Q2698 PPP disconnect (with CREG:0)

Dear,

I’m facing an PPP issue with Q2698 module.
PPP connection is lost very often while no data are transmitting since a long period (sometimes it can happens after few secondes), usually few minutes.

here are steps :

  • power up Q2698
  • establish ppp connexion
  • wait some seconds or minutes
  • run command : ping 8.8.8.8 (I’m using Ping command, but issue occurs with any other network sollication (traceroute, TCP…).

Then three cases occur :
1) ping is working, then cancel ping and wait again
2) ping doesn’t reach host, PPP connexion is lost and a try to reconnect and succeed
2) ping doesn’t reach host, PPP connexion is lost and a try to reconnect and never succeed because Q2698 UART is no longer responding (hardware reset will fix it)

At the moment I run Ping command, Q2698 seems to loose GSM link because at the same moment a +CREG:0 is send.
This is very surprising to receive +CREG:0 as soons as a network sollication occurs, because LCP echo requests were acknowledged a long period just before!

Context :

  • Modem Q2698
  • Firmware modem : R7.53.0.201502160745.Q2698 1825268 021615 07:45
  • SIM card orange, apn orange.m2m.spec
  • UART baudrate at 460800 bauds
  • i.MX27 with OS Linux 4.1
  • pppd version 2.4.7

Logs (system)

Nov  4 05:49:24 chat[14826]: send (AT^M)
Nov  4 05:49:24 chat[14826]: expect (OK)
Nov  4 05:49:24 chat[14826]: AT^M^M
Nov  4 05:49:24 chat[14826]: OK
Nov  4 05:49:24 chat[14826]:  -- got it
Nov  4 05:49:24 chat[14826]: send (AT+CGDCONT=1,"IP","orange.m2m.spec"^M)
Nov  4 05:49:25 chat[14826]: expect (OK)
Nov  4 05:49:25 chat[14826]: ^M
Nov  4 05:49:25 chat[14826]: AT+CGDCONT=1,"IP","orange.m2m.spec"^M^M
Nov  4 05:49:25 chat[14826]: OK
Nov  4 05:49:25 chat[14826]:  -- got it
Nov  4 05:49:25 chat[14826]: send (ATDT*99***1#^M)
Nov  4 05:49:25 chat[14826]: expect (CONNECT)
Nov  4 05:49:25 chat[14826]: ^M
Nov  4 05:49:25 chat[14826]: ATDT*99***1#^M^M
Nov  4 05:49:25 chat[14826]: CONNECT
Nov  4 05:49:25 chat[14826]:  -- got it
Nov  4 05:49:25 chat[14826]: send (\d)
Nov  4 05:49:26 pppd[6634]: Serial connection established.
Nov  4 05:49:26 pppd[6634]: Using interface ppp0
Nov  4 05:49:26 pppd[6634]: Connect: ppp0 <--> /dev/ttymxc2

[ LCP echo requests are well transmit/received : checked by spying UART link between processor and Q2698]
[ Here i'm doing a ping command : ping 8.8.8.8]
[ Ping doesn't reach host ]
[ LCP echo requests are no longer acknowledged ]


Nov  4 05:49:48 pppd[6634]: No response to 10 echo-requests
Nov  4 05:49:48 pppd[6634]: Serial link appears to be disconnected.
Nov  4 05:49:54 pppd[6634]: Connection terminated.
Nov  4 05:49:54 chat[14862]: abort on (BUSY)
Nov  4 05:49:54 chat[14862]: abort on (ERROR)
Nov  4 05:49:54 chat[14862]: abort on (NO DIALTONE)
Nov  4 05:49:54 chat[14862]: send (\K^M)
Nov  4 05:49:54 chat[14862]: send (~+++^M)
Nov  4 05:49:55 pppd[6634]: Serial link disconnected.
Nov  4 05:49:56 pppd[6634]: Modem hangup

[ pppd try to restart connexion, sometimes it fail because modem's UART is not responding (uart on its USB port is working, so Q2698 is not freezed) ]

