What do you mean by these adaptors are CEF720?
These modules use switch fabric connectivity and Enables the use of 720-Gbps switch fabric modules for data forwarding.
Oh, I read it before... And what does this mean? "Switch fabric connectivity = supported" and "Benefit = Enables the use of 720-Gbps switch fabric modules for data forwarding". And they're talking about IPSec SIP+SPA. This probably should be translated from marketing English into the human English as follows: "Yes, SIP+SPA do have fabric connectivity (of an unknown type - either 8+8 Gbps - CEF256 or 20+20 Gbps - CEF720) and they are able to send data to other fabric enabled-modules".
So, what do exactly they use to connect to the fabric? One/two 8Gbps channels (CEF256)? Or one/two 20Gbps channels (CEF720) ???
Great if so. But now I'm stuck. It is documented that Sup32 supports SIP-200, SIP-400 and SSC-400 modules, which are CEF720 (1 20 Gbps channel), but *Ethernet* CEF720 67xx modules are *not* supported... Why ???
Becuase 67XX modules use dual 20Gig channels to connect to the fabric. Not a single 20 Gig channel.
Another point here is that when you use Sup 32 with SIP modules they use shared 32Gbps bus to connect to the fabric. Which 67xx cannot use as they require 2 20Gig channel to the switch fabric.
HTH,Please rate if it does.
This is simply incorrect. For example, WS-X6724-SFP is a single-channel module and it is still not suported by Sup32. And all the 67xx modules have both fabric and shared bus connectors.
Yes, all the 67XX modules have both fabric and shared bus connectors using CFC's. All 67XX module uses CFC to get the centralised forwarding with the shared bus connector.
6724-SFP uses a single 20GIG channel module to connect to the switch fabric.Ports 1-12 uses the shared bus connectivity and ports 13-24 has to connect to SFM using a 20Gig channel.This hardware is supported only on Sup720 as sup32 doesnot have any switch fabric builtin. This is the way architecture has been desiged. I am not sure if this can be supported on Sup32 in near future.
All the 67XX cards connect uses CFC to connect to centralised forwarding bus and only the control traffic is forwarded on the shared bus. The data traffic still has to go through the switch fabric. That's why you need a SFM with 67XX modules and since Sup32 doesnot have a SFM built in, they cannot work work with Sup32.
I've seen this somewhere... Lots, lots of questions... What kind of "control traffic"? How can 67xx cards send data to the classic (61xx) cards if they don't use shared bus for data? How do they receive traffic from the classic cards? Classic cards *always* use shared bus to pass data to *any* other card! What about SIP modules? They use centralized forwarding, right? They have both shared bus and fabric connectors, right? They're supported by the Sup32, right? How? What is the difference between the 67xx and SIP cards?
Here are you answers:
What kind of "control traffic"?
Control traffic like VTP,STP CDP, LACP/PAgP.
How can 67xx cards send data to the classic (61xx) cards if they don't use shared bus for data?
If you have sup720s,61xx card,and 67xx cards, then the 67xx cards will be in truncated (mixed
mode) mode and utilize the fabric to speak with other Fabric cards,and the supervisor. The supervisor will act in Bus mode however as the 61xx Bus cards will need the supervisor to speak to the fabric cards.
Think of it as the Supervisor will act as a "middleman" for the fabric and non-fabric cards, while non-fabric cards use the bus to
speak to each other, and Fabric cards use the Fabric to speak to each other.
How do they receive traffic from the classic cards?
As explained above
What about SIP modules? They use centralized forwarding, right?
They can use both. If ypu have a SFM they can send the datatraffic over the switch fabric, if you dont have a switch fabric, they will send the data traffic over the shared bus.
They have both shared bus and fabric connectors, right? They're supported by the Sup32, right?
They are supported by Sup32 as these module can send both constrol/data traffic over the shared bus, which is not a case in 67XX modules.
What is the difference between the 67xx and SIP cards?
The classic bus contains three 'bus types':
D-bus (data bus)
R-Bus (results bus)
and EOBC (ethernet out of band channeling).
What the 67xx cards do is use the shared bus to query the supervisor as to which port of exit each packet should go out of. Just the frame header is sent along the D-Bus to the Sup. The Sup then sends the result of this query back to the 67xx linecard on the R-Bus. The line card then uses this information to send the whole packet out the Fabric channel.
Hope this makes sense.
TAC Lan Switching engineer
Thank you for the replay. After the result is received by a 67xx card via R-Bus, do the 67xx cards *always* use fabric to pass the whole frame, even if the destination is a classic card? (Sup720 should work like a proxy in this case -- it receives the frame via the fabric and forwards it to the classic card via the shared bus.)
I think this is possible, but looks *very* strange to me. As the 67xx card has both shared bus and crossbar connections it would be much more logical to send the whole frame to the classic card directly via the shared bus in the same way like 65xx cards do.
Yes, you are right about it. Sup720 acts as a proxy between the classis cards and the fabric enabled cards. This is how the architecture has been designed.