Failure to connect to internet with PPP

End-of-Life Product Cellular IoT Application Shield
1

pi@raspberrypi:~ $ sudo pon
pppd options in effect:
debug # (from /etc/ppp/peers/provider)
updetach # (from /etc/ppp/peers/provider)
dump # (from /etc/ppp/peers/provider)
noauth # (from /etc/ppp/peers/provider)
remotename 3gppp # (from /etc/ppp/peers/provider)
/dev/ttyUSB3 # (from /etc/ppp/peers/provider)
115200 # (from /etc/ppp/peers/provider)
lock # (from /etc/ppp/peers/provider)
connect chat -s -v -f /etc/chatscripts/chat-connect -T sp.telus.com # (from /etc/ppp/peers/provider)
disconnect chat -s -v -f /etc/chatscripts/chat-disconnect # (from /etc/ppp/peers/provider)
nocrtscts # (from /etc/ppp/peers/provider)
modem # (from /etc/ppp/peers/provider)
asyncmap 0 # (from /etc/ppp/options)
lcp-echo-failure 4 # (from /etc/ppp/options)
lcp-echo-interval 30 # (from /etc/ppp/options)
hide-password # (from /etc/ppp/peers/provider)
novj # (from /etc/ppp/peers/provider)
novjccomp # (from /etc/ppp/peers/provider)
ipcp-accept-local # (from /etc/ppp/peers/provider)
ipcp-accept-remote # (from /etc/ppp/peers/provider)
ipparam 3gppp # (from /etc/ppp/peers/provider)
noipdefault # (from /etc/ppp/peers/provider)
ipcp-max-failure 30 # (from /etc/ppp/peers/provider)
defaultroute # (from /etc/ppp/peers/provider)
usepeerdns # (from /etc/ppp/peers/provider)
noccp # (from /etc/ppp/peers/provider)
noipx # (from /etc/ppp/options)
abort on (BUSY)
abort on (NO CARRIER)
abort on (NO DIALTONE)
abort on (ERROR)
abort on (NO ANSWER)
timeout set to 30 seconds
send (AT^M)
expect (OK)
^M
OK
– got it

send (ATE0^M)
expect (OK)
^M
^M
OK
– got it

send (AT+QCFG=“band”,F,400A0E189F,A0E189F,1^M)
expect (OK)
^M
^M
OK
– got it

send (AT+QCFG=“nwscanseq”,01,1^M)
expect (OK)
^M
^M
OK
– got it

send (AT+QCFG=“nwscanmode”,1,1^M)
expect (OK)
^M
^M
OK
– got it

send (AT+QCFG=“iotopmode”,2,1^M)
expect (OK)
^M
^M
OK
– got it

send (ATI;+CSUB;+CSQ;+COPS?;+CGREG?;&D2^M)
expect (OK)
^M
^M
Quectel^M
BG96^M
Revision: BG96MAR02A10M1G^M
^M
SubEdition: V04^M
^M
+CSQ: 99,99^M
^M
+COPS: 0^M
^M
+CGREG: 0,2^M
^M
OK
– got it

send (AT+CGDCONT=1,“IP”,“sp.telus.com”,0,0^M)
expect (OK)
^M
^M
OK
– got it

send (ATD*99#^M)
expect (CONNECT)
^M
^M
CONNECT
– got it

Script chat -s -v -f /etc/chatscripts/chat-connect -T sp.telus.com finished (pid 1307), status = 0x0
Serial connection established.
using channel 3
Using interface ppp0
Connect: ppp0 <–> /dev/ttyUSB3
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xe2e3600> ]
rcvd [LCP ConfReq id=0x6 <asyncmap 0x0> <magic 0xd099f1d5> ]
No auth is possible
sent [LCP ConfRej id=0x6 ]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0xe2e3600> ]
rcvd [LCP ConfReq id=0x7 <asyncmap 0x0> <magic 0xd099f1d5> ]
sent [LCP ConfAck id=0x7 <asyncmap 0x0> <magic 0xd099f1d5> ]
sent [LCP EchoReq id=0x0 magic=0xe2e3600]
sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
rcvd [LCP DiscReq id=0x8 magic=0xd099f1d5]
rcvd [LCP EchoRep id=0x0 magic=0xd099f1d5 0e 2e 36 00]
rcvd [IPCP ConfNak id=0x1 <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
sent [IPCP ConfReq id=0x2 <addr 0.0.0.0> <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
rcvd [IPCP ConfNak id=0x2 <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
sent [IPCP ConfReq id=0x3 <addr 0.0.0.0> <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]

…
rcvd [IPCP ConfNak id=0x24 <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
sent [IPCP ConfReq id=0x25 <addr 0.0.0.0> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
Modem hangup
Connection terminated.

