Subject: RE: (usr-tc) ****SOLVED***** Websites failing on TCHub vs Ascend... Where to start?

From: Sonny Ruiz <[email-masked]>
Date: Sun, 12 Mar 2000 05:56:01 +0000

May be it has something to do with the fact that 1518 is the max MTU 
permited by ethernet and many sites might have it as the default MTU.

Sonny
>From: "Robb Bryn" <[email-masked]>
>Reply-To: [email-masked]
>To: <[email-masked]>
>Subject: RE: (usr-tc) ****SOLVED***** Websites failing on TCHub vs 
>Ascend... Where to start?
>Date: Fri, 10 Mar 2000 16:59:52 -0500
>
>I started at 1514 per Source Technology's recommendation and found that 
>1514
>fixed "most" of the problems, began incrementing by 4 until it worked on 
>all
>sites, ended at 1518.
>
>Thanks
>Robb Bryn
>
> > -----Original Message-----
> > From: [email-masked]
> > [mailto:[email-masked]]On Behalf Of Randy McMillan
> > Sent: Friday, March 10, 2000 5:12 PM
> > To: [email-masked]
> > Subject: Re: (usr-tc) ****SOLVED***** Websites failing on TCHub vs
> > Ascend... Where to start?
> >
> >
> > How did you decide on 1518 for the MTU size?
> >
> > Randy McMillan
> > PacInfo
> >
> > ----- Original Message -----
> > From: Robb Bryn <[email-masked]>
> > To: <[email-masked]>
> > Sent: Friday, March 10, 2000 11:12 AM
> > Subject: (usr-tc) ****SOLVED***** Websites failing on TCHub
> > vs Ascend...
> > Where to start?
> >
> >
> > > Problem Solved...
> > > As everyone suspected - it was an MTU problem.  More specifically a
> > problem
> > > in the MTU size.  Setting the MTU size to 1500 via Radius
> > did NOT fix the
> > > problem.  After a few enlightening words from the folks at Source
> > > Technology, and the comments received via this list, I set
> > the MTU size to
> > > 1518 in Radius AND on the Default user in the ARC itself.
> > Everything now
> > > works flawlessly.
> > >
> > > I appreciate everyone's help.
> > >
> > > Thanks
> > > Robb Bryn
> > >
> > >
> > >
> >
> >
> > -
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>
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---

From: Andrey Zimin <[email-masked]>
Date: Sun, 12 Mar 2000 11:54:43 +0000

Hi all!

Anybody know what settings I need on HiperDSP(2.0.51) for delay modem
answer on 3sec?

As I read in documenation s0 register can`t supported and must be set in 0... :-((

Thank for advice!

Good luck !
======================
 Andrey Zimin | AVZ7-RIPE
           MTU-Intel ISP
        Moscow, Russia
======================

-

---

From: Andrey Zimin <[email-masked]>
Date: Sun, 12 Mar 2000 11:54:43 +0000

Here INFO0 sequince I recive from HperDSP (from 12bit) -21FD.

As defned in ITU-V34:
===
10.1.2.3.3 INFO0 information bits
Table 14 defines the bits in the INFO0 sequences. Bit 0 is transmitted first.

