Mailing List Archive

> hi all,

> quick question, if I may.

> we have a bunch of v.90 modems in AS-5200's. Is there any clear advantage to
> buying new boxes ?

If you're only interested in doing dialup modem stuff, then the
main advantage to newer boxes is that the AS5200s are dead-ended
featurewise in 12.1/12.1AA - so with newer boxes you can run current IOS.

> What's up with v.92
> - is PCM upstream implemented yet ?
> - what is the volume of client v.92 modems out there ?

Here's the scoop with the newer modem protocols ...

- compression
V.44 really is (somewhat) better than V.42bis. With NextPort
platforms (AS5350/AS5400/AS5850) you can get as much as 400k
throughput with highly compressible data over V.44 over a modem
call. MICA platforms are limited to around 200k and Microcom
56k modems are limited to 92k. (Of course, most big data that
Internet users download tends to be pre-compressed, in which
case performance would be basically the same with Microcom vs.
MICA vs. NextPort.)

- V.92
- We (still) don't support PCM upstream. The evidence from the
few vendors/sites that have implemented PCM upstream is that it
doesn't actually add any net improved performance.
- V.92 Quick Connect does however add a real improvement in
training time, and is widely implemented
- V.92 Modem on Hold does work

Aaron

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>