Re: 0.93R6: pppd gives "block on freelist isn't free" system errors

[Jeffrey Ebert <jebert@ix.netcom.com>]

Nathan O. Siemers wrote:
>
> before you post this thread to usenet, try
> -vj
> in the ppp options file ( I think this is correct, the flag has
> changed in some versions).  This disables header compression,
> Xyplex-ppp interactions sometimes need this to work.
>

Thanks Nathan,

I tried this after finding the same advice in a dejanews search (thanks
Dan). It appears to work, but the line hangs up frequently. Not a huge
problem, since I am running diald, but an inconvenience. Because I have
only tried it once or twice, I cannot yet rule out line noise. I will
reduce mru and mtu as an experiment, after I have tested the current
config more.

I think that the interesting issue here is the error message that is
reported by the kernel. If you look at the kernel source, it is a _very_
unlikely error message. I'll write this up as bug (if it hasn't been)
for the debian packages and it will be forwarded to upstream
maintainers, right? If nothing else, the info can be added to the docs.

More info may be found in the PPP-HOWTO:

 7.8.  protocol reject for protocol fffb

  This usually occurs when you are trying to connect to a Xyplex
  terminal server. Version 5.1 of the Xyplex terminal server software,
  according to Xyplex, has numerous problems with PPP. It is strongly
  recommended that you update the Xyplex software to at least version
  5.3.

  If you must use version 5.1, then use the pppd option "vj-max-slots 3"
  to limit the number of slots to three. The problem on the Xyplex
  server is that it will accept the request for the default 16 slots,
  but fail to operate beyond the third slot. It should have return a NAK
  frame with the limit, but it does not.

  Alternately, you can disable the Van Jacobson header compression with
  the option "-vj".

So, I'm going to check with the Xyplex sysadmin at work to see if an
upgrade is a possibility.

> I've never found a complete solution to the Xyplex problem, this is
> the best I've got.  Let me know how things go. (My transfer is also
> much better on other ppp servers)

Do you mean that the performance isn't as good? That was my experience
today as well. I believe that VJ header compression improves performance
quite a bit, but I didn't think it had as big an impact as I am seeing.
I'll have to play with it more before I am sure.

-- 
Jeffrey Ebert-------------------------------------jebert@ix.netcom.com
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