Inferior connection with Spirit Magnum V.92 modem

[Netocrat]

I'm unable to connect to my current ISP and was also unable to connect
to my former ISP at V.90 56k with my external Spirit Magnum V.92 modem
which supposedly supports this speed connection. The fastest I can
connect is 50666. I know that the ISP supports 56k as I have connected
to it at that speed on other computers.

Does anyone know whether this modem is up to the job? Are there some
special initialisation strings I should be using?

As far as I can tell this modem is a local Australian one so presumably
this question is aimed at compatriots - but I may be wrong in this.

I'm on a Pentium 4 with 16550A UART running Gentoo linux.

 

[Shep©]

I'm unable to connect to my current ISP and was also unable to connect
to my former ISP at V.90 56k with my external Spirit Magnum V.92 modem
which supposedly supports this speed connection. The fastest I can
connect is 50666. I know that the ISP supports 56k as I have connected
to it at that speed on other computers.

Does anyone know whether this modem is up to the job? Are there some
special initialisation strings I should be using?

As far as I can tell this modem is a local Australian one so presumably
this question is aimed at compatriots - but I may be wrong in this.

I'm on a Pentium 4 with 16550A UART running Gentoo linux.

You are unlikely to ever connect at 56K as the V90 protocol had a max
limit of 53k download.It's so little of a difference I wouldn't worry
and there are plenty of people in rural areas who can still only get
33k on a good day!

 

[Netocrat]

You are unlikely to ever connect at 56K as the V90 protocol had a max
limit of 53k download.It's so little of a difference I wouldn't worry
and there are plenty of people in rural areas who can still only get
33k on a good day!

It's not a big deal but I'd like to know why this modem doesn't connect
at the same rate as other modems. I certainly appreciate the speed I
have now and don't particularly need any faster, but it's irking me that
an advertised capability of this modem is not realised in practice when
it there is nothing on the other side to prevent it.

Actually the V90 protocol has a limit of 56k, but according to
http://www.v90.com/whatis.htmhttp://www.v90.com/whatis.htm, the FCC in
the USA limits power levels so it can only reach 54K... I don't know if
this is true as I don't live in the USA. This isn't the case in
Australia - I have personally witnessed connect messages stating 56000.
To my current ISP. Just not with this modem. Why not?

 

[Shep©]

It's not a big deal but I'd like to know why this modem doesn't connect
at the same rate as other modems. I certainly appreciate the speed I
have now and don't particularly need any faster, but it's irking me that
an advertised capability of this modem is not realised in practice when
it there is nothing on the other side to prevent it.

Actually the V90 protocol has a limit of 56k, but according to
http://www.v90.com/whatis.htmhttp://www.v90.com/whatis.htm, the FCC in
the USA limits power levels so it can only reach 54K... I don't know if
this is true as I don't live in the USA. This isn't the case in
Australia - I have personally witnessed connect messages stating 56000.
To my current ISP. Just not with this modem. Why not?

You link doesn't work for me but this is better page IMHO,
http://www.modemsite.com/56k/what56.asp

also as you can see initial connection rates are not all the story
with modems and should not be take too seriously.It's only a number
and not an accurate one at that :O

 

[Netocrat]

It's not a big deal but I'd like to know why this modem doesn't connect
at the same rate as other modems. I certainly appreciate the speed I
have now and don't particularly need any faster, but it's irking me that
an advertised capability of this modem is not realised in practice when
it there is nothing on the other side to prevent it.

Actually the V90 protocol has a limit of 56k, but according to
http://www.v90.com/whatis.htmhttp://www.v90.com/whatis.htm, the FCC in
the USA limits power levels so it can only reach 54K... I don't know if
this is true as I don't live in the USA. This isn't the case in
Australia - I have personally witnessed connect messages stating 56000.
To my current ISP. Just not with this modem. Why not?

Well I've done a few download tests and it seems the modem only sustains
about 3.9 kilobytes per second, so obviously the speed is being
downgraded even further after connect. Line quality probably having
some effect and I'm still dubious about the quality of the modem itself
- as I say, other modems connect at a higher initial speed to the same
ISP. Then again, I didn't check their subsequent download rates...
perhaps they likewise downgraded.

Anyway, I'm not going to concern myself further about it - like you say,
it's little difference. It's a reliable connection and 3.9 kps is
plenty - I still remember borrowing a relative's 28.8k modem when they
were the hottest new thing and it was like driving on the autobahn.

 

[Shep©]

Well I've done a few download tests and it seems the modem only sustains
about 3.9 kilobytes per second, so obviously the speed is being
downgraded even further after connect. Line quality probably having
some effect and I'm still dubious about the quality of the modem itself
- as I say, other modems connect at a higher initial speed to the same
ISP. Then again, I didn't check their subsequent download rates...
perhaps they likewise downgraded.

Anyway, I'm not going to concern myself further about it - like you say,
it's little difference. It's a reliable connection and 3.9 kps is
plenty - I still remember borrowing a relative's 28.8k modem when they
were the hottest new thing and it was like driving on the autobahn.