2

Hi,

Make sure your antenna is connected properly.
+CSQ: 0,99^M indicates you have very weak signal strength.

3

IMG_20200618_134048
IMG_20200618_134048666×888 102 KB

I believe I have it connected correctly

When I was testing it out obviously the usb was connected

4

connections are correct, assuming they are “seated” properly.
are you above ground? ‘99’ = Invalid signal. It was enough to successfully handshake but when not to get an ip assignment.
assuming correct & activated SIM.
how’s your input power? Any under-voltage messages in the dmesg log?
what else is drawing power out of your USB2 & 3 buses?
can you run headless, no peripherals connected for troubleshooting?
get your project outdoors or as close as possible.
Post back, let everyone know your findings.
Thanks

5

What do you mean by “seated” properly?
I moved my setup outdoors and when I tried the sudo pon command I got the flicker quickly state indicating that data transfer began to happen but once again the same thing happened the modem got hang up and connection was terminated. I tried again without any peripherals just a remote connection to a laptop and same response.

Finally I was able to get an connection to PPP and it gave me a ip address and everything but didn’t last for long and I wasn’t able to open anything on the browser. I am assuming something must be wrong with my antenna?

6

Hi there,
“seated”, simply another term for connected properly with good connection.
You have the BG96 from Quectel, that’s CAT-M1 / NB-IoT.
Top speed is going to be < 400k and both are designed for m2m (very small packets) e.g., MQTT.

I don’t know that you can “load” a browser and send/receive http?

What was your signal strength when you established a carrier session & received an ip?
perhaps try a simple ping command out to google (8.8.8.8 / .4.4). set a wait time of say 60 seconds and see if the connection holds.

I’m not sure what your requirements are for the LTE hat you purchased. If I’m wrong, I apologize and would appreciate your posting of a description of your project.

Thanks,
Mark

1 Like
7

I just want to chime in here because I had a similar issue and was able to fix it.

My setup is RASPBERRY PI CELLULAR IOT HAT (Quectel BG96) with AT&T LTE-M One Rate Plan (64kbps unlimited) in the united states.

My troubleshooting steps:

  • Use Pi 3b+ out of the box power supply.
  • Open door to outside.
  • Squeeze down the coax connectors to the HAT (same Pulse FPC antenna as OP).

Finally I was able to get it to work. Running a command line speed test via speedtest-cli, i am getting:
Download: .05 Mbit/sec
Upload: .07 Mbit/sec

These low speeds are somewhat expected from the cheap low speed data plan.

FWIW, the issue seemed sensitive to the door being open. I get the impression its a pretty weak connection. But I’m having a problem reproducing any single step of the troubleshooting behavior. Also keep in mind these board level micro coax connectors are extremely fragile and not meant for repetitive insertion/extraction, and damage to the connector may not be visible to the naked eye.

8

Actually, I’m finding my connection to be wildly unstable, with hangup and successful connections varying by the minute. I could have a decent connection, then 5 minutes later restart my machine and experience the hangup issue again without touching any hardware or moving anything. I’ve tried several places in my house with a similar problem. Either the NB-IoT has a really crappy signal at my house or the network/hardware is flaky.

I’ve had rock solid connections with the EC25A and a regular Cat 4 4G T-mobile signal.

9

NB-IoT / CAT-1 has a very high latency. Folks like to test it by pinging IP’s and trying to browse a website. You are going to get some not-so-pleasant results and that is to be expected.

Here is a good test if you are using a Raspberry Pi. Setup MyDevice’s Cayene on your RPi. Use the App on your cell phone or from a web browser to control your Pi. You can reboot it, toggle I/O pins etc. Setup an LED to toggle it on and off. It is very easy and intuitive to setup. Go to https://developers.mydevices.com/cayenne/features/ It is Free!

10

@Steve I have had the exact same experience and that is par for the course with Cat-1 or NB-IoT. As we have found out… things run much better on CAT 4+ LTE,

1 Like