to buffer size. The block diagram of the subject card is:

line card block diagram