G.723 & G.711 are 2 extemes at looking at appropriate CODEC’s. Although the less compression used. If G.723 does not provide a sufficient QoS, there are other alternatives than going to a full blown uncompressed format (G.711, 64kbps). G.729 Annex B uses a compression of 8kbps, used with IP-RTP & VAC, will signifigantlty reduce the size of your header information, thus reducing the size of your packets that need to be sent and the overall bandwidth requirements needed.