Modem 3G not connect

Hi,
I have a router Huawei HG556A Ver.A with a Huawei Modem K3765, which doesn't want to connect.
My APN is 'alai' without user&password neither pin

It seems to connect, and immediately it disconnects.

Can you help me? thanks.

My /etc/config/network file:

config interface 'wan'
        option proto '3g'
        option device '/dev/ttyUSB0'
        option service 'umts'
        option apn ‘alai'

logread console output:

Fri Apr 19 20:20:47 2024 daemon.notice pppd[13509]: pppd 2.4.9 started by root, uid 0

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: abort on (BUSY)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: abort on (NO CARRIER)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: abort on (ERROR)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: report (CONNECT)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: timeout set to 10 seconds

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: send (AT&F^M)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: expect (OK)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: AT&F^M^M

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: OK

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: -- got it

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: send (ATE1^M)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: expect (OK)

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: ^M

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: ATE1^M^M

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: OK

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: -- got it

Fri Apr 19 20:20:48 2024 local2.info chat[13510]: send (AT+CGDCONT=1,"IP","alai"^M)

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: timeout set to 30 seconds

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: expect (OK)

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: ^M

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: AT+CGDCONT=1,"IP","alai"^M^M

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: OK

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: -- got it

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: send (ATD*99***1#^M)

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: expect (CONNECT)

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: ^M

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: ATD*99***1#^M^M

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: CONNECT

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: -- got it

Fri Apr 19 20:20:49 2024 local2.info chat[13510]: send ( ^M)

Fri Apr 19 20:20:49 2024 daemon.debug pppd[13509]: Script USE_APN=alai DIALNUMBER=*99***1# /usr/sbin/chat -t5 -v -E -f /etc/chatscripts/3g.chat finished (pid 13510), status = 0x0

Fri Apr 19 20:20:49 2024 daemon.info pppd[13509]: Serial connection established.

Fri Apr 19 20:20:49 2024 daemon.debug pppd[13509]: using channel 205

Fri Apr 19 20:20:49 2024 kern.info kernel: [ 3047.444552] 3g-wan: renamed from ppp0

Fri Apr 19 20:20:49 2024 daemon.info pppd[13509]: Renamed interface ppp0 to 3g-wan

Fri Apr 19 20:20:49 2024 daemon.info pppd[13509]: Using interface 3g-wan

Fri Apr 19 20:20:49 2024 daemon.notice pppd[13509]: Connect: 3g-wan <--> /dev/ttyUSB0

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x9504388d>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: rcvd [LCP ConfReq id=0x39 <asyncmap 0x0> <auth chap MD5> <magic 0x1302554> <pcomp> <accomp>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: No auth is possible

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: sent [LCP ConfRej id=0x39 <auth chap MD5> <pcomp> <accomp>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x9504388d>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: rcvd [LCP ConfReq id=0x3a <asyncmap 0x0> <magic 0x1302554>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: sent [LCP ConfAck id=0x3a <asyncmap 0x0> <magic 0x1302554>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: sent [LCP EchoReq id=0x0 magic=0x9504388d]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: sent [IPV6CP ConfReq id=0x1 <addr fe80::e87a:2e30:0c08:8ec8>]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: rcvd [LCP DiscReq id=0x3b magic=0x1302554]

Fri Apr 19 20:20:50 2024 daemon.debug pppd[13509]: rcvd [LCP EchoRep id=0x0 magic=0x1302554 95 04 38 8d]

Fri Apr 19 20:20:51 2024 daemon.debug pppd[13509]: 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>]

Fri Apr 19 20:20:51 2024 daemon.debug pppd[13509]: 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>]

Fri Apr 19 20:20:52 2024 daemon.debug pppd[13509]: 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>]

Fri Apr 19 20:20:52 2024 daemon.debug pppd[13509]: 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>]

Fri Apr 19 20:20:53 2024 daemon.notice pppd[13509]: Modem hangup

Fri Apr 19 20:20:53 2024 daemon.notice pppd[13509]: Connection terminated.

Fri Apr 19 20:20:54 2024 daemon.info pppd[13509]: Exit.