TABLE  14/V.34
Definition of bits in INFO0 sequences

INFO0 bits
LSB:MSB Definition
0:3 Fill bits: 1111
4:11 Frame sync: 01110010, where the left-most bit is first in time
12 Set to 1 indicates symbol rate 2743 is supported
13 Set to 1 indicates symbol rate 2800 is supported
14 Set to 1 indicates symbol rate 3429 is supported
15 Set to 1 indicates the ability to transmit at the low carrier frequency with a symbol rate of 3000
16 Set to 1 indicates the ability to transmit at the high carrier frequency with a symbol rate of 3000
17 Set to 1 indicates the ability to transmit at the low carrier frequency with a symbol rate of 3200
18 Set to 1 indicates the ability to transmit at the high carrier frequency with a symbol rate of 3200
19 Set to 0 indicates that transmission with a symbol rate of 3429 is disallowed
20 Set to 1 indicates the ability to reduce transmit power to a value lower than the nominal setting
21:23 Maximum allowed difference in symbol rates in the transmit and receive directions. With the symbol rates labelled in
increasing order, where 0 represents 2400 and 5 represents 3429, an integer between 0 and 5 indicates the difference allowed in
number of symbol rate steps
24 Set to 1 in an INFO0 sequence transmitted from a CME modem
25 Set to 1 indicates the ability to support up to 1664 point signal constellations
26:27 Transmit clock source: 0 = internal, 1 = synchronized to receive timing, 2 = external, 3 = reserved for ITU
28 Set to 1 to acknowledge correct reception of an INFO0 frame during error recovery
29:44 CRC
45:48 Fill bits: 1111
NOTES
1 - Bits 12 through 14 are used to indicate the modem's capabilities and/or configuration. The values of bits 15 through 20 depend
upon regulatory requirements and apply only to the modem's transmitter.
2 - Bit 24 may be used in conjunction with the GSTN access category octet defined in Recommendation V.8 to determine the optimum
parameters for the signal convertors and error-control functions in the call and answer modem and any intervening CME.
======

Anybody know why?
S54=64 on HiperDSP
=====
mdm1> ati4

Modem Current Settings

   E0  Q1  V0  X0
   &A1  &G0  &K1  &M4  &N0  &U0  %B7
   *U1=1  *U2=0  *U3=1  *V2=0  *X0=2048  *X1=2

   S00=001  S01=000  S02=043  S03=013  S04=010  S05=008  S06=002  S07=060
   S08=002  S09=006  S10=007  S11=070  S12=050  S13=000  S14=001  S15=000
   S16=000  S17=000  S18=000  S19=000  S20=000  S21=000  S22=000  S23=000
   S24=000  S25=000  S26=000  S27=000  S28=008  S29=020  S30=000  S31=000
   S32=000  S33=000  S34=000  S35=000  S36=000  S37=000  S38=000  S39=012
   S40=000  S41=000  S42=000  S43=000  S44=000  S45=000  S46=000  S47=000
   S48=000  S49=016  S50=100  S51=064  S52=005  S53=000  S54=064  S55=000
   S56=000  S57=000  S58=000  S59=000  S60=000  S61=000  S62=000  S63=000
   S64=000  S65=000  S66=000  S67=001  S68=000  S69=000  S70=000  S71=000
   S72=000  S73=001  S74=000  S75=000  S76=000  S77=000  S78=000  S79=000
   S80=000  S81=000  S82=012

   Last Dialed #:
======

Good luck !
======================
 Andrey Zimin | AVZ7-RIPE
           MTU-Intel ISP
        Moscow, Russia
======================

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---

From: Mike Andrews <[email-masked]>
Date: Sun, 12 Mar 2000 20:29:48 +0000

>From the ATS$ command:

S54 Bit Mapped
      1 = Disable 2400 symbol rate
      2 = Disable 2743 symbol rate
      4 = Disable 2800 symbol rate
      8 = Disable 3000 symbol rate
     16 = Disable 3200 symbol rate
     32 = Disable 3429 symbol rate
     64 = Disable V.8 Call Indicate
    128 = Disable V.8 Mode

so s54=64 should enable all symbol rates.  I don't think there's a
*direct* relationship between the S54 register and anything in the v.34
spec.

But I would be *very* interested to see if there's a way to get anything
this low-level out of *any* modem...  (I'm still hoping I could use
something like that to ID the brand of modem at the remote end -- that
would be *great* for troubleshooting.)  So how did you get the INFO0 bits
directly?  Please share. :)

How new is your copy of the v.34 spec?  They charge money for copies of
that nowadays.  I have an older copy from before that time, but it's out
of date and doesn't include the 31.2K/33.6K extensions.

Mike Andrews (MA12) * [email-masked] * http://www.bit0.com/
VP, sysadmin, & network guy, Digital Crescent Inc, Frankfort KY
Internet services for Frankfort, Lawrenceburg, Owenton, Shelbyville
"Don't sweat the petty things, and don't pet the sweaty things."

