Discussion in 'MCSE' started by Chris M, Nov 13, 2008.

1. ### Chris MGuest

Hi there,

Currently studying for 297 (and boy do I hate the practise questions!).

I'm using the MS Press Training Kit. When calculating site link costs,
there is a table to refer to for various bandwidth values. One of the
test questions asks you to assign costs to various site links. One of
the site links has a bandwidth of 32Kbps, another of 384Kbps. The
reference table looks like this:

Bandwidth (Kbps) Cost

19.2 798
38.4 644
....
256 425
512 378

As you can see there are no entries that match the exact bandwidths in
the question, so I just chose a value that was in the right ballpark.
Anyway, the answer to this part of the test question was 'the site link
costs are calculated by using the formula provided in the chapter.'

Erm, what formula? A table of values isn't a formula, and the book
doesn't tell you how those values were calculated. Even if I had the
right answers I wouldn't know because they aren't given in the book!

Is there a formula for calculating site link costs? I can't figure it
out from the table... it doesn't seem to be a simple case of cost =
<some constant>/bandwidth

Cheers,

Chris M, Nov 13, 2008

2. ### WayneGuest

http://technet.microsoft.com/en-us/library/cc782827.aspx
and
http://technet.microsoft.com/en-us/library/cc749945.aspx will give you some
information. The last reference is a bit out of date, but it does contain a
formula to help work out the cost of a site link based on bandwidth only
(1024 divided by log(available bandwidth)). Real world, you'd use site link
cost based on the actual cost of a connection; a satellite link would cost
more to use than a frame relay WAN link. Or, use site link costs to act as a