enger@seka.scc.com (Robert M. Enger) (01/14/91)
Folks: In one of the many excellent articles posted to this group, it was stated that USR provides a Fall-FORWARD capability (to restore a link to higher speed after a line impairment has ceased). The author mentioned that this Fall-FORWARD capability was PROPRIETARY to USR. DOES ANYONE KNOW WHAT THE V.32bis STANDARD ACTUALLY SAYS WITH REGARD TO FALL-BACK/FORWARD? Is there a *real* standard for Fall-FORWARD? Has USR promised to upgrade/migrate to the standard (if it exists)? Thanks, Bob Enger enger@seka.scc.com
lstowell@pyrnova.pyramid.com (Lon Stowell) (01/15/91)
In article <1991Jan14.021653.1194@europa.asd.contel.com> enger@seka.scc.com writes: >Folks: > >The author mentioned that this Fall-FORWARD capability was >PROPRIETARY to USR. > >DOES ANYONE KNOW WHAT THE V.32bis STANDARD ACTUALLY SAYS >WITH REGARD TO FALL-BACK/FORWARD? > Any V.32 modem can request a retrain at any time. All you have to do is request the higher rate in the subsequent training sequence. There is at least one other modem vendor that will go back to a higher rate after having previously dropped to a lower one. The implementation IF PROPRIETARY explicitly means that the modem implementing same IS NOT V.32 COMPLIANT--as proprietary and compliant are mutually exclusive!!! I have heard the ability to increase rate referred to a "Gearshift" mode, but cannot recall if this is a trademarked term or a generic one... BTW, the one other vendor I know of dropped the feature, as typically the retrain to shift rates took more time, on a typical call, than continuing at the lower rate would...i.e. the MODEM is not the best place to figure out if toll charges for a specific call would be best minimized by hanging up and trying for another circuit...