Ascend Archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: (ASCEND) P75 and X2 [digital pad?]
RE:
>From: Jeff_Powell@ascend.com
>To: kevin@ascend.com
>cc: Km@Mathcs.Emory.Edu, Ascend-Users@Max.Bungi.Com
>Date: Wed, 28 May 1997 17:56:11 -0700
>Subject: Re: (ASCEND) P75 and X2 [digital pad?]
>
>
>I'll just through my 2bits in here.
>
>Testing with several K56 modems through the POTS jack on a P25 and a P75
>AND a "normal" POTS line showed little variance in results; if anything,
>connections through the Pipelines were 1 or 2 steps better.
>
>HOWEVER.... when going through the pipeline, the AT&V1 command will show
>"digital pad detected". The K56 modems KNOW if they are going through an
>pipeline-like device and will add 6dBm to their output when they detect
>such a unit. I have NO idea if USR can or does do the same thing; perhaps
>they do with a "real" X2 modem...
>
>I, personally, wouldn't worry about this without testing with a real X2
>modem first......
>
This was an indirect response to my posting noting that USR's test
line testing my P75 pots port said that it was X2 capable but to
expect degraded performance. This test is done without using an
actual X2 modem.
Well, I went ahead and borrowed a real X2 modem to do a real test.
The result actually agreed quite well with the prediction.
I made a series of X2 connections to an X2 server, and then terminated
the connection after a few seconds. Then I issued the ATI6 command
to see the receive rate. Running through the P75 I got 37.3K every time.
I didn't have an analog to compare with, but I did plug my ISDN line
into an IBM 7845 NT1+Pots, and test the X2 again using that POTS.
This time I consistantly got 46.6K.
Incidentally, I found the X2 receive rate that the USR reports in the
CONNECT command is always considerably higher than what ATI6 shows.
Apparently the CONNECT command prints before the complete negotiation
is done. The connect command reported 48K for the P75, and 53K against
the IBM.
There is no indication in the documentation that comes with the
modem of any provision for digital pads. I looked through all the
documented commands and S registers and didn't see one that looked
relevant.
Ken Mandelberg | km@mathcs.emory.edu
Emory University |
Dept of Math and CS | Phone: Voice (404) 727-7963
Atlanta, GA 30322 | FAX 727-5611
++ Ascend Users Mailing List ++
To unsubscribe: send unsubscribe to ascend-users-request@bungi.com
To get FAQ'd: <http://www.shore.net/~dreaming/ascend-faq>
or <ftp://ftp.shore.net/members/dreaming/ascend-faq.txt>