Traffic engineering for VoIP network based on PSTN statistical models

Bandwidth calculation for VoIP networks based on PSTN statistical model

“…In determining busy hour traffic (BHT) intensity for certain day, we have to use simplification in which BHT is 17 percent of all traffic for that day [21]. The Erlang B traffic model [19][20][21][22][23][24] is based on the following initial assumptions: (i) an infinite number of sources, (ii) Poisson arrival process, (iii) block calls cleared, and (iv) holding times are exponentially distributed. But it can be shown that (iv) assumption is valid for arbitrary holding time distribution [20,22].…”

“…For this purpose Extended Erlang B model is used which can be calculated on the base of already calculated Erlang B model. Based on (1), Erlang B, Extended Erlang B models and their inversion functions, we have developed the software tool named Bandwidth Calculator [19]. The Bandwidth Calculator can be used to determine proper number of circuits for VoIP calls.…”

“…1, data part of ADSL traffic is transmitted using separate optical transmission network. The voice part of the ADSL traffic from all exchanges is mixed with voice traffic, from ordinary PSTN subscribers [19]. Whole data part of ADSL traffic, from NE, TO and ME, is directed via edge router in Zvornik to IP/MPLS bus to core router in Banja Luka.…”

“…Erlang based model can be applied for the network with low load and rare loss and for the high speed and highly aggregated traffic on the backbone network (network core) because that traffic tends back to Poisson [12][13][14][15][16] . Because of its mathematical simplicity, well defined and well-known conditions for the simulations, it is still useful tool [13][14][15][16][17][18][19].…”

“…Further, obtained traffic analysis is applied to VoIP network, and proper bandwidth for VoIP calls is calculated. We have developed a software tool which operates as bandwidth calculator for such network [19]. First, we calculate proper number of circuits.…”