VoIP Bandwidth Calculator

One of the key drivers for new VoIP deployments is the lower cost when compared to traditional telephony solutions, and a major reason for the lower costs is the type of connectivity required to connect a customer's phone system to the rest of the global telephone network. Whereas traditional phone systems require dedicated, always-available circuits to terminate voice calls, VoIP systems are able to allocate the bandwidth they require on demand; when there is no active call, the bandwidth is free for use by other applications, resulting in more efficient resource utilization.

One result of this new model is the fact that bandwidth capacity planning is an important part of any new VoIP deployment. Fortunately, Clearfly utilizes fixed-bandwidth voice codecs and a fixed packetization interval of 20 milliseconds, which means that, once all of the variables are taken into consideration, the calculations themselves are quite straightforward.


WAN Type:

Codec:

Concurrent Calls:


Per 20ms Interval

160 Bytes
20 Bytes
8 Bytes
12 Bytes
18 Bytes
218 Bytes

Per Call

50 pps
64 kbps
8 kbps
3.2 kbps
4.8 kbps
7.2 kbps
87.2 kbps
4.36 kbps
91.56 kbps

Total

50 pps
64.00 kbps
8.00 kbps
3.20 kbps
4.80 kbps
7.20 kbps
87.20 kbps
4.36 kbps
91.56 kbps

Signaling overhead is commonly estimated at 5% of the media bandwidth.

Packet Layout
Ethernet
14 bytes
IP Header
20 Bytes
UDP Header
8 Bytes
RTP Header
12 Bytes
G.711u Payload
160 Bytes
Ethernet CRC
4 Bytes

Clearfly Communications