Originally posted by: chazzzer
Originally posted by: georgepa
swapna-
256kbps is plenty. SRs codec uses about 90kbps. during a phone call. So, you figure: 90kbps equals 900kb for 10 seconds, ~ 12 seconds for 1 MB. 12 seconds X 150MB = 1800 seconds or a good 30 minutes. Not much but enough to stay in touch on a daily basis.
You're confusing bits with bytes. If the codec is 90kilobits/sec then in 12 seconds you have 1 mega
bit. Multiply times 8 to get megabytes, so figure four hours of talk time to equal 150MB. Or, to be more accurate: 90Kb = 11.25KB, 150MB/11.25KB = 13,333 seconds = 222 minutes = 3.7 hours.
This isn't taking into account the IP & VoIP packet headers and such. If you are sending the 90kbps as 60 1500-byte packets/second then the IP packet header overhead (28 bytes) is less than 2%, but if you are sending it as 1304 69-byte packets/second (I read somewhere that 69 bytes was the default packet size for the Gizmo) then the IP header overhead is almost 29%. And that's not counting the several bytes of VoIP header information...all told about a third of your sent data would be headers. So, you might only get 2.5 hours instead of 3.7. It's also possible that the packet headers are taken into account when they quote the 90kbps rate.
Another important question would be whether the 150MB/day limit includes upstream as well as downstream. If so, divide by two.