Same log by pppd

start Fri Nov  4 14:31:52 2016
time  1.1s
sent   41                                               A
sent   54                                               T
time  0.1s
sent   0d                                               .
rcvd   0d 0a 4f 4b 0d 0a                                ..OK..
time  8.9s
sent   41                                               A
sent   54                                               T
sent   2b                                               +
sent   43                                               C
sent   47                                               G
sent   44                                               D
sent   43                                               C
sent   4f                                               O
sent   4e                                               N
time  0.1s
sent   54                                               T
sent   3d                                               =
sent   31                                               1
sent   2c                                               ,
sent   22                                               "
sent   49                                               I
sent   50                                               P
sent   22                                               "
sent   2c                                               ,
sent   22                                               "
time  0.1s
sent   6f                                               o
sent   72                                               r
sent   61                                               a
sent   6e                                               n
sent   67                                               g
sent   65                                               e
sent   2e                                               .
sent   6d                                               m
sent   32                                               2
time  0.1s
sent   6d                                               m
sent   2e                                               .
sent   73                                               s
sent   70                                               p
sent   65                                               e
sent   63                                               c
sent   22                                               "
sent   0d                                               .
time  0.2s
rcvd   0d 0a 4f 4b 0d 0a                                ..OK..
sent   41                                               A
sent   54                                               T
sent   44                                               D
sent   54                                               T
time  0.1s
sent   2a                                               *
sent   39                                               9
sent   39                                               9
sent   2a                                               *
sent   2a                                               *
sent   2a                                               *
sent   31                                               1
sent   23                                               #
sent   0d                                               .
time  0.1s
rcvd   0d 0a 43 4f 4e 4e 45 43 54 20 34 36 30 38 30 30  ..CONNECT 460800
       0d 0a 7e ff 7d 23 c0 21 7d 21 7d 21 7d 20 7d 36  ..~.}#.!}!}!} }6
       7d 21 7d 24 7d 25 dc 7d 25 7d 26 7d 3c 7d 26 da  }!}$}%.}%}&}<}&.
       c8 7d 27 7d 22 7d 28 7d 22 7d 23 7d 24 c0 23 52  .}'}"}(}"}#}$.#R
       66 7e                                            f~
time  2.1s
sent   7e ff 7d 23 c0 21 7d 21 7d 21 7d 20 7d 34 7d 22  ~.}#.!}!}!} }4}"
       7d 26 7d 20 7d 20 7d 20 7d 20 7d 25 7d 26 98 9f  }&} } } } }%}&..
       c7 c9 7d 27 7d 22 7d 28 7d 22 98 87 7e           ..}'}"}(}"..~
rcvd   7e ff 7d 23 c0 21 7d 22 7d 21                    ~.}#.!}"}!
rcvd   7d 20 7d 34 7d 22 7d 26 7d 20 7d 20 7d 20 7d 20  } }4}"}&} } } } 
       7d 25 7d 26 98 9f c7 c9 7d 27 7d 22 7d 28 7d 22  }%}&....}'}"}(}"
       73 ee 7e                                         s.~
time  0.9s
rcvd   7e ff 7d 23 c0 21 7d 21 7d 21 7d 20 7d           ~.}#.!}!}!} }
rcvd   36 7d 21 7d 24 7d 25 dc 7d 25 7d 26 7d 3c 7d 26  6}!}$}%.}%}&}<}&
       da c8 7d 27 7d 22 7d 28 7d 22 7d 23 7d 24 c0 23  ..}'}"}(}"}#}$.#
       52 66 7e                                         Rf~
sent   7e ff 7d 23 c0 21 7d 22 7d 21 7d 20 7d 36 7d 21  ~.}#.!}"}!} }6}!
       7d 24 7d 25 dc 7d 25 7d 26 7d 3c 7d 26 da c8 7d  }$}%.}%}&}<}&..}
       27 7d 22 7d 28 7d 22 7d 23 7d 24 c0 23 a4 95 7e  '}"}(}"}#}$.#..~
       c0 21 7d 29 7d 20 7d 20 7d 28 98 9f c7 c9 d4 c8  .!})} } }(......
       7e c0 23 7d 21 7d 21 7d 20 7d 2a 7d 23 74 68 37  ~.#}!}!} }*}#th7
       7d 21 2a 43 d8 7e                                }!*C.~
time  2.0s
sent   7e c0 21 7d 29 7d 21 7d 20 7d 28 98 9f c7 c9 7d  ~.!})}!} }(....}
       21 57 7e                                         !W~
time  1.0s
sent   7e c0 23 7d 21 7d 22 7d 20 7d 2a 7d 23 74 68 37  ~.#}!}"} }*}#th7
       7d 21 2a 44 7d 2e 7e                             }!*D}.~
time  1.0s
sent   7e c0 21 7d 29 7d 22 7d 20 7d 28 98 9f c7 c9 6f  ~.!})}"} }(....o
       ff 7e                                            .~
time  2.0s
sent   7e c0 23 7d 21 7d 23 7d 20 7d 2a 7d 23 74 68 37  ~.#}!}#} }*}#th7
       7d 21 2a b9 43 7e c0 21 7d 29 7d 23 7d 20 7d 28  }!*.C~.!})}#} }(
       98 9f c7 c9 ba 60 7e                             .....`~
time  2.0s
sent   7e c0 21 7d 29 7d 24 7d 20 7d 28 98 9f c7 c9 a2  ~.!})}$} }(.....
       a7 7e                                            .~
time  1.0s
sent   7e c0 23 7d 21 7d 24 7d 20 7d 2a 7d 23 74 68 37  ~.#}!}$} }*}#th7
       7d 21 2a 5b aa 7e                                }!*[.~
time  1.0s
sent   7e c0 21 7d 29 7d 25 7d 20 7d 28 98 9f c7 c9 77  ~.!})}%} }(....w
       38 7e                                            8~
time  2.0s
sent   7e c0 23 7d 21 7d 25 7d 20 7d 2a 7d 23 74 68 37  ~.#}!}%} }*}#th7
       7d 21 2a a6 e7 7e                                }!*..~
sent   c0 21 7d 29 7d 26 7d 20 7d 28 98 9f c7 c9 7d 39  .!})}&} }(....}9
       90 7e                                            .~
time  2.1s
sent   7e c0 21 7d 29 7d 27 7d 20 7d 28 98 9f c7 c9 cc  ~.!})}'} }(.....
       7d 2f 7e                                         }/~
time  0.9s
sent   c0 23 7d 21 7d 26 7d 20 7d 2a 7d 23 74 68 37 7d  .#}!}&} }*}#th7}
       21 2a a1 31 7e                                   !*.1~
time  0.6s

[ Here i'm doing a ping command : ping 8.8.8.8]

rcvd   0d 0a 2b 43 52 45 47 3a 20 30 0d 0a              ..+CREG: 0..
rcvd   0d 0a 2b 43 47 52 45 47 3a 20 30 0d 0a           ..+CGREG: 0..
time  0.5s
sent   7e c0 21 7d 29 7d 28 7d 20 7d 28 98 9f c7 c9 38  ~.!})}(} }(....8
       7d 36 7e                                         }6~
time  2.0s
sent   7e c0 23 7d 21 7d 27 7d 20 7d 2a 7d 23 74 68 37  ~.#}!}'} }*}#th7
       7d 21 2a 5c 7c 7e                                }!*\|~
sent   c0 21 7d 29 7d 29 7d 20 7d 28 98 9f c7 c9 ed 89  .!})})} }(......
       7e                                               ~
time  2.0s
sent   7e ff 7d 23 c0 21 7d 25 7d 22 7d 20 7d 37 50 65  ~.}#.!}%}"} }7Pe
       65 72 20 6e 6f 74 20 72 65 73 70 6f 6e 64 69 6e  er not respondin
       67 2e 50 7e                                      g.P~
time  0.5s
rcvd   0d 0a 2b 43 52 45 47 3a 20 32 0d 0a              ..+CREG: 2..
time  1.8s
rcvd   0d 0a 2b 43 52 45 47 3a 20 31 0d 0a              ..+CREG: 1..
time  0.7s
sent   7e ff 7d 23 c0 21 7d 25 7d 23 7d 20 7d 37 50 65  ~.}#.!}%}#} }7Pe
       65 72 20 6e 6f 74 20 72 65 73 70 6f 6e 64 69 6e  er not respondin
       67 73 f9 7e                                      gs.~
time  0.4s
rcvd   0d 0a 2b 43 47 52 45 47 3a 20 31 0d 0a           ..+CGREG: 1..
time  2.7s
sent   0d                                               .
sent   7e                                               ~
sent   2b                                               +
sent   2b                                               +
sent   2b                                               +