Fri Apr 19 20:20:54 2024 daemon.notice netifd: Interface 'wan' is now down

Fri Apr 19 20:20:54 2024 daemon.notice netifd: Interface 'wan' is setting up now

In some cases you need to configure a username and password so that the authentication process does not stop. Any username and password will be accepted, but your modem has to send something.

2 Likes

From https://openwrt.org/docs/guide-user/network/wan/wwan/3gdongle :

If logread shows that the connection was established and CHAP authentication was successful, but the connection was immediately dropped after, then try:

option 'pppd_options' 'noipdefault'

2 Likes

I have tested with:

option username ‘’
option password ‘’

And

option username ‘xxx’
option password ‘xxx’

But they didn’t work.

I followed this guide to configure it, and I was testing this option, but it didn’t work

Anything new in the log after pppd_options is added?

Yes:

**Fri Apr 19 21:06:54 2024 daemon.info pppd[5570]: CHAP authentication succeeded**
**Fri Apr 19 21:06:54 2024 daemon.notice pppd[5570]: CHAP authentication succeeded**
Fri Apr 19 21:06:53 2024 daemon.info pppd[5570]: Serial connection established.
Fri Apr 19 21:06:53 2024 daemon.debug pppd[5570]: using channel 18
Fri Apr 19 21:06:53 2024 kern.info kernel: [  296.942168] 3g-wan: renamed from ppp0
Fri Apr 19 21:06:53 2024 daemon.info pppd[5570]: Renamed interface ppp0 to 3g-wan
Fri Apr 19 21:06:53 2024 daemon.info pppd[5570]: Using interface 3g-wan
Fri Apr 19 21:06:53 2024 daemon.notice pppd[5570]: Connect: 3g-wan <--> /dev/ttyUSB0
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xa15e2306>]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [LCP ConfReq id=0x8c <asyncmap 0x0> <auth chap MD5> <magic 0x10f6669> <pcomp> <accomp>]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: sent [LCP ConfRej id=0x8c <pcomp> <accomp>]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0xa15e2306>]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [LCP ConfReq id=0x8d <asyncmap 0x0> <auth chap MD5> <magic 0x10f6669>]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: sent [LCP ConfAck id=0x8d <asyncmap 0x0> <auth chap MD5> <magic 0x10f6669>]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: sent [LCP EchoReq id=0x0 magic=0xa15e2306]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [LCP DiscReq id=0x8e magic=0x10f6669]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [CHAP Challenge id=0x1 <36efe1de8a3420c31ab459772c543fa2>, name = "UMTS_CHAP_SRVR"]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: sent [CHAP Response id=0x1 <7aa7f455715a34c857d51bbafdf7d816>, name = "alai"]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [LCP EchoRep id=0x0 magic=0x10f6669 a1 5e 23 06]
Fri Apr 19 21:06:54 2024 daemon.debug pppd[5570]: rcvd [CHAP Success id=0x1 ""]
**Fri Apr 19 21:06:54 2024 daemon.info pppd[5570]: CHAP authentication succeeded**
**Fri Apr 19 21:06:54 2024 daemon.notice pppd[5570]: CHAP authentication succeeded**
Fri Apr 19 21:06:55 2024 daemon.debug pppd[5570]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
Fri Apr 19 21:06:55 2024 daemon.debug pppd[5570]: sent [IPV6CP ConfReq id=0x1 <addr fe80::08f7:b9b5:a172:7469>]
Fri Apr 19 21:06:55 2024 daemon.debug pppd[5570]: sent [LCP EchoReq id=0x1 magic=0xa15e2306]
Fri Apr 19 21:06:55 2024 daemon.debug pppd[5570]: rcvd [LCP EchoRep id=0x1 magic=0x10f6669 a1 5e 23 06]
Fri Apr 19 21:06:56 2024 daemon.debug pppd[5570]: 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>]
Fri Apr 19 21:06:56 2024 daemon.debug pppd[5570]: 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>]
Fri Apr 19 21:06:56 2024 daemon.notice pppd[5570]: Modem hangup
Fri Apr 19 21:06:56 2024 daemon.notice pppd[5570]: Connection terminated.