-

---

From: Andrey Zimin <[email-masked]>
Date: Mon, 13 Mar 2000 02:04:38 +0000

> >From the ATS$ command:
== skip
> *direct* relationship between the S54 register and anything in the v.34
I know. Not all S-register on modem worked as defined in help and/or documentations.
For sample S55 - USR support only 64S-4D trellis on recive stream.

But I can`t understand why HiperDSP not support 2800 symbol rate, supported on
other USR modems line...

And other strange thing like that:
We are made wide statistical test calls for compiring Cisco (AS5300, MICA modem) and
USR Hiper NASes and get very strange output.
All calls on Hiper would have more power reduction on high frequencies, in comparison with MICA.
For sample two typical calls (from 200 calls series) at same time from one point and
one modem:
=======

 Connection Summary:  USR HiPer
+-----------------------+-----------------+-----------------------------+
| USRSTATS Version 4.19 | 03-08-00  20:12 | 9955554                     |
+-----------------------+-----------+-----+-----------------------------+
| Elapsed Time             00:00:31 | Modulation                  V.34+ |
| Blocks Received                 9 | Speed                 31200/24000 |
| Blers                           0 | Symbol Rate             3429/3429 |
| Blocks sent                    12 | Carrier Frequency       1959/1959 |
| Link Naks                       0 | Trellis Code        64S-4D/64S-4D |
| Blocks resent                   0 | Nonlinear Encoding          On/On |
| Link Timeouts                   0 | Precoding                   On/On |
| Chars sent                     12 | Shaping                     On/On |
| Octets sent                    12 | Preemphasis                   6/6 |
| Chars lost                      0 | Rx Lev/TX Lev/SNR      29/10/  38 |
| Chars Received                223 | Echo Loss    Near   65   Far   76 |
| Octets Received               227 | Roundtrip Delay                 6 |
| Protocol                     LAPM | Retrains Request/Grant        0/0 |
| Block Size                        | Fallback                 Disabled |
| Window Size                       | HST Line Reversals              0 |
| Compression                V42BIS | HST Equalization             Long |
| Dictionary Size              2048 | SV:                 DSP:          |
| String Length                  32 | Reason:                    Online |
+-----------------------------------+-----------------------------------+

 Channel Probe:
+---------------------------------------------------------------+
| -24 | . x X X X x x x . . . . . . . . . . . . . . . . . |   1 |
| -26 | . X X X X X X X X X x x . . . . . . . . . . . . . |   3 |
| -28 | . X X X X X X X X X X X X X x x . . . . . . . . . |   5 |
| -30 | . X X X X X X X X X X X X X X X X X x x . . . . . |   7 |
| -32 | X X X X X X X X X X X X X X X X X X X X X . . . . |   9 |
| -34 | X X X X X X X X X X X X X X X X X X X X X X . . . |  11 |
| -36 | X X X X X X X X X X X X X X X X X X X X X X X . . |  13 |
| -38 | X X X X X X X X X X X X X X X X X X X X X X X . . |  15 |
| -40 | X X X X X X X X X X X X X X X X X X X X X X X x . |  17 |
| -42 | X X X X X X X X X X X X X X X X X X X X X X X X . |  19 |
| -44 |=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=X=.=|  21 |
| -46 | X X X X X X X X X X X X X X X X X X X X X X X X . |  23 |
| -48 | X X X X X X X X X X X X X X X X X X X X X X X X X |  25 |
|Level+---------------------------------------------------+Atten|
|       0 0 0 0 0 0 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3       |
|       1 3 4 6 7 9 0 2 3 5 6 8 9 1 2 4 5 7 8 0 1 3 4 6 7       |
|       5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5       |
|       0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0       |
+---------------------------------------------------------------+

