Re: [hylafax-users] large multiport systems

["Darren Nickerson" <darren.nickerson@ifax.com>]

Lee,

Could you also reply to the other part of my email? In particular:

1. What hardware are you using to collect your real-world V.34 statistics?
2. Are you sure this hardware actually implements V.8 fast handshaking?

-Darren

--
Darren Nickerson
Senior Sales & Support Engineer
iFax Solutions, Inc. www.ifax.com
darren.nickerson@ifax.com
+1.215.438.4638 office
+1.215.243.8335 fax

----- Original Message ----- 
From: "Lee Howard" <faxguy@howardsilvan.com>
To: "Darren Nickerson" <darren.nickerson@ifax.com>
Cc: <jlewis@lewis.org>; <hylafax-users@hylafax.org>
Sent: Saturday, August 23, 2003 7:39 PM
Subject: Re: [hylafax-users] large multiport systems


> On 2003.08.23 13:25 Darren Nickerson wrote:
> > 
> > > > You're not up to date on deployment statistics ... V.34 is much
> > more
> > > > common
> > > > than that. It's estimated that about 60% of all laser fax machines
> > and
> > > > 25%
> > > > of inkjet models sold today are V.34 enabled. By 2005, as much as
> > 75%
> > > > of all
> > > > laser fax machines and 50% of all inkjet fax machines sold will be
> > > > V.34
> > > > enabled.
> > >
> > > In my experience V.8 handshaking (done with V.34 faxing) takes
> > longer
> > > than handshaking with non-V.34 faxing.  And therefore V.34 only
> > proves
> > > beneficial if there is enough data to send that the increased
> > bitrate
> > > will compensate for the V.8 handshaking lag.  Generally speaking a
> > > one-page MMR-compressed page, such as this gentlemen is discussing,
> > > will not contain enough data to make V.34 worthwhile.
> > 
> > Lee,
> > 
> > That has not been our experience, and it's a surprising observation
> > since I
> > think V.8's entire reason for existing is to make handshaking faster,
> > not
> > slower.
> 
> Ah.  I've miscommunicated.  I didn't mean to imply any conclusion on 
> V.8 technology for a single call, but rather as a whole for single-page 
> bulk faxing.  Allow me to restate...
> 
> In my experience the total time consumed with handshaking for a group 
> of faxes to random, uncontrolled locations will take longer when using 
> V.8 handshaking (done with V.34 faxing) than if handshaking with 
> non-V.34 faxing were done.  And therefore V.34 only proves beneficial 
> if there is enough total data to send among the group of faxes to 
> V.34-capable destinations that the increased bitrate will compensate 
> for the V.8 handshaking lag to non-V.34-capable destinations.  
> Generally speaking a one-page MMR-compressed page (all V.34-capable 
> receivers *should* support MMR due to the common ECM prerequisite 
> hurdle), such as this gentlemen is discussing, will not contain enough 
> data to make V.34 worthwhile.
> 
> So, I don't mean to make a statement regarding how long handshaking 
> takes when a V.34-capable sender calls a V.34-capable receiver versus 
> how long handshaking takes when a non-V.34-capable sender calls a 
> non-V.34-capable receiver, but rather I mean to say that the total 
> "wasted" time trying to perform V.8 handshaking when a V.34-capable 
> sender calls non-V.34-capable receivers may not be less than the time 
> savings for those instances when the receivers are V.34-capable.
> 
> When a V.34-capable sender calls it first tries to initiate V.8 
> communication (required for all data communication speeds faster than 
> 14,400 bps).  If that fails then it falls back to V.21.  That fallback 
> takes some time.  If the modem spends some seconds before falling back 
> to V.21, then in order for V.34 use to be worthwhile it needs to more 
> than "make up" those seconds with another call to a V.34 capable 
> receiver.  Most V.34 connections aren't going to be at 33,600 bps, and 
> will probably average at 28,800 bps.  So, more than 1800 bytes of data 
> will need to be sent at V.34 for every second wasted in failed V.8 
> connection attempts.
> 
> How long does a modem spend trying to do V.8?  I don't know.  Yes, it 
> probably varies from implementation to implementation; however, my 
> statement is to say that it takes *some* time.  I don't pretend to know 
> the reason for V.8's entire existence.  What I do know is that in my 
> experience there is more time consumed in attempting V.8 handshaking 
> with all destinations than is generally saved by V.34 data speeds to 
> those that do support it.  Now, if the amount of data or the percentage 
> of V.34-capable receivers out there goes up, then the chances of V.34 
> proving beneficial are increased.  This should be true for *any* 
> implementation.
> 
> V.34 communication should only be attempted with any single destination 
> if it is known to support it or if the amount of image data to send is 
> sufficient to make it worthwhile.  Currently HylaFAX cannot make this 
> determination, unfortunately.
> 
> Lee.
> 

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