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Daisy chain switches architecture

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Nov 9th, 2010
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Hi, I have to create a wireless network for a railway along a gallery 2.5km long. I am thinking about a daisy chain architecture compose by industrial switch positioned along the gallery and linked together in a daiysy chain topology by uplink fiber SFP module, and use Rapid Spanning Tree to avoid loop.

Is it a correct architecture or it could have some problems as lost packets or delay due the lan diameter too much long?

Do you suggest another best suited architecture?

Thanks in advance for every help.

best regards

angelo


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lgijssel Tue, 11/09/2010 - 09:09
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With RSTP you will have a max diameter of 16, so that should not be a problem.

Still you may consider to create several smaller rings to improve performance and remain on the safe side regarding STP diameter.

Most fiber cables have multiple strands so the required fiber capacity will be available.


One thing to keep in mind though: Cable length. The max cable length (100FX multimode) is 2km.

http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6578/product_data_sheet0900aecd801f931c.html


You will need to place your central switch somewhat further up so that all cables remain within the max distance or utilize LX (single mode).


regards,

Leo

ANGELO DE MASI Tue, 11/09/2010 - 09:53
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Thank you very much Leo, it's very clear and it's exatcly what I expected to hear.


Best regards

angelo

ANGELO DE MASI Tue, 11/23/2010 - 03:37
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Hi Leo,

sorry could you still give me an advice? Speaking on the same architecture, what about scalability? How could I expand the campus if I had the need to extend my wireless network along the railway line? My idea is to put another switch in a second rail station and make it a part of the fiber ring, then build a new ring starting from it, and so on.

Do you think it's a right architecture? Could I figure out many loss and delayed packet issues? How many times it is possible to scale this architecture.


Any help will be much appreciated.

Thank you in advance.

Kind regards.

angelo

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