ttyUSB0 workarounds?

[jid...@jidanni.org]

Gentlemen, this works perfectly
# pppd /dev/ttyS0 user udn defaultroute noaccomp noauth nopersist \
usepeerdns 115200 connect 'chat -v -f /etc/chatscripts/generic -T 40508888'

Alas when I instead use /dev/ttyUSB0 I often get
"Couldn't get channel number: Input/output error".

What more pppd options might I try as a workaround?

I.e., how can I tighten up some options so my serial port adapter
succeeds just like a real serial port?

Yes I have ADSL, but I want to use my 56K modem as a backup.

[Moe Trin]

On Sun, 29 Jul 2012, in the Usenet newsgroup comp.protocols.ppp, in article
<jv2pv7$ovk$1...@news.datemas.de>, jid...@jidanni.org wrote:

>Gentlemen, this works perfectly

># pppd /dev/ttyS0 user udn defaultroute noaccomp noauth nopersist \
>usepeerdns 115200 connect 'chat -v -f /etc/chatscripts/generic -T
> 40508888'

OK - looks normal, but why the noaccomp noauth nopersist (shouldn't
be needed)?

>Alas when I instead use /dev/ttyUSB0 I often get
>"Couldn't get channel number: Input/output error".

1. /dev/ttyS0 is (as you know) an RS-232 serial port
2. /dev/ttyUSB0 doesn't exist on this system - hald problems? There
is a series of /dev/usb* but not wanted
3. ls -l /dev/ttyACM*
4. Once that's working, up the port speed from 115200 to 230400

>I.e., how can I tighten up some options so my serial port adapter
>succeeds just like a real serial port?

Is this an actual USB modem, or a USB-RS-232 adapter? In my case,
this is a US Robotics 5637 USB modem, and all I had to change was
the device call (from /dev/ttyS2 to /dev/ttyACM0). I up'ed the port
speed later. In the mean time, I'm using exactly the same basic
script that I've been using since... ppp-2.1.2d in late 1994.

>Yes I have ADSL, but I want to use my 56K modem as a backup.

When using the modem, down the default route to the ADSL link. The
pppd daemon will want the peer to authenticate to you if a default
exists, and the "stock" pppd will not replace a pre-existing default.
(SUSE among others added a "replacedefaultroute" option to bypass
the latter restriction - but it makes for much confusion).

Old guy

[jid...@jidanni.org]

OK now with a different adapter
0557:2008 ATEN International Co., Ltd UC-232A Serial Port [pl2303]
all works fine!

>>>>> "MT" == Moe Trin <ibupro...@painkiller.example.tld.invalid> writes:

MT> OK - looks normal, but why the noaccomp ...

OK, I removed noaccomp. Thanks.

[Moe Trin]

On Tue, 31 Jul 2012, in the Usenet newsgroup comp.protocols.ppp, in article
<jv79s1$jl2$1...@news.datemas.de>, jid...@jidanni.org wrote:

>OK now with a different adapter
>0557:2008 ATEN International Co., Ltd UC-232A Serial Port [pl2303]
>all works fine!

Thanks for the feedback, Dan. Are you implying the old adapter was
bad? Does 'lsusb' show the appropriate stuff?

[fermi ~]$ whatis lsusb
lsusb (8) - list USB devices
[fermi ~]$ lsusb | grep Robo
Bus 001 Device 012: ID 0baf:0303 U.S. Robotics
[fermi ~]$

Mentioned, my modem is a USB connected one. but the devices should
show up at the hardware level.

]>> # pppd /dev/ttyS0 user udn defaultroute noaccomp noauth nopersist \

>> OK - looks normal, but why the noaccomp ...

>OK, I removed noaccomp. Thanks.

noaccomp
Disable Address/Control compression in both directions
(send and receive).

noauth Do not require the peer to authenticate itself. This
option is privileged.

nopersist
Exit once a connection has been made and terminated.
This is the default unless the persist or demand option
has been specified.

Without the "no" options, pppd _should_ (yeah, I know) work OK. The
'noaccomp' should only be needed if connecting to a b0rken peer.
'noauth' is the default UNLESS there is a pre-existing default route
(and as mentioned, pppd then won't replace that default). The
'nopersist' shouldn't be needed either.

Old guy