why the trafficis calculated. to determine if the traffic between the nodes is bearable on that link. To plan the size of the network.
In our country. We mostly run the traffic measurments in the transit exchanges. Ie to know the bulk of traffic.
the traffic programme outputs the measuments in 15 min intervals.
Any post processing programme can give the out put in what ever format u want.
What I woulf suggest is that u run the TGRP measurments on the circuits which connect theses centres.
The u can find out BHCA, BHCC, ASR on that particular directions.
Most of the public switches offer the services to measure these values.