Re: [c-nsp] 6500 dbus usage
Tim Thanks, that makes sense now :-) Jon > Date: Tue, 20 Sep 2011 08:27:12 -0700 > To: jms@hotmail.co.uk; pe...@rathlev.dk > From: tstev...@cisco.com > Subject: Re: [c-nsp] 6500 dbus usage > CC: cisco-nsp@puck.nether.net > > Hi Jon, please see inline below: > > At 07:23 AM 9/20/2011, Jon Marshall contended: > > >Thanks Peter > > > >If they do have dbus connectors then why are they not supported with a sup32. > > > The connection to the dbus is a control path only on 67xx cards, > there is no data path there. 67xx cards always use the fabric for > data plane forwarding. It's just a question of whether the lookup > happens centrally via the dbus or locally via a DFC. > > Sup32 does not have any fabric connection, so there would be no way > for traffic ingressing a 67xx card to reach the sup, or for sup > traffic to egress a 67xx front panel port. > > > > I thought it was a physical connectivity issue but apparently not. > > So is it just a performance decision made by Cisco > > > Don't worry, unlike most other things on this list seemingly, there's > not a conspiracy here. :P > > > Hope that helps, > Tim > > > > >? > > > >Jon > > > > > > > Subject: Re: [c-nsp] 6500 dbus usage > > > From: pe...@rathlev.dk > > > To: jms@hotmail.co.uk > > > CC: cisco-nsp@puck.nether.net > > > Date: Tue, 20 Sep 2011 16:15:38 +0200 > > > > > > On Tue, 2011-09-20 at 14:12 +0100, Jon Marshall wrote: > > > > My confusion is when i read on here that when the 67xx modules are > > > > running in CFC mode they send a portion of the packet (depending on > > > > compact/truncated mode) across the 32Gbps bus to the supervisor for a > > > > forwarding decision to be made. But if they don't have connectors to > > > > the 32Gbps bus then how do they access it ? > > > > > > They do have DBus connectors. Even the WS-X6708-10G-3C, even though the > > > diagram doesn't show it. > > > > > > > > <http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html#wp9000639>http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html#wp9000639 > > > > > > > As a further question, assuming they do send lookups across the shared > > > > bus then having classic linecards using the same bus could have a > > > > direct impact on the performance of the 67xx modules ? > > > > > > AFAIK it will not impact the performance of traffic staying on > > > fabric-enabled cards. > > > > > > (I'm not aware of any changes the Sup2T might introduce here.) > > > > > > -- > > > Peter > > > > > > > > > >___ > >cisco-nsp mailing list cisco-nsp@puck.nether.net > ><https://puck.nether.net/mailman/listinfo/cisco-nsp>https://puck.nether.net/mailman/listinfo/cisco-nsp > >archive at > ><http://puck.nether.net/pipermail/cisco-nsp/>http://puck.nether.net/pipermail/cisco-nsp/ > > > > > Tim Stevenson, tstev...@cisco.com > Routing & Switching CCIE #5561 > Distinguished Technical Marketing Engineer, Cisco Nexus 7000 > Cisco - http://www.cisco.com > IP Phone: 408-526-6759 > > The contents of this message may be *Cisco Confidential* > and are intended for the specified recipients only. > > ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] 6500 dbus usage
Hi Jon, please see inline below: At 07:23 AM 9/20/2011, Jon Marshall contended: Thanks Peter If they do have dbus connectors then why are they not supported with a sup32. The connection to the dbus is a control path only on 67xx cards, there is no data path there. 67xx cards always use the fabric for data plane forwarding. It's just a question of whether the lookup happens centrally via the dbus or locally via a DFC. Sup32 does not have any fabric connection, so there would be no way for traffic ingressing a 67xx card to reach the sup, or for sup traffic to egress a 67xx front panel port. I thought it was a physical connectivity issue but apparently not. So is it just a performance decision made by Cisco Don't worry, unlike most other things on this list seemingly, there's not a conspiracy here. :P Hope that helps, Tim ? Jon > Subject: Re: [c-nsp] 6500 dbus usage > From: pe...@rathlev.dk > To: jms@hotmail.co.uk > CC: cisco-nsp@puck.nether.net > Date: Tue, 20 Sep 2011 16:15:38 +0200 > > On Tue, 2011-09-20 at 14:12 +0100, Jon Marshall wrote: > > My confusion is when i read on here that when the 67xx modules are > > running in CFC mode they send a portion of the packet (depending on > > compact/truncated mode) across the 32Gbps bus to the supervisor for a > > forwarding decision to be made. But if they don't have connectors to > > the 32Gbps bus then how do they access it ? > > They do have DBus connectors. Even the WS-X6708-10G-3C, even though the > diagram doesn't show it. > > <http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html#wp9000639>http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html#wp9000639 > > > As a further question, assuming they do send lookups across the shared > > bus then having classic linecards using the same bus could have a > > direct impact on the performance of the 67xx modules ? > > AFAIK it will not impact the performance of traffic staying on > fabric-enabled cards. > > (I'm not aware of any changes the Sup2T might introduce here.) > > -- > Peter > > ___ cisco-nsp mailing list cisco-nsp@puck.nether.net <https://puck.nether.net/mailman/listinfo/cisco-nsp>https://puck.nether.net/mailman/listinfo/cisco-nsp archive at <http://puck.nether.net/pipermail/cisco-nsp/>http://puck.nether.net/pipermail/cisco-nsp/ Tim Stevenson, tstev...