On Tue, 2005-05-03 at 09:48 -0600, Rich Adamson wrote: > TDM & X100P card users: > > Attached is a modified zaptel/zttest.c app called "attest-mod.c". It > has been modified to report the "delay" in receiving 8,192 bytes > from the TDM card (instead of reporting a percentage). It works with > the digium x100p cards as well. > > Drop the attachment in your zaptel directory and compile it with: > gcc zttest-mod.c -o zttest-mod.o > Then run the executable like this: > ./zttest-mod.o -v > and report the results. > > The output should look like: > 8192 bytes in 1.023843 seconds > 8192 bytes in 1.023866 seconds > 8192 bytes in 1.023853 seconds > 8192 bytes in 1.023876 seconds > 8192 bytes in 1.023841 secondsr > --- Results after 5 passes --- > Best: 1.023876 -- Worst: 1.023841 -- Average: 1.023856 > > The design objective of the TDM (and x100p) cards was to transfer > 8,192 bytes of data from the card in exactly 1.00000 seconds. > The above sample indicates my system required 1.023856 seconds to > accomplish this, or 23856 microseconds too late.
Isn't the design objective to read 8000 bytes in one second? The reported (roughly) 1.024 second time frame is correct for 8192 bytes. I get average numbers very close to 1.024 (especially if I take some rounding error into account). > Since the data transfer is to late, it implies that one frame of > data (or 1,024 bytes) will be dropped every 5.2 seconds on average > (or, one frame dropped for every 42 received). > > I'm about 90% sure that's why spandsp does not function correctly > and probably impacts how well the echo canceller works in some > cases as well. > > It would be very interesting to see everyone's results in running > this, and even more interesting to report the results with the OS > distro in use, mobo in use (if known), etc. If anyone actually > get's a result that is very close to 1.000 seconds, I'd really > like to know more about those systems. (email off list is fine > if you want.) _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
