From: Colin Barber (Colin.Barber@xxxxxxxxxxxxxx)
Date: Wed Aug 28 2002 - 17:28:20 GMT-3
Interesting, this may have been the start of the confusion. I will speak to
somebody tomorrow in our operations department about how my company's frame
network is set up for Tc.
Incidentally, as long as the Telco's Tc is larger than the router's Tc
things should work fine, although it's best to have things match. If your Tc
is smaller than the telco's Tc, your Bc is also smaller. Therefore at each
Tc you place Bc onto the wire which is smaller than the maximum the telco
will accept.
For example. Telcos Tc=1 sec. Your Tc=0.5 sec. CIR = 10000. Therefore Telcos
Bc=10000 and your Bc=5000. In the first Tc you transfer 5000 bits and then
again in the second Tc. The total is 10000 over a 1 second period which the
telco accepts.
If this is the other way around you can have problems. Within your Tc of 1
second you transfer 10000 bits. Now this transfer does not happen evenly
over the 1 second time interval and your access speed allows the whole
transfer to takes just 0.1 sec. The telco is still within it's its first 0.5
second Tc and you have now exceeded your allowed Bc by 100%.
Maybe this is why some telcos have large Tc, to cut down on problems?
Colin
-----Original Message-----
From: Volkov, Dmitry (Toronto - BCE) [mailto:dmitry_volkov@ca.ml.com]
Sent: 28 August 2002 20:31
To: 'ccielab@groupstudy.com'
Subject: RE: I need FRTS help or review
I remember somebody mentioned before that in Europe usually Tc= 1 sec
Maybe this is the reason of confusing, because "port speed <= Bc + Be" ;
96K =64K-32K in this case
Dmitry
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