Fiber connectivity design

[a.hajhamad]

Hi all,

This is the first time working with fiber installation , so if tou can help me in my design case:

we have three sites A,B, and C.

distance between A--B is about 2 Km, and from B-C is about 1.5 Km.

we will do the following fiber connectivity:

A-B

B-C

A-C

The provider company will use ADSS Cable 36 Fiber core between A-B through site C, so we will configure the 36 Fiber core cable as follows:

- we will make a direct connection from Site A to B

- we will make a direct connection from Site A to C

- We will make a direct connection from Site B to C.

We are planning to use WS-C3560x-24T-E switches one in each site.

My question reqarding the bandwidth available between these 3 connections, can we use either C3KX-NM-1G with GLC-LH-SM= SFPs to provide 1 Gbps speed or C3KX-NM-10G with SFP-10G-LR= SFPs to provide 10Gbps speed?

and does our choice for WS-3560X switches is a good choice?

Thanks

[Marvin Rhoads · Accepted solution]

That seems to be a workable plan.

The 3560X "-E" models have the IP Services software license which adds a good bit of cost. If you don't need all of those services, you could be just as well served by the "-S" models with IP Base software. The differences are highlighted in the data sheet.

Note that if you choose 10 Gbps you also have the option of using the C3KX-SM-10G module which adds Netflow and MACsec capability to the setup.

Also consider whether 24 ports is an adequate number at each site. It's much easier and more economical to start out with a 48 port switch than to add a second 24 port one later if your plans anticipate that sort of growth.

[a.hajhamad]

For the IP services license, i'm managing to run Dynamic Routing Protocol since the IP Base has limited DRP.

Regarding the SFPs in 1 or 10Gbs options, do they are correct especially for the distances?

in general, in our case the bottleneck is the speed of the Network module is it right? and what are the maximum bandwidth? i mean if we use the 40G module is it applicable?

i see that we may use the RJ-45 connector in the 10G option, do we need speciall convertor since we will see fiber cable terminated at the ODF in each site?

For the 24 ports, i will check it internally.

Thank you!

[Marvin Rhoads · Accepted solution]

Ok, just wanted to make sure you had thought through the need to run a routing protocol. If the network is small, often that's not necessary.

The GLC-LH-SM and SFP-10G-LR should be OK for links up to ~10 km.

The network module is your limiting factor for inter-switch speed, yes. The 10 Gbps module is the highest speed available on the Catalyst 3k series. You could put two together in an Etherchannel to get up to 20 Gbps put in such a small network it would be unusual to see the load even approach the single 10 Gbps link capacity. To move beyond 10 Gbps (or 2 x 10 Gbps) uplink capacity you would have to move up to the Catalyst 4k series.

I would not get into the copper 10 Gbps options since you have site-site fiber. One could perhaps use an external transceiver put it would not offer any benefit and pose an additional point of failure.

Hope this helps. Please rate helpful posts.

[a.hajhamad]

Thank you Marvin.

Regarding the DRP, we already have DRP enabled and we have another links between sites A and C.

thanks again