I have an old ISA 33k full hardware modem somewhere.Was a great modem
for online gaming.A lot of modem modems are not that good IMHO.I would
suspect yours is a good one as it's an External and may be full
hardware.

 

[kony]

It's not a big deal but I'd like to know why this modem doesn't connect
at the same rate as other modems. I certainly appreciate the speed I
have now and don't particularly need any faster, but it's irking me that
an advertised capability of this modem is not realised in practice when
it there is nothing on the other side to prevent it.

Actually the V90 protocol has a limit of 56k, but according to
http://www.v90.com/whatis.htmhttp://www.v90.com/whatis.htm, the FCC in
the USA limits power levels so it can only reach 54K... I don't know if
this is true as I don't live in the USA. This isn't the case in
Australia - I have personally witnessed connect messages stating 56000.
To my current ISP. Just not with this modem. Why not?

In certain situations (I forget the exact scenarios, perhaps
an inappropriate or poor driver) the connect speed is
reported as the speed of the UART rather than actual modem
speed. I wonder if it was @ 56000, rather than the
modem(s). Regardless, if you had 50K, 3.9 K/s download is
still too slow, it does appear there is some other problem
though I don't know what.

 

[Shep©]

In certain situations (I forget the exact scenarios, perhaps
an inappropriate or poor driver) the connect speed is
reported as the speed of the UART rather than actual modem
speed. I wonder if it was @ 56000, rather than the
modem(s). Regardless, if you had 50K, 3.9 K/s download is
still too slow, it does appear there is some other problem
though I don't know what.

Good call.It was common for people to believe they had connected at
115,000 because of a bad or incorrect firmware/.inf file install.

 

[Netocrat]

Good call.It was common for people to believe they had connected at
115,000 because of a bad or incorrect firmware/.inf file install.

Well that could be the case. Like I said, I didn't test the subsequent
download speed of the other modem after connection. Who knows what the
actual transfer rate became?

However I have used a few different 56K modems on PCs I own/ed and those
of my folks' PC at other times and I know that I've had sustained
transfers of around 6 kilobytes per second - obviously using
compression. This modem just won't go near that. I've recently moved
from a large-ish city to a small rural town so that could explain part
of the problem, but even in the city I connected to the same ISP and it
was never at the same rate as the other modem that I tested connecting
to the same ISP - although I emphasise again that I didn't test data
rates subsequent to connection and again your pondering whether the
speed reported was between modem and serial port rather than modem and
ISP is valid, but I really doubt it.

 

[kony]

Good call.It was common for people to believe they had connected at
115,000 because of a bad or incorrect firmware/.inf file install.

Thing is, I'm not sure it'd report as 56000, probably 57600
if that were the issue, which is roughly 56K but
insufficient info to be sure OP translated the figure from
bits to kilobits.

 

[Ed Medlin]

Well that could be the case. Like I said, I didn't test the subsequent
download speed of the other modem after connection. Who knows what the
actual transfer rate became?

However I have used a few different 56K modems on PCs I own/ed and those
of my folks' PC at other times and I know that I've had sustained
transfers of around 6 kilobytes per second - obviously using
compression. This modem just won't go near that. I've recently moved
from a large-ish city to a small rural town so that could explain part
of the problem, but even in the city I connected to the same ISP and it
was never at the same rate as the other modem that I tested connecting
to the same ISP - although I emphasise again that I didn't test data
rates subsequent to connection and again your pondering whether the
speed reported was between modem and serial port rather than modem and
ISP is valid, but I really doubt it.

I live in a very rural area and before DSL was available I would get all
kinds of different speed readings from various modems. Some would report
56.6k (max I ever saw) which was actually a firmware glitch, and others from
27 to 33k. Try www.pcpitstop.com and run their speed tests and see what you
are actually getting. It is a free test and they have a lot of other tests
you can run there that are informative. Even my DSL is marginal as I am at
the very end of the line as far as availability goes. Supposed to be at a
gig, but I get only about 350k DL and 450k UL speeds on a good day. I am
happy to have all I can get.......

Ed

 

[Giovanni]

I'm unable to connect to my current ISP and was also unable to connect
to my former ISP at V.90 56k with my external Spirit Magnum V.92 modem
which supposedly supports this speed connection. The fastest I can
connect is 50666. I know that the ISP supports 56k as I have connected
to it at that speed on other computers.

I'm on a Pentium 4 with 16550A UART running Gentoo linux.

50666 ip probably the fastest speed that your modem finds compatible for
your telephone line.

Ciao
Giovanni

 

[Netocrat]

I live in a very rural area and before DSL was available I would get all
kinds of different speed readings from various modems. Some would report
56.6k (max I ever saw) which was actually a firmware glitch, and others from
27 to 33k. Try www.pcpitstop.com and run their speed tests and see what you
are actually getting. It is a free test and they have a lot of other tests
you can run there that are informative. Even my DSL is marginal as I am at
the very end of the line as far as availability goes. Supposed to be at a
gig, but I get only about 350k DL and 450k UL speeds on a good day. I am
happy to have all I can get.......

