[TriLUG] Managed & Unmanaged switches

[Jon Carnes]

No flawed reasoning here. Your setup works in the real world as well as
in theory... but if you are going to segregate your traffic anyway you
really don't need any managed switches.

Buy a nice router (or build a nice firewall) that has two NIC's in it - 
one that connects to your switch with VoIP phones and the other that
connects to the switch with everything else.

Then you can prioritize at the port level on the router/firewall and
simply give any traffic coming in/out via the Voice NIC high priority
and any any traffic coming in/out the Common NIC low priority.

Heck, a Linksys WRT54GS will do this and it only costs ~$90

Jon Carnes
FeatureTel

BTW: Depending on how you implement VoIP (Hosting the server yourself or
using a hosted provider) you may want to look at doing some bandwidth
shaping on your Router/Firewall.

On Wed, 2005-03-02 at 09:15, Brian Henning wrote:
> This is probably going to be right up Jon Carnes' alley:
> 
> Somewhere in the distant future, my current employer may be moving to 
> VoIP telephony.  I remember hearing that it's best to have managed 
> switching hardware supporting a VoIP infrastructure, as it allows a way 
> to guarantee that the phones always have the bandwidth they need.  My 
> question is thus:
> 
> Would it work to have one managed switch to serve the VoIP phones, which 
> would also feed an unmanaged switch to handle other nodes?  Such as 
> described by the following beautiful diagram:
> 
> }}}}
>   }}}}}}}}}
> Internet }}--[firewall]---[managed sw]----[unmanaged sw]
>   }}}}}}}}}                   |    |              |
> }}}}                         /    \              |
>                              /      \         [Rest of the computers]
>                   [VoIP phones]     |
>                             [Some computers]
> 
> (Where of course "computer" means any node that isn't a VoIP phone)
> 
> It seems to me that the above arrangement would allow the managed switch 
> to, er, manage the total allocation of bandwidth between outside and the 
> phones, and all the traffic passing through the unmanaged switch could 
> be clamped by the managed switch on its way to the outside if 
> necessary...  Right?  And that would allow us to continue getting value 
> out of our current hardware..
> 
> Or am I completely flawed in my reasoning?
> 
> Thanks as always!
> 
> Cheers,
> ~Brian
>