Fibre Optic Switches

[keltoiboy]

Hi

I'm doing a project for 1st year university studies and would appreciate some input. I have to design a hypothetical network for a business running 300 PCs, the business is spread across 2 buildings both of 3 stories (levels). My hypothetical design is based on a Tree Topology (multiple Stars) with a Layer 3 Switch feeding at least 6 Layer 2 switches (1 on each level of each building). The switches are linked by Fibre-Optic cabling to ensure the Layer 2 switches have enough capacity coming in to feed the maximum number of PCs that will connect to them (48). The PCs connect to the Layer 2 switches by Cat6a cabling.

After looking at what is available from Cisco I see there is a huge variety of switches available so after contacting Cisco and being advised to ask my question here I am posting here to see what switches people would recommend to suit this hypothetical network.

Thanks in advance.

Cheers.

Michael.

[Seb Rupik]

Hi Michael,

For core I'd suggest a pair of 4503-E switches as a VSS pair.

http://www.cisco.com/en/US/products/hw/switches/ps4324/index.html

Your edge switches should be 2960S-48TS, with a GE or 10Gb fibre going to each 4503-E to form a vPC pair.

http://www.cisco.com/en/US/products/ps6406/index.html

Depending on whether you choose GE or 10Gb fibres to the core, you will either need a 12-port 10Gb line card (WS-X4712-SFP+E) for each 4503-E, or a 12-port GE line card (WS-X4612-SFP-E). The 12 port line cards will give you some head room for furutre expansion.

You will also need to choose a superviosr line card for each chassis.

Don't forget to include all the SFP's! That should do it.

cheers,

Seb.

[keltoiboy]

Hi Seb.

Thanks for your recomendations. My intent is to run (hypothetically) at least a 10GbE switch setup so that the switches and Fibre-Optic cable are, to a certain extent compared to the rest of the network, "future proof" for at least 5 years. The swtiches to the workstations would run Cat6a cabling which in theory should negate problems associated with cable length but also not have the expense assciated with Fibre-Optic due to the cable itself plus the different connectors.

When you mention "supervisor line card for each chassis" you have given me something to research more because this has not been brought up in the unit I am working through.

Thanks again Seb.

Cheers.

Michael.

[Leo Laohoo]

Michael,

What you are "planning" has so many combinations.  But this can easily be elimated by the size of your "budget" and how you want it done.

The most "basic" one is this:

Distribution Switch:  3750X-12S or 3750X-24S;

Access Switch:  2960S (up to 192 ports) or 2960X (up to 432 ports);

Core Switch:  4500R+E with Sup7 or Sup8 < --- Sup 8 is a Sup7 with a built-in wireless LAN controller (up to 100 APs)

Pro:  Distro to Core @ 10 Gbps per link (or up to 80 Gbps in an etherchannel).

Pro:  Access to Distro at 1 Gbps only

Pro:  Cheap

Pro:  Simple

Con:  Can't scale the speed between access switch to distro without upgrading the distro switch

Cisco's new architechtural design of a collapsed core/distro:

Access switch:  6800ia

Core/Distro:  6807X/6880X or 6500E with Sup2T and 6904 line card to support 6800ia

Pro:  10 Gbps uplink (per link) from access to core/distro

Pro:  Core/Distro can be interlinked to form a VSS with support of 40 Gbps and 100 Gbps (if memory serves me correctly).

Con:  Each access switch can only do 48-port minimum.

Con:  Expensive

[keltoiboy]

Hi Leo.

Thanks for your post. Looking at the pages for each switch you list I think my best option, even with its Con, is the "basic" option.

While I personally like the second option I am thinking the expense involved compared to the first would make it difficult to convince any medium sized business (especially in todays economic climate) to go that with that option. Considering technology is moving so quickly both systems would be obsoleted by the time a new network was required.

Thanks again, you have been extremely helpful

Cheers.

Michael.

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Redundancy, redundancy, redundancy!  What's the cost of network downtime to the business?

For a relatively inexpensive network, that supports redundancy, you might start at the edge with stacks of 2960s.  These would have at least dual gig etherchannel link to the building's (single) L3 switch.  (Additional gig links within the etherchannel, or 10g etherchannel, are options, but unless your PCs are Pixar workstations, you'll probably find dual gig will support user PCs for some time yet.)  That switch, again for relatively inexpensiveness, might be a dual stack of 3750X (SFP variants), or more expensively, a pair of 4500Xs in VSS configuration.  The building L3 switch would also have a dual etherchannel (10g) pair to the other building's L3 switch.

You didn't mention servers, but if you have those, if using the 3750X stacks, you could add a couple of copper 3750X to the stack and dual home your servers too.  If using 4500Xs, you'll need a server edge, which could run as L2, but something better than 2960 series, but also with redundancy.  It might be a stack of 3750X/3650/3850 with servers dual homed (to different stack members).  10g etherchannel to the 4500x pair.