Share your knowledge at the LQ Wiki.
Go Back > Forums > Linux Forums > Linux - Networking
User Name
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.


  Search this Thread
Old 10-23-2004, 08:08 PM   #1
Registered: Jul 2002
Location: Florida
Distribution: Centos, Slackware
Posts: 260

Rep: Reputation: 30
pppd and Airlink Pinpoint CDMA modem woes

Can anyone help me with a problem I am having?

I have a linux-based device connected via serial port to a pinpoint CDMA modem.

I have had this working (about 3 months ago), but now when I try to establish
a ppp connection, I get errors (see below).

Here are the relevant files:

bash-2.05# cat /etc/ppp/peers/airlink
mtu 1024
mru 1024
lcp-echo-failure 0
lcp-echo-interval 0
connect '/usr/sbin/chat -s -v -f /etc/ppp/chat-airlink'

bash-2.05# cat /etc/ppp/chat-airlink
"" "AT"
OK "AT&D0"
OK "ATD#19788"

And here is my command to establish the connection:

bash-2.05# pppd call airlink

And here is the log output:

bash-2.05# tail /var/log/messages


Oct 24 00:24:14 hummer pppd[682]: pppd 2.4.1 started by root, uid 0
Oct 24 00:24:15 hummer chat[683]: send (AT^M)
Oct 24 00:24:15 hummer chat[683]: expect (OK)
Oct 24 00:24:19 hummer chat[1105]: ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@
Oct 24 00:24:55 hummer last message repeated 5 times
Oct 24 00:24:55 hummer chat[1105]: ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@
Oct 24 00:25:00 hummer chat[1105]: alarm
Oct 24 00:25:00 hummer chat[1105]: Failed

The really odd thing is, if I connect to the pinpoint modem using minicom
via /dev/ttyS0 at 115200 baud and issue the AT commands manually, I get
the expected replies,

The differences (of which I am aware) are that I have an ipsec tunnel over
a wireless ethernet link, the GPS output to an IP feature of the pinpoint
modem was enabled, and I'm using a different SBC. We are updating the
firmware on the modem, but is there anything you see here that I am doing
wrong? No I haven't tried connecting to a regular telephone modem via
the serial port, I don't have any of those handy at the moment.

Thanks for any help.

Old 11-09-2004, 11:39 AM   #2
Registered: Jul 2002
Location: Florida
Distribution: Centos, Slackware
Posts: 260

Original Poster
Rep: Reputation: 30
Well ... not too many folks using this device, I guess.

It turns out I was doing everything right, but it just won't
work while the ipsec is running.
After bringing down the ipsec connection, I was again able to
bring up the ppp connection to the modem.
I don't know why there is a conflict there, but there is.

Maybe this extra bit of info will be useful. Maybe someone
reading this will know what the conflict is and tell me how
to work around it -- besides shutting off my ipsec.

Just thought the 40-someodd of you who were curious enough
to read the thread might be interested.



Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
pppd error using cdma modem itecliu Linux - Wireless Networking 2 11-18-2009 05:52 AM
CDMA Modem via USB not working in SuSE 10 akabatman2 SUSE / openSUSE 3 11-09-2005 10:02 PM
CDMA Stand Alone Modem For Linux xyzxyz Linux - Wireless Networking 1 03-07-2005 01:19 AM
How To Setup CDMA modem with Serial Connection stpopoola Linux - Hardware 1 02-25-2005 03:34 AM
USB to serial convertor + CDMA modem priya_siddharth Linux - Hardware 1 04-11-2004 07:34 AM > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 10:26 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration