Mobile broadband disconnections

[tpfkanep <tpfkanep gmail com>]

Hi,
I am experiening frequent disconnections when using NM. I used to have the same problems with [Xubuntu 8.10]. Then, the problem was solved by changing the default values of the following in [/etc/ppp/options] to:
lcp-echo-interval 0
lcp-echo-failure 0

I have since upgraded to [Xubuntu 9.04], with the latest version of NM, and I keep on getting disconnected, even after changing the values of [lcp-echo-interval] and [lcp-echo-failure] as in [Xubuntu 8.10].

Here are some extracts from some log files

debug:
-----
May 13 17:37:23 nicholas-desktop NetworkManager: <debug> [1242229043.781635] nm_serial_device_open(): (ttyACM0) opening device... 
May 13 17:37:24 nicholas-desktop NetworkManager: <debug> [1242229044.218431] nm_ppp_manager_start(): Command line: /usr/sbin/pppd nodetach lock nodefaultroute ttyACM0 noipdefault noauth usepeerdns lcp-echo-failure 0 lcp-echo-interval 0 ipparam /org/freedesktop/NetworkManager/PPP/0 plugin /usr/lib/pppd/2.4.4/nm-pppd-plugin.so 
May 13 17:37:24 nicholas-desktop NetworkManager: <debug> [1242229044.248610] nm_ppp_manager_start(): ppp started with pid 2641 
May 13 17:47:55 nicholas-desktop NetworkManager: <debug> [1242229675.627977] nm_serial_device_close(): Closing device 'ttyACM0' 
May 13 17:47:58 nicholas-desktop NetworkManager: <debug> [1242229678.000037] ensure_killed(): waiting for ppp pid 2641 to exit 
May 13 17:47:58 nicholas-desktop NetworkManager: <debug> [1242229678.000165] ensure_killed(): ppp pid 2641 cleaned up 
May 13 17:48:06 nicholas-desktop NetworkManager: <debug> [1242229686.828937] nm_serial_device_open(): (ttyACM0) opening device... 
May 13 17:48:07 nicholas-desktop NetworkManager: <debug> [1242229687.240962] nm_ppp_manager_start(): Command line: /usr/sbin/pppd nodetach lock nodefaultroute ttyACM0 noipdefault noauth usepeerdns lcp-echo-failure 0 lcp-echo-interval 0 ipparam /org/freedesktop/NetworkManager/PPP/1 plugin /usr/lib/pppd/2.4.4/nm-pppd-plugin.so 
May 13 17:48:07 nicholas-desktop NetworkManager: <debug> [1242229687.299174] nm_ppp_manager_start(): ppp started with pid 3027 
May 13 17:49:35 nicholas-desktop NetworkManager: <debug> [1242229775.427044] nm_serial_device_close(): Closing device 'ttyACM0' 
May 13 17:49:35 nicholas-desktop kernel: [  857.984676] mtrr: no MTRR for d0000000,10000000 found
May 13 17:49:37 nicholas-desktop NetworkManager: <debug> [1242229777.999887] ensure_killed(): waiting for ppp pid 3027 to exit 
May 13 17:49:37 nicholas-desktop NetworkManager: <debug> [1242229777.999997] ensure_killed(): ppp pid 3027 cleaned up 

messages:
--------
May 13 17:37:24 nicholas-desktop pppd[2641]: Plugin /usr/lib/pppd/2.4.4/nm-pppd-plugin.so loaded.
May 13 17:37:24 nicholas-desktop pppd[2641]: pppd 2.4.5 started by root, uid 0
May 13 17:37:24 nicholas-desktop pppd[2641]: Using interface ppp0
May 13 17:37:24 nicholas-desktop pppd[2641]: Connect: ppp0 <--> /dev/ttyACM0
May 13 17:37:24 nicholas-desktop pppd[2641]: Remote message: PAP access OK
May 13 17:37:24 nicholas-desktop pppd[2641]: PAP authentication succeeded
May 13 17:37:24 nicholas-desktop kernel: [  126.775852] PPP BSD Compression module registered
May 13 17:37:24 nicholas-desktop kernel: [  126.815335] PPP Deflate Compression module registered
May 13 17:37:25 nicholas-desktop pppd[2641]: local  IP address 172.28.90.247
May 13 17:37:25 nicholas-desktop pppd[2641]: remote IP address 172.28.90.0
May 13 17:37:25 nicholas-desktop pppd[2641]: primary   DNS address 41.208.11.219
May 13 17:37:25 nicholas-desktop pppd[2641]: secondary DNS address 209.212.96.1
May 13 17:37:34 nicholas-desktop kernel: [  137.111102] notification-da[2622]: segfault at 53ce80a ip 0a051371 sp bfdd7d7c error 4
May 13 17:47:55 nicholas-desktop pppd[2641]: LCP terminated by peer
May 13 17:47:55 nicholas-desktop pppd[2641]: Connect time 10.5 minutes.
May 13 17:47:55 nicholas-desktop pppd[2641]: Sent 236776 bytes, received 4496097 bytes.
May 13 17:47:55 nicholas-desktop pppd[2641]: Modem hangup
May 13 17:47:55 nicholas-desktop pppd[2641]: Connection terminated.
May 13 17:47:55 nicholas-desktop pppd[2641]: Exit.

