topic Re: Swithing Design in Switches, Hubs, and Modems

Swithing Design

skhargotre — Mon, 15 Dec 2008 12:49:08 GMT

Dear All.

Kindly find the diagram and want to know is topoligy is correct or need any modification.

Regards.
Santosh.

Re: Swithing Design

Pieter 't Hart — Tue, 16 Dec 2008 08:03:59 GMT

What do yo mean to achieve with this topology?
What are the technical limits?
Is this a topology building on an existing infrastructure (cables)?
Or do you want to build a new network?
In the latter case I would not advise to create ring-topology for the separate buildings.
Does the financial limits allow installing extra cables?

Re: Swithing Design

skhargotre — Tue, 16 Dec 2008 09:26:58 GMT

Dear Pieter 't Hart.

Thanks for reply.

Q1.What do yo mean to achieve with this topology?
Ans. I want to Know is this Topoligy is correct.

Q2.What are the technical limits?
Ans. No there in no technical limits.

Q3.Is this a topology building on an existing infrastructure (cables)?
Ans. Yes the existing setup is present.

Q4.Or do you want to build a new network?
Ans. Sugesting Modification.

Q4.In the latter case I would not advise to create ring-topology for the separate buildings.
Ans. Kindly advise which topologies is good for the case.

Q5.Does the financial limits allow installing extra cables?
Ans.yes.

Required u r expert comments on what should be the design structure for this type of network.

Regards.
Santosh.

Re: Swithing Design

Pieter 't Hart — Tue, 16 Dec 2008 10:38:42 GMT

Dear Santosh,
Your design technically will give you a network where all trafic needed, will be possible (all buldings are connected).

VLAN1 containing a little over 100 users.
has three uplinks to the core at 200Mbps.
While the library in VLAN2 has a single 300Mbps uplink for double the nubber of users.
And VLAN4 only has a single uplink!

NB! when multiple paths within a vlan are present not all are used simultanuously!
spanning-tree will put one link in "blocked" state. And no trafic will pass cross this link. It will only be enabled when another link goes down.

See attachment where I marked some links that I think will be blocked by spanning-tree.

Look at VLAN3.
When the primary uplink (300Mbps) goes down, all trafic has to pass the 200Mbps link to exam and statistic before it can reach the main network.
In this scenario it has to share the capacity with exam and statistics!
Is this fallback in capacity acceptable?

But ofcourse I don't know all the arguments for the chosen solutions.
An argument will be the tracfic between departments.
For instance if statistic and exam have a lot of communication then this could be a valid argument for a direct connection.

If this is not the case, like when most trafic is to a datacenter in another building), you'll probably be better off with a "distibution point" from a building to the main network, and all departments in a building connect to this distribution point.

If having redundant connections is an issue, you should make this distribution point redundant, with each an uplink to the main network

Re: Swithing Design

skhargotre — Thu, 18 Dec 2008 10:54:38 GMT

Dear Pieter 't Hart.

Thanks for help and u r valuble suggestion.

Regards.
Santosh.