Subject: (usr-tc) [SUMMARY] slow MLPPP on HiPerARC

From: ROC Services <[email-masked]>
Date: Sat, 04 Dec 1999 19:46:22 +0000

After a little correspondence in private with a helpful and clueful 3Com
employee (thank you), we've figured out the cause of the slow MLPPP we
have been seeing with the HARC.

It seems that the HARC does not fragment packets for MLPPP, it simply
round-robins them out the interfaces.  While this doesn't cause
performance problems with sane protocols such as TCP, the software that
our customer is using attempts to reinvent TCP over UDP.  Badly.  It sends
one big packet, then waits for an ACK before sending the next one.

The net result of this is that on a simple "ping" style test, a multilink
bundle of any number of links won't show a significantly lower roundtrip
time than a single link would.

Also, I mentioned "mon ppp" showing traffic over only one interface on a
multilink connection.  This was confirmed as a "mon ppp" issue by 3Com.  
The "TAP USER" function shows traffic distributed across all interfaces.

The "mon ppp" problem is slated to be fixed in upcoming releases, and
there are plans to add a configurable parameter and/or RADIUS VSA to cause
the HARC to fragment outgoing packets on multilink.

As a temporary workaround until this code is available, we've found that
lowering the link MTU for this particular customer alleviates the problem.
It should be noted, however, that lowering MTUs may cause problems
accessing certain sites that block all incoming ICMP.

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From: [email-masked]
Date: Tue, 07 Dec 1999 20:10:30 +0000

Hello,

I Need to upgrade my Radius software (NT). Does anybody have any comments on
3Coms 6+ version verses any other venders versions. I also use radius to
authorize requests from Microsoft RRAS.

Thank You,
Jim Faulkner
GWE.NET

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From: Richard Lorbieski <[email-masked]>
Date: Tue, 07 Dec 1999 20:39:19 +0000

We use vircom radius. Works with SQL or livingston text files. Also
supports roaming and can limit duplicate logins. Package sells for
500-1000 (depends on options).

As for the USR radius, it's been over a year since I used it (version
5.x). It stored passwrods in MS Access format. It was a good starter
package. I'm sure they have made improvements since.

Vircom info:
http://www.vircom.com

-- 

Richard Lorbieski - [email-masked]
Chief Technical Officer - Senior System Administrator
Alpha1 Internet  http://www.alpha1.net
409.731.8236  - 877.4.alpha1 (877.425.7421)

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From: [email-masked]
Date: Tue, 07 Dec 1999 21:30:03 +0000

Richard,

When you upgraded from your USR 5 were you able to import your user data
from the access database or did you have to reenter all of the user/password
combos?

Jim

----- Original Message -----
From: Richard Lorbieski <[email-masked]>
To: <[email-masked]>
Sent: Tuesday, December 07, 1999 11:32 AM
Subject: Re: (usr-tc) Radius Recomendations

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From: Richard Lorbieski <[email-masked]>
Date: Tue, 07 Dec 1999 21:46:54 +0000

No, the passwords were encrypted. Yet I didn't spend much time trying to
unencrypted them. At the time, we had passwords written on the customer
signup sheet and put the passwords in manually.

Luckily, we had a small customer base. Today, I couldn't redo it
manually :-)...

Also, at that time we switched over from Quickbooks to a billing
software called Rodopi.

FYI, USR did have a util in their software that upgrade their database
from 4.x to 5.x . I would assume they have one for 6.x .

-- 

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From: Jeff Lynch <[email-masked]>
Date: Wed, 08 Dec 1999 16:35:55 +0000

> signup sheet and put the passwords in manually.

Thanks to this list (I forget who told us), but
we assimilated an acquired customer base from USR S&A on NT into
our Cistron RADIUS server on FreeBSD. Just export the S&A user database
to character delimited file. The "encrypted" passwords are very
easy to unencrypt as there is simply a constant offset added to each
character in the password (think ASCII value of each char). I don't know
if the same offset value is used everywhere, but we found it to be
the ASCII value for the CONTROL character (129? I don't have the
ASCII table in front of me).

--jeff

============================================================================ 
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email: [email-masked]		| 7 Area Codes in Chicagoland and NW Indiana
Voice: (219)322-2180		| 100Mbps+ Connectivity, 56K-DS3, V.90, ISDN
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