Table of Contents
Advertisement
Example 5: TDM and media processing usage
Consider the COI matrix in
matrices
on page 160 in
calls originated in Site 1 and terminated in Site 1 (that is, the upper left group of nine cells,
arranged in a three-by-three submatrix). The uppermost and leftmost cell of those nine cells
indicates that the IP-to-IP call usage for Site 1 intrasite calls is 12.7 Erlangs. The other four cells
of those nine cells which fall in a row or column that is labeled "I" indicate that the total call
usage between IP endpoints and circuit-switched endpoints (including PSTN trunks) within Site
1 is (7.5 + 30.9 + 7.5 + 30.9) = 76.8 Erlangs. The remaining four cells of those nine cells indicate
that the total call usage between two circuit-switched endpoints (including PSTN trunks) within
Site 1 is (4.4 + 18.1 + 18.1 + 0) = 40.6 Erlangs. Analogous numbers for intrasite usages that
correspond to the other two sites are similarly derived.
Next, consider the three-by-three submatrix that corresponds to calls from Site 1 to Site 2. The
total call usage from Site 1 to Site 2 which involves an IP endpoint in Site 1 can be determined
by adding the three cell values of those nine cells that correspond to IP endpoints in Site 1.
Specifically, the total is (5.2 + 2.3 + 0) = 7.5 Erlangs. The total call usage from Site 1 to Site 2
which involves a circuit-switched endpoint (including PSTN trunks) in Site 1 can be determined
by adding the remaining six cell values of those nine. Specifically, that total is (3.1 + 1.4 + 0 + 0
+ 0 + 0) = 4.5 Erlangs.
The total call usage from Site 1 to Site 2 which involves an IP endpoint in Site 2 can be
determined by adding the three cell values of those nine that correspond to IP endpoints in Site
2. Specifically, the total is (5.2 + 3.1 + 0) = 8.3 Erlangs. And finally, the total call usage from Site
1 to Site 2 which involves a circuit-switched endpoint (including PSTN trunks) in Site 2 can be
determined by adding the remaining six cell values of those nine. Specifically, that total is (2.3 +
1.4 + 0 + 0 + 0 + 0) = 3.7 Erlangs. Analogous numbers for the other five combinations of
intersite usages are similarly derived. The results are shown in
CURs from Table 28: Completed COI matrix for Example 4: Expanded COI matrices on
page
160.
Table 29: Recategorization of CURs from
Example 4: Expanded COI matrices
Endpoints
Intrasite: I, I
Intrasite: I, C or P
Intrasite: C or P, C or P
Calls from Site 1
to Site 2
Table 28: Completed COI matrix for Example 4: Expanded COI
Example 4: Expanded COI
Site 1
(Atlanta)
12.7 E
76.8 E
40.6 E
I
7.5 E
C or P
4.5 E
matrices. A set of nine cells corresponds to
Table 29: Recategorization of
Table 28: Completed COI matrix for
on page 160
Site 2
(Boston)
1.9 E
26.7 E
11.4 E
8.3 E
3.7 E
Issue 3.4.1 June 2005
Resource sizing
Site 3
(Cleveland)
0.78 E
14.4 E
1.9 E
0
0
1 of 2
169
Advertisement
Table of Contents
