[c-nsp] Cisco Gigabit EthernetSwitch Module (CGESM)fortheHPBladeSystem

Tue Oct 11 11:45:03 EDT 2005

Yup. It seems to me as though Cisco et al view multicast as the preserve 
of the triple play providers.
The truth of the matter is, nobody uses multicast like the financials. And 
yes, take that any way you please ;)

The guys I've met from Tibco view Cisco as the enemy of multicast, oddly 
enough. Odd, because their 
solution to everything is to upgrade the entire network to gig. To me, 
this is counterintuitive, because it just 
means multicast storms take longer to detect, and you offload the problem 
from the network to the host - which 
now may routinely be asked to  cope with half a gig of multicast traffic, 
most of which it actually needs to 
discard at the application layer. But to Cisco, it should sound like a 
sales opportunity!

Internet
dave at ordinaryworld.com
11/10/2005 16:33

To
Christian MACNEVIN
cc

Subject
Re: [c-nsp] Cisco Gigabit EthernetSwitch Module (CGESM)fortheHPBladeSystem

People don't understand the concept of TIBCO/RV and how it works.  Until
they've seen it on a live network it's all conjecture.  You make very
valid points and Cisco needs to address the financial community better in
terms of Multicast and remember that we've spent a lot more money on
multicast-related technology than probably all of the Internet combined
(which is the direction that most of their multicast technology is aimed).

-Dave

On Tue, 11 Oct 2005 christian.macnevin at uk.bnpparibas.com wrote:

> Ok, so I raise it to 110 Meg. So now all my sinks are getting 10 meg a
> second more than their ports
> can handle, so the port drops it, and the hosts NAK. Once again we have 
a
> NAK implosion.
>
> Multicast reliability mechanisms experience traffic increases as a
> function of the number of nodes
> connected multiplied by the number of multicast group memberships under
> congested conditions.
> The second we start dropping traffic from a source - whatever the limit 
is
> - everyone starts asking
> for it again, and if we start dropping some of the retransmisssions, 
then
> wahey, race condition.
>
> Once again, if anyone out there has some experience with how this might
> evolve in a live environment,
> I'm really keen to hear it.
>
>
>
>
>
>
> Internet
> jtk at northwestern.edu
> Sent by: cisco-nsp-bounces at puck.nether.net
> 11/10/2005 15:34
>
> To
> cisco-nsp
> cc
>
> Subject
> Re: [c-nsp] Cisco Gigabit       EthernetSwitch  Module
> (CGESM)fortheHPBladeSystem
>
>
>
>
>
>
> On Tue, 11 Oct 2005 11:38:41 +0100
> christian.macnevin at uk.bnpparibas.com wrote:
>
> > So let's say you limit your machine to 10% of the total link bandwidth
> > as  multicast, to force it down to 100Meg. Nice one.
> > Let's now say it tries to start sending 101 Meg. Your switch starts
> > dropping 1% of all packets. Which 1%? Who knows? So
> [...]
>
> Can't you just raise the limit to 10% plus some fudge for missed
> packets?  Presumably you shouldn't need much of a fudge, otherwise
> it would seem worthwhile to first investigate why so so many might
> be getting dropped to begin with.
>
> John
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
>
>
> This message and any attachments (the "message") is
> intended solely for the addressees and is confidential.
> If you receive this message in error, please delete it and
> immediately notify the sender. Any use not in accord with
> its purpose, any dissemination or disclosure, either whole
> or partial, is prohibited except formal approval. The internet
> can not guarantee the integrity of this message.
> BNP PARIBAS (and its subsidiaries) shall (will) not
> therefore be liable for the message if modified.
>
> 
**********************************************************************************************
>
> BNP Paribas Private Bank London Branch is authorised
> by CECEI & AMF and is regulated by the Financial Services
> Authority for the conduct of its investment business in
> the United Kingdom.
>
> BNP Paribas Securities Services London Branch is authorised
> by CECEI & AMF and is regulated by the Financial Services
> Authority for the conduct of its investment business in
> the United Kingdom.
>
> BNP Paribas Fund Services UK Limited is authorised and
> regulated by the Financial Services Authority
>
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>