Re: 3750 switch hardware buffer :(

Thanks Guys, You Rock :)

Regards
Dave

On Tue, May 19, 2009 at 5:13 PM, Pavel Bykov <slidersv_at_gmail.com> wrote:

> Actually, Dale, that's partly true.
>
> 1. 2960/3560/3750 do have a very similar hardware architecture, with
> internal rings running between asics. When there is only one ASIC, the
> packet moves from ingress ring to egress ring via an internal loopback
> interface.
>
> 2. There is a difference in types of switches, primarily 8/12/24/48 port
> and Gig/Non-Gig.
>
> 3. There is a rule of thumb you can use: 10/100 switches have always 2MB
> shared SRAM buffer for egress, therefore 24-port or 48 port all have the
> same buffer size. This space is shared among all the ports, but can be
> reserved.
> A very descriptive but not too accurate guide is written by Cisco on buffer
> segmentation and reservation is here:
>
> http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a0080883f9e.shtml
>
> 4. For Gigabit switches, there are different ASICS, and to understand what
> you're doing you have to first map a port to ASIC.
> All ports that fall under one ASIC share one buffer - it's the 384KB and is
> located directly on the ASIC. So for example port 1 (connected to ASI3) is
> never be able to use buffers of port 2(connected to ASIC 0). Ports are not
> connected to ASICs sequentially. e.g. to ASIC 3 you'll have the following
> ports connected: 1,5,8,13, etc...
>
>
> This is for egrees buffers.
>
>
> On Mon, May 18, 2009 at 12:52 PM, Dale Shaw <dale.shaw_at_gmail.com> wrote:
>
>> Hi,
>>
>> On Mon, May 18, 2009 at 8:41 PM, dave dave <funccie_at_gmail.com> wrote:
>> >
>> > I wanted to kneo 3750 hardware buffer, I am unable to find it on Cisco
>> as
>> > well as on the box itself. Can you please point me to some URL or tell
>> me
>> > the command to check the hardware of 3750.
>>
>> This was asked on cisco-nsp today --
>>
>> https://puck.nether.net/pipermail/cisco-nsp/2009-May/060703.html
>>
>> John Jensen jensenja at gmail.com
>> Mon May 18 04:52:20 EDT 2009
>>
>> "0.75MB of ingress buffering is dynamically divided into port
>> buffers/queues, 2 of which are user-configurable. There's 2MB of
>> egress buffering that provides 4 egress queues per physical port."
>>
>> Does that help?
>>
>> cheers,
>> Dale
>>
>>
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>
>
> --
> Pavel Bykov
> ----------------
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Received on Wed May 20 2009 - 08:08:22 ART