[cisco-nas] v90 vs v92

[Pierre Nepveu]

thanks Aaron. Excellent, as per your usual. 

Exactly what I needed.

pn
cd /pub; more beer


Le 2004-03-16 à 13:05, Aaron Leonard a écrit:

AL> > hi all,
AL> 
AL> > quick question, if I may.
AL> 
AL> > we have a bunch of v.90 modems in AS-5200's. Is there any clear advantage to
AL> > buying new boxes ?
AL> 
AL> If you're only interested in doing dialup modem stuff, then the
AL> main advantage to newer boxes is that the AS5200s are dead-ended
AL> featurewise in 12.1/12.1AA - so with newer boxes you can run current IOS.
AL> 
AL> > What's up with v.92
AL> > - is PCM upstream implemented yet ?
AL> > - what is the volume of client v.92 modems out there ?
AL> 
AL> Here's the scoop with the newer modem protocols ...
AL> 
AL> - compression
AL>   V.44 really is (somewhat) better than V.42bis.  With NextPort
AL>   platforms (AS5350/AS5400/AS5850) you can get as much as 400k
AL>   throughput with highly compressible data over V.44 over a modem
AL>   call.  MICA platforms are limited to around 200k and Microcom
AL>   56k modems are limited to 92k.  (Of course, most big data that
AL>   Internet users download tends to be pre-compressed, in which
AL>   case performance would be basically the same with Microcom vs.
AL>   MICA vs. NextPort.)
AL> 
AL> - V.92
AL>   - We (still) don't support PCM upstream.  The evidence from the
AL>   few vendors/sites that have implemented PCM upstream is that it
AL>   doesn't actually add any net improved performance.
AL>   - V.92 Quick Connect does however add a real improvement in 
AL>   training time, and is widely implemented
AL>   - V.92 Modem on Hold does work
AL> 
AL> Aaron
AL>