常用的 VOIP CODEC

Codec	Bandwidth/kbps	Comments
G.711	64	Delivers precise speech transmission. Very low processor requirements. Needs at least 128 kbps for two-way.
G.722	48/56/64	Adapts to varying compressions and bandwidth is conserved with network congestion.
G.723.1	5.3/6.3	High compression with high quality audio. Can use with dial-up. Lot of processor power.
G.726	16/24/32/40	An improved version of G.721 and G.723 (different from G.723.1)
G.729	8	Excellent bandwidth u utilisation Error tolerant. License required.
GSM	13	High compression ratio. Free and available in many hardware and software platforms. Same encoding is used in GSM cellphones (improved versions are often used nowadays).
iLBC	15	Robust to packet loss. Free
Speex	2.15 / 44	Minimises bandwidth usage by using variable bit rate.

VOIP Bandwidth 計算機

VoIP Bandwidth Calc is a calculator designed to help voice network engineer to calculate how many bandwidth is required for VoIP Channel.How many bandwidth is actual required for 8kbps G.729 channel?
How many channel I can run on the E1 link?Here are the answers,VoIP Bandwidth Calc is a calculator designed to help voice network engineer to calculate how many bandwidth is required for VoIP Channel. You can select different codecs, different voice payload size, Layer2 network type, number of concurrent channel and compressed RTP enable or not and VoIP Bandwidth Calc will tell you how many bandwidth will be actual required for voice channel.

VoIP Bandwidth Calc - screenshot thumbnail