[plug] PPP Problems and Timeouts

[Craig Ringer]

> its always had the problem (in linux only) of the tcp connections always
> timing out after about 10 seconds (widnows works fine)
Weird :-( I've had this only with bad line issues, and its normally
accompanied by drop-outs, etc.
 
> However i just noticed the following in the logs
> May 25 01:38:45 deltaflyer kernel: PPP: VJ decompression error
The data is compressed for transfer you <-> ISP. If a PPP frame is lost
and not retransmitted, this could happen. I'm guessing here. You could
ask pppd to not negotiate compression by setting the following options:
	nobsdcomp nodeflate novjccomp
and maybe even
	nocomp nopredictor1 

See if that helps or maybe just gives better log info. Also look at
"ifconfig ppp0" output and see if there are any errors listed. You can
also try pinging a remote host (pref. known to respond correctly to ICMP
echo requests [pings]) and see if you get any packet loss.

I'm kind of thrown by the way the problem doesn't happen under windows.
Try cat /proc/interrupts and see if your serial port is trying to share
an interrupt with anything, that could affect it.

> May 25 01:42:23 deltaflyer pppd[768]: sent [LCP EchoReq id=0x38
> magic=0xd1381ed8]
> May 25 01:42:23 deltaflyer pppd[768]: rcvd [LCP EchoRep id=0x38
> magic=0xfa1bc60]
These are normal and good. What is _not_ good is if you start seeing
them coming in with non-sequential ids (say 3 reqs then 3 replies, or 3
reqs then one reply, or 3 reqs and 3 replies in the wrong order). These
requests are kind of like a "ping" for PPP, just confirming that the
other side is still listening.

> also i tried the linux drivers for my internal modem (sm56 motorola) and
> i used rpm for debian to install them and it installs fine but when i
> modprobe the driver, it loads but is stuck 'initializing'
> sm56                 1345932   1  (initializing)
> anyone know why?
Support for internal winmodems (I assume its a winmodem by the fact you
had to get drivers) is largely broken except for a certain class of
Lucent winmodems. If you don't have one and the drivers don't work...
wait 3 months and try again then or sooner if you hear about big devel
breakthroughs or something.

Anyway its 4:30 in the morning, what the heck am I doing reading PLUG.

-- 
|  Craig Ringer
|  -- If it ain't broke, add features 'till it is