daemon.log:
----------
May 13 17:37:23 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) starting connection 'MTN' 
May 13 17:37:23 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 3 -> 4 
May 13 17:37:23 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 1 of 5 (Device Prepare) scheduled... 
May 13 17:37:23 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 1 of 5 (Device Prepare) started... 
May 13 17:37:23 nicholas-desktop NetworkManager: <debug> [1242229043.781635] nm_serial_device_open(): (ttyACM0) opening device... 
May 13 17:37:23 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 1 of 5 (Device Prepare) complete. 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  (ttyACM0): powering up... 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Registered on Home network 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Associated with network: +COPS: 0,0,"MTN-SA" 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Connected, Woo! 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 2 of 5 (Device Configure) scheduled... 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 2 of 5 (Device Configure) starting... 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 4 -> 5 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Starting pppd connection 
May 13 17:37:24 nicholas-desktop NetworkManager: <debug> [1242229044.218431] nm_ppp_manager_start(): Command line: /usr/sbin/pppd nodetach lock nodefaultroute ttyACM0 noipdefault noauth usepeerdns lcp-echo-failure 0 lcp-echo-interval 0 ipparam /org/freedesktop/NetworkManager/PPP/0 plugin /usr/lib/pppd/2.4.4/nm-pppd-plugin.so 
May 13 17:37:24 nicholas-desktop NetworkManager: <debug> [1242229044.248610] nm_ppp_manager_start(): ppp started with pid 2641 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 2 of 5 (Device Configure) complete. 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 5 -> 6 
May 13 17:37:24 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 6 -> 7 
May 13 17:37:25 nicholas-desktop NetworkManager: <info>  PPP manager(IP Config Get) reply received. 
May 13 17:37:25 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 4 of 5 (IP Configure Get) scheduled... 
May 13 17:37:25 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 4 of 5 (IP Configure Get) started... 
May 13 17:37:25 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 5 of 5 (IP Configure Commit) scheduled... 
May 13 17:37:25 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 4 of 5 (IP Configure Get) complete. 
May 13 17:37:25 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 5 of 5 (IP Configure Commit) started... 
May 13 17:37:26 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 7 -> 8 
May 13 17:37:26 nicholas-desktop NetworkManager: <info>  Policy set 'MTN' (ppp0) as default for routing and DNS. 
May 13 17:37:26 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) successful, device activated. 
May 13 17:37:26 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) Stage 5 of 5 (IP Configure Commit) complete. 
May 13 17:37:30 nicholas-desktop ntpdate[2739]: no servers can be used, exiting
May 13 17:47:55 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 8 -> 7 
May 13 17:47:55 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 7 -> 9 
May 13 17:47:55 nicholas-desktop NetworkManager: <WARN>  monitor_cb(): Could not read ppp stats: No such device 
May 13 17:47:55 nicholas-desktop NetworkManager: <debug> [1242229675.627977] nm_serial_device_close(): Closing device 'ttyACM0' 
May 13 17:47:55 nicholas-desktop NetworkManager: <info>  Marking connection 'MTN' invalid. 
May 13 17:47:55 nicholas-desktop NetworkManager: <info>  Activation (ttyACM0) failed. 
May 13 17:47:55 nicholas-desktop NetworkManager: <info>  (ttyACM0): device state change: 9 -> 3 
May 13 17:47:55 nicholas-desktop NetworkManager: <info>  (ttyACM0): deactivating device (reason: 0). 
May 13 17:47:55 nicholas-desktop NetworkManager: nm_system_device_flush_ip4_routes_with_iface: assertion `iface_idx >= 0' failed
May 13 17:47:55 nicholas-desktop NetworkManager: nm_system_device_flush_ip4_addresses_with_iface: assertion `iface_idx >= 0' failed
May 13 17:47:58 nicholas-desktop NetworkManager: <debug> [1242229678.000037] ensure_killed(): waiting for ppp pid 2641 to exit 
May 13 17:47:58 nicholas-desktop NetworkManager: <debug> [1242229678.000165] ensure_killed(): ppp pid 2641 cleaned up 

Please help.