Ed

The test says I'm getting 29 kilobits per second. That works out at
about 3.5 kilobytes per second, which is close to what I tested with an
ftp download. It's a long way from what the modem reported on
connection - 49333 bits per second.

 

[Netocrat]

50666 ip probably the fastest speed that your modem finds compatible for
your telephone line.

Maybe but I've connected faster to the same ISP with other modems...

 

[Shep©]

The test says I'm getting 29 kilobits per second. That works out at
about 3.5 kilobytes per second, which is close to what I tested with an
ftp download. It's a long way from what the modem reported on
connection - 49333 bits per second.

Thus proving that the initial connection figure is next to useless :/

 

[Quaoar]

Maybe but I've connected faster to the same ISP with other modems...

You are still missing the point that Shep has been trying to get across:
initially reported connection speed is generally an unreliable number
and will vary modem to modem. Initially reported speed often has little
relationship to actual sustainable download speed. The only way to
verify what you believe about your curren and previous modems is to do
repeated download tests with each from the same source.

 

[haphzrd]

I'm unable to connect to my current ISP and was also unable to connect
to my former ISP at V.90 56k with my external Spirit Magnum V.92 modem
which supposedly supports this speed connection. The fastest I can
connect is 50666. I know that the ISP supports 56k as I have connected
to it at that speed on other computers.

Does anyone know whether this modem is up to the job? Are there some
special initialisation strings I should be using?

As far as I can tell this modem is a local Australian one so presumably
this question is aimed at compatriots - but I may be wrong in this.

I'm on a Pentium 4 with 16550A UART running Gentoo linux.

In Canada and the US, modem speeds over telephone lines are regulated to
53kbit/s and typically that maximum is closer to 50 kbit/s.

 

[Netocrat]

You are still missing the point that Shep has been trying to get across:
initially reported connection speed is generally an unreliable number
and will vary modem to modem. Initially reported speed often has little
relationship to actual sustainable download speed. The only way to
verify what you believe about your curren and previous modems is to do
repeated download tests with each from the same source.

I can't do any tests with other modems at the moment so I can't make any
comparisons. Short of someone with experience with the same modem telling
me something specific about it, I'll reserve judgement.

 

[Netocrat]

Well I've done a few download tests and it seems the modem only sustains
about 3.9 kilobytes per second, so obviously the speed is being
downgraded even further after connect. Line quality probably having
some effect and I'm still dubious about the quality of the modem itself
- as I say, other modems connect at a higher initial speed to the same
ISP. Then again, I didn't check their subsequent download rates...
perhaps they likewise downgraded.

Anyway, I'm not going to concern myself further about it - like you say,
it's little difference. It's a reliable connection and 3.9 kps is
plenty - I still remember borrowing a relative's 28.8k modem when they
were the hottest new thing and it was like driving on the autobahn.

OK, a bit of positive follow-up - results have changed since my initial
postings. Things seem to be fairly variable. Right now I have a reported
connection string of 50666. I have written a small KDE Panel applet that
has a graph and queries the ppp interface for stats. I'm downloading using
gtk-gnutella with several concurrent sources so the connection is
saturated.

The current 15-minute average is 5722 bytes per second which is equivalent
to 45776 bits per second.

A short while ago, however, my 15-minute average was 8470 bytes per second,
equivalent to 67760 bits per second. I had 1 or 2 second bursts of a lot
more, including a maximum of 12850 bytes per second (102800 bits per
second, pretty close to the maximum 115200 of my UART port).

So my problem is obviously not that the modem can't operate at high rates,
and the comments by posters that initial connection string is somewhat
irrelevant are spot on - considering that with a very similar connection
string I've had subsequent sustained transfer rates that are so far apart
that one is more than twice the other (earlier in the thread I reported an
ftp download of 3.9 kilobytes per second - 31948 bits per second - and the
http://www.pcpitstop.com test returned 29 kilobits per second - 29696 bits
per second).

So to summarise:
Date Connect Test Speed (bits per second)
25/5/2005 50666 ftp download 31948
26/5/2005 49333 pcpitstop 29696
04/6/2005 50666 gnutella dnld 45776
04/6/2005 50666 gnutella dnld 67760

I won't focus on the spikes, but the average of 67760 bits per second is
well above the reported connection speed of 50666 and well above even the
theoretical maximum of 56000 bits per second. I'm assuming that
compression plays a major part in this.

I'm also not sure how stop bits and the like relate to reported rates. If
the modem reports that it is connected at 50666, does this mean that it
will transfer my user-data of x bytes in (x * 8) / 50666 seconds, or will
it add stop/start bits or other gunk so that the actual transfer time of my
x bytes becomes (x * (8 + y)) / 50666 seconds, where y is the number of
start/stop/other bits added, or some other similar formula? I'm ignoring
compression.

If the second is true, then connect rates don't really represent
user-transfer rates and are actually over-inflated, so assuming a single
stop bit, and that my second formula is accurate, a reported speed of 50666
would actually concur with an experienced speed of 8/9 * 50666, or 45036.
That could be another reason why connect strings do not match experienced
speeds.