|shared means frame relay|
frame relay limits you by CIR [committed information rate] which is usually half of port speed [1.5mbps]. Its only advantage in my mind is you can have multiple sites connect to a single sites router interface.
You share this bandwidth with other FR users. I have found Qwest oversubscribes their FR links.
PtP or leased line is a dedicated to you. You get the full 1.5mbps bandwidth.
If you are concerned strictly about speed DSL is the way to go with vpns.
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