===============================================================================

 Connection Summary:   Cisco
+-----------------------+-----------------+-----------------------------+
| USRSTATS Version 4.19 | 03-08-00  20:28 | 9955555                     |
+-----------------------+-----------+-----+-----------------------------+
| Elapsed Time             00:00:33 | Modulation                  V.34+ |
| Blocks Received                10 | Speed                 31200/21600 |
| Blers                           0 | Symbol Rate             3429/3429 |
| Blocks sent                     9 | Carrier Frequency       1959/1959 |
| Link Naks                       0 | Trellis Code        64S-4D/64S-4D |
| Blocks resent                   0 | Nonlinear Encoding          On/On |
| Link Timeouts                   0 | Precoding                   On/On |
| Chars sent                     12 | Shaping                     On/On |
| Octets sent                     9 | Preemphasis                   6/6 |
| Chars lost                      0 | Rx Lev/TX Lev/SNR      31/10/  37 |
| Chars Received                255 | Echo Loss    Near   65   Far   76 |
| Octets Received               248 | Roundtrip Delay                 6 |
| Protocol                     LAPM | Retrains Request/Grant        0/0 |
| Block Size                        | Fallback                 Disabled |
| Window Size                       | HST Line Reversals              0 |
| Compression                V42BIS | HST Equalization             Long |
| Dictionary Size              2048 | SV:                 DSP:          |
| String Length                  32 | Reason:                    Online |
+-----------------------------------+-----------------------------------+

 Channel Probe:
+---------------------------------------------------------------+
| -26 | . . . x . . . . . . . . . . . . . . . . . . . . . |   0 |
| -28 | . x X X X X X x . . . . . . . . . . . . . . . . . |   2 |
| -30 | . X X X X X X X X X x x . . . . . . . . . . . . . |   4 |
| -32 | . X X X X X X X X X X X X X x x . . . . . . . . . |   6 |
| -34 | x X X X X X X X X X X X X X X X X X x x . . . . . |   8 |
| -36 | X X X X X X X X X X X X X X X X X X X X X X x . . |  10 |
| -38 | X X X X X X X X X X X X X X X X X X X X X X X x . |  12 |
| -40 | X X X X X X X X X X X X X X X X X X X X X X X X . |  14 |
| -42 | X X X X X X X X X X X X X X X X X X X X X X X X x |  16 |
|Level+---------------------------------------------------+Atten|
|       0 0 0 0 0 0 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3       |
|       1 3 4 6 7 9 0 2 3 5 6 8 9 1 2 4 5 7 8 0 1 3 4 6 7       |
|       5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5       |
|       0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0       |
+---------------------------------------------------------------+
========

> directly?  Please share. :)
Not I am. It maked for me one INPRO company engeneer who write code for
modem based on Lucent  (AT&T) 1634 datapump. He know many backdoors
for DSP. As I belive all modem on that chipset may give handshake sequince
for human who know secret word... ;-))

Other interesting thing - russian code for popular USR courer modem ID_SDL 4.03
is able get V90 and V42 sequence by ATI30I31 command.
ftp://ftp.usr.spb.ru/courier/id_sdl/
I am sorry, but documentation only on russian language...

Or special equipment for modem trobleshuting like http://www.analytic.ru/

> of date and doesn't include the 31.2K/33.6K extensions.
I have V0034e document. It cost no many - ~40$, like good book in shop.
=====
ITU-T V.34
TELECOMMUNICATION
STANDARDIZATION  SECTOR
OF  ITU (10/96)

SERIES V: DATA COMMUNICATION OVER THE TELEPHONE NETWORK
Interfaces and voiceband modems

A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased
point-to-point 2-wire telephone-type circuits

ITU-T  Recommendation  V.34
(Previously  CCITT  Recommendation)
======

Good luck !
======================
 Andrey Zimin | AVZ7-RIPE
           MTU-Intel ISP
        Moscow, Russia
======================

-

---

From: Mike Andrews <[email-masked]>
Date: Mon, 13 Mar 2000 04:58:53 +0000

> But I can`t understand why HiperDSP not support 2800 symbol rate, supported on

Dunno...  I can try it out here tomorrow.  I don't seem to have any calls
up at 2800 right now, though I did have some at 2743...

> For sample two typical calls (from 200 calls series) at same time from one point and

You can tweak the transmit power on the DSP's, though I'm not sure that's
what you're shooting for...

> for human who know secret word... ;-))

Ah, so you got it from the client side, not the server side.  I did dig
around and found documentation on Lucent's web site that says how to
pull the v.34 bits out of an LT Win Modem.  Not too secret after
all... :)

-

---

From: Andrey Zimin <[email-masked]>
Date: Mon, 13 Mar 2000 05:54:29 +0000

> > For sample two typical calls (from 200 calls series) at same time from one point and
Oh, sorry - not 200 calls series, only 20... ;-))

> what you're shooting for...
No, I wrote about losses in the top part of a range...

