PPP ISDN Dual Channel Issues. [LONG]

Brian Somers brian at awfulhak.org
Wed May 23 12:42:57 BST 2001


Demon don't support multi-link unless you're using their test 
equipment.  I've asked for ``test status'' but haven't heard anything 
back.

Demon's current equipment negotiates multi-link, and may even handle 
it one in N times (replace N with the number of Demon ppp servers 
you might connect to), but the rest of the time, you end up talking 
to two different pieces of equipment that are stupid enough to 
announce themselves as being the same and then each try to establish 
an IP layer.  Chaos ensues.

FWIW, I currently have a Demon account, but I haven't tried 
multi-link in a few months.

> Hi,
> 
> Since Neil's had his fun I thought it was time for us to mail out some of
> our issues with userland ppp, I hope your not bored yet guys :-)
> 
> Right,  the problem is when using both channels on the isdn line it seems
> that the second will not stay up and be stable like the first channel.  If
> we only run one channel everything is fine but if we attempt to bring up
> both channels at the same time the second channel will not stay and keeps
> dropping and coming back up indefinetly.  Being no expert in ppp I decided
> to put an afternoon aside to read the man from top to bottom and came up
> with the following configuration, partly modified from the isdn example in
> /usr/share/examples/ppp/ppp.conf.isdn.  Our ISP is demon internet and as far
> as I can tell support multilink fine.
> 
> isdn:
>  set phone 08450798665  # Replace this with your ISPs phone number
> 
>  set authname bleh # Replace these with your login name & password.
>  set authkey bleh     # This profile assumes you're using PAP or CHAP.
> 
>  set enddisc mac        # Assuming you have a LAN
> 
>  enable lqr
>  set reconnect 3 5
>  set redial 3 10
>  set lqrperiod 45
>  disable pred1 deflate mppe
>  deny pred1 deflate mppe
> 
>  set timeout 60 300     # The minimum charge period is 5 minutes, so don't
>                         # hangup before then
> 
>  # We have no chat scripts in the ISDN world (yet)
>  set dial
>  set login
>  set logout
>  set hangup
> 
>  set device /dev/i4brbch0 /dev/i4brbch1         # Raw B-channel devices
>  set speed sync                                 # ISDN is synchronous
> 
>  # Take a wild guess at an IP number and let the other side decide
>  set ifaddr 172.16.0.1/0 212.0.0.0/0 0 0
>  add! default hisaddr
> 
>  set mrru 1500                          # Multilink mode please
> 
> #
>  clone 1,2
>  link deflink remove
>  link 1,2 set mode ddial
> 
> 
>  set mru 1504                           # Room for the MP header
> 
>  set server /tmp/ppp-isdn "" 0177       # The diagnostic port (-rw-------)
> 
> Ok, so theres the config.  The box is running 4.3-STABLE, uname -a gives the
> following
> 
> FreeBSD nas.claycrossbs.co.uk 4.3-STABLE FreeBSD 4.3-STABLE #10: Wed May  9
> 14:27:27 BST 2001     root at nas.claycrossbs.co.uk:/usr/obj/usr/src/sys/ISDN
> i386
> 
> And heres are some entries from syslog.
> 
> May 23 11:46:02 nas ppp[77]: Phase: 1: /dev/i4brbch0: CD detected
> May 23 11:46:02 nas ppp[77]: Phase: 1: carrier -> login
> May 23 11:46:02 nas ppp[77]: Phase: 1: login -> lcp
> May 23 11:46:02 nas ppp[77]: Phase: 2: /dev/i4brbch1: CD detected
> May 23 11:46:02 nas ppp[77]: Phase: 2: carrier -> login
> May 23 11:46:02 nas ppp[77]: Phase: 2: login -> lcp
> May 23 11:46:03 nas ppp[77]: Phase: bundle: Authenticate
> May 23 11:46:03 nas ppp[77]: Phase: 1: his = PAP, mine = none
> May 23 11:46:03 nas ppp[77]: Phase: Pap Output: claycross ********
> May 23 11:46:03 nas ppp[77]: Phase: 2: his = PAP, mine = none
> May 23 11:46:03 nas ppp[77]: Phase: Pap Output: claycross ********
> May 23 11:46:03 nas ppp[77]: Phase: Pap Input: SUCCESS ()
> May 23 11:46:03 nas ppp[77]: Phase: mp: Listening on
> /var/run/ppp--01-44454d4f4e31
> May 23 11:46:03 nas ppp[77]: Phase:     First link: 1
> May 23 11:46:03 nas ppp[77]: Phase: 1: lcp -> open
> May 23 11:46:03 nas ppp[77]: Phase: bundle: Network
> May 23 11:46:03 nas ppp[77]: Phase: Pap Input: SUCCESS ()
> May 23 11:46:03 nas ppp[77]: Phase: 2: lcp -> open
> 
> This isnt actually whats normally happening, usually both links connected
> and then the second one disconnects and re-connects again repeatedly.  I'll
> try and get the archived logs off the loghost later on today.
> 
> If anyone could also provide all the configs needed as well for connecting
> to demon via isdn I would be very gratefull.
> 
> Take it easy,
> 
> --
> Simon Griffiths
> Systems Administrator - Clay Cross Building Society
> Tel:+44(0)1246 862120 - Fax: +44(0)1246 250397

-- 
Brian <brian at Awfulhak.org>                        <brian@[uk.]FreeBSD.org>
      <http://www.Awfulhak.org>                   <brian@[uk.]OpenBSD.org>
Don't _EVER_ lose your sense of humour !






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