VoIP Calls Calculator
This spreadsheet allows you to assess the bandwidth required for VoIP calls. It is only approximate and the maximum number of calls does not account for other traffic and potential limiting factors.
   
Codec  
Link Type  
IPHC
Link Size
L2TP  
IPSec  
       
Double this for two-way speech on Ethernet links.
Assumes VoIP traffic only.
       
Packets per Second  
Algorithmic Delay (ms) Fixed delay caused by codec application.
Target Delay - Less than (ms) Maximum delay (latency) for calls.
Ping Test Maximum (ms) Round-trip ping delay to be within target.