
228 ◾ IP Communications and Services for NGN
Experimental Network Models
With three network models, Choudhary et al. [10] measured the link utilization of
the inter-proxy-server link (IPSL), the link utilization of the auxiliary link (AUXL),
the average end-to-end delay of the SIP signaling packets, the average end-to-end
delay of fax data packets, the average SIP call setup time, and the average fax call
setup time.
1. In Network Model 1, calls are generated from the T.38 gateway, and all mes-
sages are sent to the SIP proxy server on its network. e path between the
T.38 gateway and the SIP proxy server contains an IP router. Although th