NetComm AM5698 Network Router User Manual


 
Rev.1 - YML658 www.netcomm.com.au
AM5698 Roadster V.92 User Guide Page 27
Does V.92 "QuickConnect" work on all calls?
This feature of the V.92 standard allows the modem to "learn" and "remember" the
variables associated with calling a specific telephone number and connecting to a
specific modem associated with that number. This feature will be most effective when
you repetitively call the same number - such as that for your on-line service or internet
service provider. The modem will then be able to use its stored profile and deliver the
advantage of a quicker connection.
Does V.44 work equally well on all file transfers? Which are most
improved; least improved?
V.44 compression is optimized for the types of files associated with internet use
including web pages, graphics and documents such as .PDF files. As with all
compression the amount of improved performance varies both with the actual format
and with the content of individual pages. For reference, web searches show the most
visible improvement, especially searches on web stores or areas that have high
amounts of text and numerous small images. The next most improvement is in standard
web browsing. Email and downloading of ASCII type text files show noticeable but
more modest improvement
Will a V.92 modem work automatically with earlier modems? V.90,
K56flex, X2? With 33.6k, 14.4k, 9600 and 2400 modems?
A V.92 modem will automatically negotiate and connect at the best achievable-shared
speed down to 2,400 bps. The negotiation and the related connection time may take
longer if the connection does need to be negotiated down to a very low speed as the
higher speeds are attempted first. However the connection between a 56K V.92 and a
56K V.90 will take approximately the same time as between two current V.90 modems.
How do V.92 modem speeds compare to ISDN, ADSL and Cable speeds?
First, remember that V.92 is asymmetric in nature, the same as ADSL. It offers download
speeds from the web which are higher than it's upload speeds. This means that it is
inherently different from ISDN and has been optimized, like ADSL, for Internet access.
In fact it is optimized primarily with V.44 compression rather than with purely higher
transmission speed as found in ADSL and Cable. Because of this it is not possibly to
directly compare the different devices except in terms of the Internet experience itself,
including Web browsing. Given optimum V.92/V.44 performance of approximately
300,000 bps, this still means that that it will operate at less than half the speed of most
broadband services (which range from 600,00 bps to 1,500,000 bps).