TIP: Click on subject to list as thread! ANSI
echo: hs_modems
to: DAVE PETRUCCI
from: MIKE FARRILL
date: 1997-04-09 14:37:00
subject: Re: 4400cps on a 33600/3

-> >-> 2) Max modem-modem throughput at 33,600, with error correction is
-> >-> 4200 bps.  EC overhead reduces this to the 4000 cps range.
->
-> >Is the EC overhead you are refering to come from the use of the Zmod
-> >protocol?  Y-modem-g is always faster.  And also, he could be using
-> the
->  >512k lap-m packet size which would give more performance.
->
-> Mike,
-> A 33600bps non EC connect is capable of 3360cps...
-> (10bits/char =  (8 data bits, 1 start bit, 1 stop bit))....
I've seen more than that with 28800 connections...
-> With error correction, V.42 (LAPM or MNP4), the data is
-> blocked and the start/stop bits removed... thus 8bits/char..
-> A 33600bps EC connnect is capable of 33600/8 = 4200cps..
-> The overhead Rick was refering to is a result of the control
-> functions of the error correction itself... of course the
-> larger the blocks, as you've suggested, will improve overall
-> performance, but never above the 4200cps...
Thanks for the Info, but lines around here aren't that good, so I'll
probably never see 33600...
--- Platinum Xpress/386/Wildcat! v1.3
---------------
* Origin: MADDOG! BBS : (510) 895-8089 : San Leandro, Ca. (1:215/13)

SOURCE: echomail via exec-pc

Email questions or comments to sysop@ipingthereforeiam.com
All parts of this website painstakingly hand-crafted in the U.S.A.!
IPTIA BBS/MUD/Terminal/Game Server List, © 2025 IPTIA Consulting™.