> Ah, so you got it from the client side, not the server side.  I did dig
Yes, sure...

> pull the v.34 bits out of an LT Win Modem.  Not too secret after
Aha, it`s so ineresting for all. Can you public URL? I`m not so fast for dig Lucent sites....

Good luck !
======================
 Andrey Zimin | AVZ7-RIPE
           MTU-Intel ISP
        Moscow, Russia
======================

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From: Jeff Mcadams <[email-masked]>
Date: Mon, 13 Mar 2000 18:38:39 +0000

Thus spake Mike Andrews
>So how did you get the INFO0 bits directly?  Please share. :)

mdmCsTrainingInfo perchance?

>that nowadays.  I have an older copy from before that time, but it's
>out of date and doesn't include the 31.2K/33.6K extensions.

I'd love to get a copy of the v.34 and v.90 specs for my reference here
too...anyone know how to get ahold of these?  Probably even willing to
pay if it isn't too terribly outrageous.
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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---

From: Mike Andrews <[email-masked]>
Date: Mon, 13 Mar 2000 22:51:47 +0000

> mdmCsTrainingInfo perchance?

That looks promising all of a sudden, yeah, except that it comes up as all
zeros on DSP's...  yet another feature mismatch.  It works on Quads
though, so I'll see if I can find a matchup.  (Anyone from 3Com who wants
to speak up here and save me the reverse engineering work...) :)

> pay if it isn't too terribly outrageous.

You can buy 'em from the ITU-T's website.  Problem is all the prices are
listed in Swiss Francs, and I don't know enough about the exchange rate to
know if it comes out to $20 or $2000. :)  Andrey Zimin hinted it was
closer to $20.  The specs *used* to be freely available, and I have a copy
of the 1994 v.34 spec, and v.42, v.42bis, v.8 and some others, but NOT
v.90.  Some of the people working on the linmodem.org project may have
copies too.

-

---

From: Sheldon Koehler <[email-masked]>
Date: Mon, 13 Mar 2000 23:01:07 +0000

I do not know how up to date these are, but this is free:
http://www.3com.com/technology/tech_net/white_papers/500659.html

Sheldon

----- Original Message -----
From: "Mike Andrews" <[email-masked]>
To: <[email-masked]>
Sent: Monday, March 13, 2000 12:47 PM
Subject: Re: (usr-tc) HiperDSP (2.051) can`t support 2800 sumbol rate?

-

---

From: Jeff Mcadams <[email-masked]>
Date: Tue, 14 Mar 2000 01:27:27 +0000

Thus spake Sheldon Koehler
>http://www.3com.com/technology/tech_net/white_papers/500659.html

Pretty much up-to-date, but not terribly in-depth.

Certainly not enough for my needs currently.  :)
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

-

---

From: Jeff Mcadams <[email-masked]>
Date: Tue, 14 Mar 2000 01:30:17 +0000

Thus spake Mike Andrews
>That looks promising all of a sudden, yeah, except that it comes up as
>all zeros on DSP's...  yet another feature mismatch.  It works on Quads
>though, so I'll see if I can find a matchup.  (Anyone from 3Com who
>wants to speak up here and save me the reverse engineering work...) :)

Indeed...Mike and I spoke by phone today...but it would be nice (hint,
hint, hint) for some kind 3Com person to hop in here and decode this
nice opaque string for us.  :)

>You can buy 'em from the ITU-T's website.  Problem is all the prices
>are listed in Swiss Francs, and I don't know enough about the exchange
>rate to know if it comes out to $20 or $2000. :)  Andrey Zimin hinted
>it was closer to $20.  The specs *used* to be freely available, and I
>have a copy of the 1994 v.34 spec, and v.42, v.42bis, v.8 and some
>others, but NOT v.90.  Some of the people working on the linmodem.org
>project may have copies too.

v.34 was, like, $22, and v.90 was around $13.
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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