Generally, with G.729 Codec per E1 bandwidth consumption is 936 Kbps. One E1 means 32 channels. This can be easily calculated by 31.2 Kbps per call * 30. For 32 channels with G.723 Codec the bandwidth consumption is 657 Kbps. Given by, 21.9 Kbps per call * 30. SBO can reduce bandwidth consumption to –

255 Kbps per E1, ie, 32 channels (8.5 Kbps per call) with G.729 Codec and

180 Kbps per E1, ie, 32 channels (6 Kbps per call) with G.723 Codec.