Nathan Ward wrote:
> On 26/02/2009, at 2:48 AM, David Barak wrote:
>> If two hosts are exchanging 1Gbps flows, the traffic across the bus
>> will be 2Gbps, right?
>
> You don't get to add transmit and receive together to get 48Gbps.
> Packets don't go across the backplane once to receive, and the
On 26/02/2009, at 2:48 AM, David Barak wrote:
Doesn't that assume that the communicarion is unidirectional?
...
No.
If two hosts are exchanging 1Gbps flows, the traffic across the bus
will be 2Gbps, right?
Yes. 1Gbps backplane impact per host. You have two hosts, right? One
host per por
Were not considering anything other than basic switching in this
scenario, as is my understanding.
2 hosts will create 2gbps of traffic as each host is inputting 1gbps
into the switch (just multiply it by 12 to give you 24 ports). 3 hosts
will create 3gbps of traffic as each inputs 1gbps in
Doesn't that assume that the communicarion is unidirectional?
If two hosts are exchanging 1Gbps flows, the traffic across the bus will be
2Gbps, right?
And of course, this doesn't include any bus-intensive operations like
multicast
or things which require cpu processing - those can consume a l
> Not every bit in results in just one bit out. Broadcast, multicast,
> flooding for unknown MACs (or switching failures), ...
They were talking about a simple scenario where a bit that enters a port
will leave a port. With 24 gigabit ports, for all intents and purposes,
you will only ever have
Switches like this and the force10 2410 and the like are cut through so do sub
micro second versus a 'regular' store and forward switch
--Original Message--
From: Holmes,David A
To: Deric Kwok
To: nanog@nanog.org
Subject: RE: switch speed question
Sent: Feb 24, 2009 1:03 PM
Ari
Once upon a time, Roy said:
> I think your math is faulty. While there may be 24G going in and 24G
> going out, there is only 24G crossing the backplane. You can't count a
> bit twice (once on in and once on out). Its the same bit.
Not every bit in results in just one bit out. Broadcast, mult
Eric Gearhart wrote:
>
>
> Note that the traffic to a switch is bi-directional (full duplex) - so
> a 24 port gigabit switch can max out its 32 Gig backplane, if all 24
> ports have a gig coming in and going out (24 X 2 is 48, more than the
> 32 gig backplane).
>
>
>
I think your math
Arista claims to have the fastest 1/10 Gig 24 and 48 port 1RU switch,
with a backplane capacity guaranteeing 10 Gig full duplex line rate per
port.
Cisco's CEF is local only and functions to download the arp cache and
routing table into ASICs for hardware switching; but look at Cisco's
NSF/SSO fo
That isn't always true. Some switches are already speced as full. It's
best to read the product docs or speak with a rep to be sure.
tv
- Original Message -
From: "Eric Gearhart"
To: "NANOG list"
Sent: Tuesday, February 24, 2009 9:51 AM
Subject: Re: s
On Tue, Feb 24, 2009 at 2:33 AM, Bruce Grobler wrote:
> Hi,
>
> It depends on how heavily loaded your switch is expected to be, for instance
> two machines using the switch will be able to get a full 1Gbps, however
> depending on the backplane (switching fabric), it limits how many ports will
> re
Hi,
It depends on how heavily loaded your switch is expected to be, for instance
two machines using the switch will be able to get a full 1Gbps, however
depending on the backplane (switching fabric), it limits how many ports will
receive full 1Gbps when the switch is congested, e.g. a 2 gig backpl
Can you elaborate a bit on your question? The fastest "Gig switches"
can do 1GB full speed on the port. There are many that can do that.
Do you have a particular density you need to do full speed with? Any
particular features? Are you looking at any particular models now, in
others words
13 matches
Mail list logo