Does anyone exprienced the same issue?

I have checke lastest firmware release :
http://source.sierrawireless.com/resources/airprime/software/release_notes/firmware_7_53/

I don’t have same date code than in the docmentation :
My q2698 firmware : 201404011204 , in the release not : 201502160745
Same difference with Internet library package and Extended AT application.

Does the firmware package available on the sierra website is really the latest ?

ATI9
"DWL"," SWI6200T_02.02.04.22BT R3887 CNSHZ-ED-XP0031 2015/02/13 19:09:00","","Si
erra Wireless",0,"","00000000","00000000"
"FW","FW_753_24.Q268Fx","R7.53.0.201502160745.Q2698","Sierra Wireless",1825268,"
021615 07:45","99ed13d2","10002020"
"MODEM 3G+","Revision: SWI6200T_02.02.04.22AP R3887 CNSHZ-ED-XP0031 2015/02/13 1
9:23:44"
"OAT","v1.3.2.20140403125739","Extended AT Application","Sierra Wireless",710648
,"040314 12:58","7a8a2ae4","10700000"
 -"Developer Studio","2.3.2.201310241753"
 -"Open AT OS Package","6.53.0.201403070947"
 -"Firmware Package","7.53.0.201404011204"
 -"Internet Library Package","5.57.0.201404020912"
 -"Location Library Package","1.4.7.201401140843"
 -"Security Library Package","2.2.0.201306261000"
 -"eCall Library Package","1.2.3.201306191228"
 -"Jamming Library Package","1.1.0.201311050825"
 -"ExtendedATApplication Library Package","1.3.2.201404031257"
"ROM","8400000"
"RAM","4000000"
"OATRAM","800000"
"DWLNAME","Q2698"

I have try same steps with a an HL8548 + carrier board on my device, and I don’t have the same issue, so I think the problem is on Q2698 side.

In a nutsheel, i’m wondering if I have the latest firmware revision and, If sierra wireless had really fix bug with ID 69969 ?

Regards,
Julien C.

Hello,

here are some Sierra internal logs before and after a modem reboot (while PPP is active) :

before PPP connexion :

AT+WLERR=1                                                                  ¦
+WLERR: 0,1,"IRQ disabled for a too long time"
+WLERR: 0,2,"IRQ disabled for a too long time"
+WLERR: 0,3,"Except RTX: task ADL, heap memory corruption of 0x414081E8, caller= 0x100386e3"
+WLERR: 0,4,"IRQ disabled for a too long time"
+WLERR: 1,0
+WLERR: 2,33286144,33554432,28

[[ launching ppp connexion, then modem freeze an reboot ]]

AT+WLERR=1                                                                  ¦
+WLERR: 0,1,"IRQ disabled for a too long time"
+WLERR: 0,2,"Except RTX: task ADL, heap memory corruption of 0x414081E8, caller
= 0x100386e3"
+WLERR: 0,3,"IRQ disabled for a too long time"
+WLERR: 0,4,"Except RTX: task ADL, heap memory corruption of 0x3FF0, caller = 0x100386e3"
+WLERR: 1,6
+WLERR: 2,33284096,33554432,29

This new line has appeared :
+WLERR: 0,4,“Except RTX: task ADL, heap memory corruption of 0x3FF0, caller = 0x100386e3”

Who know what it means ?

Regards,
Julien