Arista 7500R switches

Introduced March 29, 2016. Press release and architecture paper

beauty shot of circuit boards

Networkworld thinks this as based on the Broadcom Jericho switch chip. They said:

    The products leverage the Broadcom Jericho chipset which is optimized for 100 Gig-E, deep buffers and routing.

A January 2016 posting on NANOG said:

    The BCM88670 (Jericho) is what powers the new Cisco NCS55XX devices. The processor is linerate above around 100 bytes per packet without external TCAM, supports 256K IPv4/64K IPv6 FIB entries (or mixed amounts). These chips are being used for high scale 100G, the initial NCS5508 linecard is a 36x100G QSFP28 one.

    Juniper has chosen to use their own silicon for most of their dense 100G platforms, but you will see these chips used by pretty much everyone else I imagine at some point i n the next year.

Arista has an extra cost software option called FlexRoute that works like hamburger helper. It dilutes and extends the expensive TCAM [hamburger] to make it appear that there is more than it first appeared. With helper, 256K worth of TCAM is stretched to cover 1M routes, along with a promise that future recipes may cut that even further.

Arista makes explicit buffer claims in the architecture paper cited above and repeated here. Arista's Martin Hull claims 50 mS of data can be stored on each input port. There is probably some double counting here, but that should be OK.

Table 4: Default per-VoQ Output Port Limits
Output Port Characteristics Maximum Packet Queue Depth Maximum Packet Buffer Depth (MB) Maximum Packet Buffer Depth (msec)
VoQ for a 100Mbps output port 5,000 packets 1.25 MB 12.5 msec
VoQ for a 1G output port 12,500 packets 12.5 MB 12.5 msec
VoQ for a 10G output port 50,000 packets 50 MB 5 msec
VoQ for a 25G output port 125,000 packets 125 MB 5 msec
VoQ for a 40G output port 200,000 packets 200 MB 5 msec
VoQ for a 50G output port 250,000 packets 250 MB 5 msec
VoQ for a 100G output port 500,000 packets 500 MB 5 msec

Buffer monitoring

According to the data sheet:

    Latency Analyzer and Microburst Detection (LANZ)
    • Configurable Congestion Notification (CLI, Syslog) *
    • Streaming Events (GPB Encoded) *
    • Capture/Mirror of congested traffic *

    * Not currently supported in EOS