topic Will try and let you know my in Wireless

3G cellular interface not working

mohdtaamneh — Mon, 05 Jul 2021 11:44:01 GMT

Dears,

I need your help in find the root cause for the following behavior.

I am trying to configure a cellular interface on cisco C881G-4G-GA-K9 router as 3G. But the interface not operational. its showing up/up (spoofing) and not getting IP address from SP as suppose to do.

Router#sho int cellular 0
Cellular0 is up (spoofing), line protocol is up (spoofing)
Hardware is 4G WWAN Modem - Global (Europe & Australia) Multimode LTE/DC-HSPA+/HSPA+/HSPA/U
Internet address will be assigned dynamically by the network
MTU 1500 bytes, BW 9 Kbit/sec, DLY 100000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation SLIP, loopback not set
Keepalive not supported

Configuration on the port as follow:

interface Cellular0
ip address negotiated
ip nat outside
ip virtual-reassembly in
encapsulation slip
dialer in-band
dialer idle-timeout 0
dialer string gsm
dialer string GSM
dialer-group 1
async mode interactive

controller Cellular 0
lte modem link-recovery rssi onset-threshold -110
lte modem link-recovery monitor-timer 20
lte modem link-recovery wait-timer 10
lte modem link-recovery debounce-count 6
!

I tried the same 3G sim card on cisco C881G+7-k9 router and its work fine and link come up. Also, the cellular interface getting IP address and I can reach outside.

Any special configuration need to be added on the controller/ cellular interface?

Attached is a debug output collected from the router.

Best Regards,

Mohammad Taamneh

You haven't shown enough

Philip D'Ath — Mon, 07 Mar 2016 20:41:13 GMT

You haven't shown enough config. Basically you need to ...

Configre an APN.

cellular 0 lte profile create 1 <apn>

Use a dialer string like this. You currently have two defined on your Cellular0 interface. Get rid of one, and make sure what you add below exactly matches.

chat-script GSM "" "AT!CALL" TIMEOUT 20 "OK"

You also need a dialer-list.

dialer-list 1 protocol ip permit

And a route via the cellular interface. If you still can't get it working please post you whole config.

attached is the complete

mohdtaamneh — Mon, 07 Mar 2016 21:26:03 GMT

attached is the complete config

Did the modifications work

Philip D'Ath — Mon, 07 Mar 2016 21:27:36 GMT

Did the modifications work that I supplied?

Will try and let you know my

mohdtaamneh — Mon, 07 Mar 2016 21:41:06 GMT

Will try and let you know my feedback. but I have a question regarding the config for the controller. I can't find gsm option as my old 3G router. Is the current config under the controller should work fine with 3G sim card?

controller Cellular 0
lte modem link-recovery rssi onset-threshold -110
lte modem link-recovery monitor-timer 20
lte modem link-recovery wait-timer 10
lte modem link-recovery debounce-count 6

3G and 4G routers do not have

Philip D'Ath — Mon, 07 Mar 2016 21:44:39 GMT

3G and 4G routers do not have the same cellular configuration. Similar, but not the same.

The "Controller" config should be fine.