Many thanks for your clarification. Thanks and regards, Xu Hu
On 14 Jun, 2012, at 7:09, Łukasz Bromirski <[email protected]> wrote: > On 2012-06-13 05:55, Pete Templin wrote: >> On 6/12/12 11:06 AM, Łukasz Bromirski wrote: >> >>> In reality, Sup720-10GE sold with the "VS" prefix is a >>> perfectly normal Supervisor. What is changed is that the >>> fabric matrix is actually 20x20Gbit/s not 18x20Gbit/s, so >>> you get additional 2 channels for 20Gbit/s. >> >> Oh, is that for the 6511 chassis? > > 6511? Never heard about it. > >> 18x20Gbit/s means 2x20Gbit/s per slot * 9 slots, so the Supervisor slots >> already have 2x20Gbit/s feeding them to drive the front-panel ports. > > Why would they need a 19th or 20th channel? > > To drive the uplink (2x10GE) at full speed without oversubscription, > as those are VSL links. > > In old Sup720 design, the Supervisor itself is connected to the > fabric using one channel. This channel is used by Hyperion ASIC > to provide for bus interface, and multicast/SPAN features. Because > there's no other way to connect the uplinks on the Sup itself, the > Hyperion has it's interface also terminating the uplinks (2xGE) > thus limiting effective throughput/etc. BTW, both PFC and MSFC > are also connected to the rest of the chassis linecards by Hyperion > (PFC) and Pinnacle (MSFC). > > On the Sup720-10GE, the separate, 19th channel is used to connect > the uplinks directly into fabric. Hyperion is still there, it still > takes the channel "belonging" to the slot which Supervisor itself > is in, but thanks to such design doesn't limit in any way > performance you can achieve on the 2x10GE uplinks (or 4xGE). In > the new design, Hyperion takes care of providing connectivity to MSFC3 > complex, while Metropolis (ASIC terminating the uplinks and connected > to fabric) takes care of providing transport to PFC3C/CXL. > > The 20th channel is used in the same fashion for the redundant > Sup if it's inserted into chassis. > > Hope that clears it a bit. > > -- > "There's no sense in being precise when | Łukasz Bromirski > you don't know what you're talking | jid:[email protected] > about." John von Neumann | http://lukasz.bromirski.net > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