@cisco.com Routing & Switching CCIE #5561 Distinguished Technical Marketing Engineer, Cisco Nexus 7000 Cisco - http://www.cisco.com IP Phone: 408-526-6759 The contents of this message may be *Cisco Confidential* and are intended for the specified recipients only. ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] 6500 dbus usage
On Tue, 2011-09-20 at 15:23 +0100, Jon Marshall wrote: > If [67xx cards] do have dbus connectors then why are they not > supported with a sup32. I thought it was a physical connectivity issue > but apparently not. So is it just a performance decision made by > Cisco ? I'd guess that implementing DBus forwarding would maybe significantly limit and complexify the cards. Or something. And the Sup32 must for some reason not appear attractive at all. E.g. why can't you get an XL PFC for a Sup32? :-) -- Peter ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] 6500 dbus usage
Thanks Peter If they do have dbus connectors then why are they not supported with a sup32. I thought it was a physical connectivity issue but apparently not. So is it just a performance decision made by Cisco ? Jon > Subject: Re: [c-nsp] 6500 dbus usage > From: pe...@rathlev.dk > To: jms@hotmail.co.uk > CC: cisco-nsp@puck.nether.net > Date: Tue, 20 Sep 2011 16:15:38 +0200 > > On Tue, 2011-09-20 at 14:12 +0100, Jon Marshall wrote: > > My confusion is when i read on here that when the 67xx modules are > > running in CFC mode they send a portion of the packet (depending on > > compact/truncated mode) across the 32Gbps bus to the supervisor for a > > forwarding decision to be made. But if they don't have connectors to > > the 32Gbps bus then how do they access it ? > > They do have DBus connectors. Even the WS-X6708-10G-3C, even though the > diagram doesn't show it. > > http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html#wp9000639 > > > As a further question, assuming they do send lookups across the shared > > bus then having classic linecards using the same bus could have a > > direct impact on the performance of the 67xx modules ? > > AFAIK it will not impact the performance of traffic staying on > fabric-enabled cards. > > (I'm not aware of any changes the Sup2T might introduce here.) > > -- > Peter > > ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] 6500 dbus usage
On Tue, 2011-09-20 at 14:12 +0100, Jon Marshall wrote: > My confusion is when i read on here that when the 67xx modules are > running in CFC mode they send a portion of the packet (depending on > compact/truncated mode) across the 32Gbps bus to the supervisor for a > forwarding decision to be made. But if they don't have connectors to > the 32Gbps bus then how do they access it ? They do have DBus connectors. Even the WS-X6708-10G-3C, even though the diagram doesn't show it. http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd80673385.html#wp9000639 > As a further question, assuming they do send lookups across the shared > bus then having classic linecards using the same bus could have a > direct impact on the performance of the 67xx modules ? AFAIK it will not impact the performance of traffic staying on fabric-enabled cards. (I'm not aware of any changes the Sup2T might introduce here.) -- Peter ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
[c-nsp] 6500 dbus usage
I thought i understood 6500 architecture but after reading some of the posts on here now am not so sure ! My understanding was you basically had - 1) classic linecards - only connect to shared 32Gbps bus eg. WS-X61xx/63xx 2) fabric enabled - connections to both shared bus and crossbar switch fabric eg. WS-X65xx 3) fabric only - only has connections to switch fabric eg. WS-X67xx It's 3) i am confused about. The 67xx won't work with the sup32 and i always thought that was because these modules didn't have connectors to the shared 32Gbps bus and the sup32 only provides a connection to the 32Gbps bus. My confusion is when i read on here that when the 67xx modules are running in CFC mode they send a portion of the packet (depending on compact/truncated mode) across the 32Gbps bus to the supervisor for a forwarding decision to be made. But if they don't have connectors to the 32Gbps bus then how do they access it ? As a further question, assuming they do send lookups across the shared bus then having classic linecards using the same bus could have a direct impact on the performance of the 67xx modules ? Could someone clarify this please Jon ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
