[asterisk-users] Storage capacity for call recording

[Steve Edwards]

On Fri, 8 May 2009, Michelle Dupuis wrote:

> I want to record calls in wav format.  Can someone tell me how many MB 
> of storage per minute each recording requires (assuming SIP / uLaw codec 
> / full duplex recording)

Your choice of technology and codec are irrelevant to the size of wav file 
produced. Wav files (as produced by Asterisk) are usually "PCM, 16 bit, 
mono 8000 Hz." Asterisk can produce funky wav49 ("GSM 6.10, mono 8000 Hz") 
files but neither monitor() or mixmonitor() support it.

Using the following dialplan snippet:

; test monitor
         exten = *,n,                    set(TIMEOUT(absolute)=600)
         exten = *,n,                    monitor(wav:,/tmp/${EPOCH})
;       exten = *,n,                    mixmonitor(/tmp/${EPOCH}.wav)
         exten = *,n(loop),              playback(demo-congrats)
         exten = *,n,                    goto(loop)
         exten = *,n,                    hangup()

I placed 6 simultaneous calls on my over-priced and under-powered Fit-PC 
(500 MHz AMD Geode):

Application     Format  CPU     File
-----------     ------  ---     ----
monitor         wav     9%      934 kilo-byte per second per leg
monitor         gsm     70%     96 kilo-bytes per second per leg
mixmonitor      wav     7%      936 kilo-byte per second
mixmonitor      gsm     36%     96 kilo-bytes per second

Remember that monitor records each leg of the call in a separate file. You 
can use the "m" option or sox to mix them together into a single file at 
the end of the call.

Thanks in advance,
------------------------------------------------------------------------
Steve Edwards      sedwards at sedwards.com      Voice: +1-760-468-3867 PST
Newline                                             Fax: +1-760-731-3000