RE: How does one decipher switch back plane numers....

[Fears Michael S SSgt 18 CS/SCBT]

Q) How do they come up with this figure?

Really what this is in reference to is the switching fabric. Many times you
hear it reffered to as backplane capacity. The switching fabric is the
shared highway that all bits traverse to get from one port to the next. The
size of the switching fabric is defined by its width in bits times the speed
in MHZ that it transmits those bits. For example:

The Catalyst 6000 has a fabric that is 256 bits wide operating at 62.5
MHz/sec. 256 X 62.5 MHz = 16 Gbps. 

This is half duplex so the actual calculation would be a 32 Gbps data
highway.  

-----Original Message-----
From: Santosh Koshy [mailto:[EMAIL PROTECTED]]
Sent: Monday, February 12, 2001 11:42 AM
To: [EMAIL PROTECTED]
Subject: Re: How does one decipher switch back plane numers....


Hello people.... I think I found my answer... I had a hard time..
Phew....Please correct me If I'm wrong... I thought I'd share it with those
that would like to know.

switches being advertised saying (10gb backplane, 1Gb backplane, e.t.c.)....
Q) What does this number actually mean?
A)  This is a number that specifies the vendor's specification for maximum
bandwidth processing capability. So for example a switch is being advertised
as 1.5gb backplane... and it has 10 ports and each port can run at
100mb/sec. The calcuation will equal to 100 * 10 = 1Gb/sec . As u can see
the backplane is not going to be congested as the max is 1.5Gb/sec and the
maximum traffic load is 1Gb/sec.

Q) How do they come up with this figure?
A) I STILL DONT KNOW...

Q) What do they mean by active backplane and passive backplane and which is
better?
A)  Backplanes are often described as being either active or passive. Active
backplanes contain, in addition to the sockets, logical circuitry that
performs computing functions. In contrast, passive backplanes contain almost
no computing circuitry. Passive backplanes are better becuase it makes
easier to repair faulty components and to upgrade to new components. So for
example, if a module on a switch gets ruined, you only need to change the
module, not the entire switch.




""Santosh Koshy"" <[EMAIL PROTECTED]> wrote in message
9643av$6n4$[EMAIL PROTECTED]">news:9643av$6n4$[EMAIL PROTECTED]...
> I have seen switches being advertised saying (10gb backplane, 1Gb
backplane,
> e.t.c.)....
>
> Q) What does this number actually mean?
>
> Q) How do they come up with this figue?
>
> Q) What do they mean by active backplane and passive backplane and which
is
> better?
>
> Thanks,
> Santosh Koshy
>
>
>
>
> _________________________________
> FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>


_________________________________
FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]

_________________________________
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]