[news.admin] G versus Zmodem

jeffery@jsheese.FIDONET.ORG (Jeff Sheese) (05/21/89)

In an article of <20 May 89 06:55:02 GMT>, scott@clmqt.UUCP (Scott Reynolds)  
writes:

 >My xferstats file shows some interesting figures.  On a direct dial 2400
 >baud connection, average transfer rate (for files of at least 5K or 
 >bigger) is 193 cps.  On a clean line, G will actually do up to about 222
 >cps, believe it or not!  Compare this to my best ZModem times of 231 cps
 >and not one character higher, ever.  I average 226 cps on ZModem transfers.
 >On a 1200 baud connection through a packet switched network to an 
 >Internet gateway to the host, I get 93 cps on average.  Best conditions
 >yield up to about 109 cps, but that happens extremely rarely.

Using Binkleyterm (a Fidonet mailer for MSDOS machines - read *not* IBM  
dependant) I average around 235-240 cps at 2400 baud.  It has it's own bult-in  
zmodem implementation.  Source code is available from choice Fidonet systems.   
Send mail if interested, I can tell you where to find it or even post the  
source to c.b.i.p.  It's a mailer program that supports file attaches, file  
requests, even file update requests.  It's really remarkable what features it  
supports.  Since it's written in C it could very easily be ported to *nix.  It  
uses the FOSSIL concept, which really is a method of using medium level calls  
to a communications interface written solely for the hardware your using.   
FOSSIL specs are public domain.

 >G is indeed streaming (watch it go when you are connected through a 
 >packet network if you don't believe me) but the one thing that really
 >slows it down is poor error recovery.  If in mid transfer a block is short
 >a few characters, the receiver will time out after a fairly long period
 >of time.

For sure.  If I turn my modem off during a D.* transfer, the next time I make  
the uucp connection the whole thing is transferred again.  Now G may be the  
basic downward compatible standard of Usenet, but the gurus aught to consider  
zmodem in a few experimental implementations.  I've used bimodem a few times,  
which allows for zmodem bidirectional transfers.  Imagine, transferring all  
your mail to it's destination while getting the mail/news from the same site  
at the same time.
--  
Jeff Sheese - via FidoNet node 1:109/116
UUCP: ...!netsys!jsheese!jeffery
ARPA: jeffery@jsheese.FIDONET.ORG
(I am sole owner.  My opinions represent my company.)
(Send all flames to null@jsheese.Fidonet.ORG)

benton@VAX1.CC.UAKRON.EDU (Kevin Benton) (05/24/89)

In article <112.2475C03A@jsheese.FIDONET.ORG> jeffery@jsheese.Fidonet.ORG writes:
>In an article of <20 May 89 06:55:02 GMT>, scott@clmqt.UUCP (Scott Reynolds)  
>writes:
>
> >My xferstats file shows some interesting figures.  On a direct dial 2400
> >baud connection, average transfer rate (for files of at least 5K or 
> >bigger) is 193 cps.  On a clean line, G will actually do up to about 222
> >cps, believe it or not!  Compare this to my best ZModem times of 231 cps

>Using Binkleyterm (a Fidonet mailer for MSDOS machines - read *not* IBM  
>dependant) I average around 235-240 cps at 2400 baud.  It has it's own bult-in  
>zmodem implementation.  Source code is available from choice Fidonet systems.   
>Send mail if interested, I can tell you where to find it or even post the  

<much removed>

If someone will send me a copy of a public domain uucp with source, that is
well commented, I'd be happy to add a Z protocol, and a "K" protocol, one of
my own bi-directional protocols that basically runs Zmodem both ways, but
but somewhat better than bi-modem.

kb