ex circuit, typical of standard PSTN telephony. ITU-T Rec. G.114 [10] recommends the total delay (one-way) in a voice connectivity as follows: 15.4 VOIP, INTRODUCTORY TECHNICAL DESCRIPTION Type of Service Total Length Identification Flags Fragment Offset Protocol Header Checksum Source IP Address Destination IP Address Options Padding Information (payload) Figure 15.6 A typical IP packet (datagram). Based on RFC 791. Also see Figure 11.28. 0-150 msec acceptable. 150-400 msec acceptable but not desirable. Connectivity through a geostationary satellite falls into this category. Above 400 msec, unacceptable. The delay objective (one-way) for a VoIP voice connectivity is < :100 msec. With bridging for conference calls, that value doubles due to the very nature of bridging. One-way components of delay are as follows: Packetization or encapsulation delay based on G.711 or other compression algorithm. In the case of G.711, we must build from 80 PCM samples at 125 usec per sample, SO we have consumed 80 X 125 usec or 10,000 usec or 10 msec plus time for the header or 48 X 125 usec or 6 msec, for a total of 16 msec. If we use 160 PCM samples in the payload, then allow 20 msec plus 6 msec for the header or 26 msec. This is a fixed delay. Buffer delay is variable. As a minimum, there must be buffering of one frame or packet period. Routers have buffers, by definition. Buffer delay varies with the number of routers in tandem. For G.711 the packet buffer size is 16 or 26 msec. Look-ahead delay. This is used by the coder to help in compression. "Look-ahead" is a period of time where the coder looks at packet N + 1 for patterns on which it can compress while coding packet N. With G.711 the look-ahead is 0. Dejitterizer is a buffer installed at the destination. It injects at least 1 frame (packet) duration (1-20 msec) in the total delay to smooth out the apparent arrival times of packets (frames). VOICE-OVER PACKETS IN A PACKET NETWORK Queueing delay. Time spent in queue because it is a shared network. One method to reduce this 