Cellulor port flapping , 3G port

Publication Date:  2014-08-05 Views:  302 Downloads:  0
Issue Description
cellulor interface was coming up and then going down .

PPP link was closed after few minutes .

Jul 31 2014 21:41:19+00:00 Huawei %%01PPP/4/PHYSICALDOWN(l)[10]:On the interface Cellular0/0/0, PPP link was closed because the status of the physical layer was Down
Alarm Information
[Huawei]

Jul 31 2014 21:41:19+00:00 Huawei %%01PPP/4/PHYSICALDOWN(l)[10]:On the interface Cellular0/0/0, PPP link was closed because the status of the physical layer was Down.

[Huawei]

Jul 31 2014 21:41:19+00:00 Huawei %%01IFNET/4/LINK_STATE(l)[11]:The line protocol PPP on the interface Cellular0/0/0 has entered the DOWN state.

[Huawei]

Jul 31 2014 21:41:19+00:00 Huawei %%01IFPDT/4/IF_STATE(l)[12]:Interface Cellular0/0/0 has turned into DOWN state.

[Huawei]quit

<Huawei>q [1D  [1D  debugg

<Huawei>debugging ppp all

<Huawei>debugg

Jul 31 2014 21:41:30+00:00 Huawei %%01IFPDT/4/IF_STATE(l)[13]:Interface Cellular0/0/0 has turned into UP state.

<Huawei>debugg

Jul 31 2014 21:41:30+00:00 Huawei %%01IFNET/4/LINK_STATE(l)[14]:The line protocol PPP on the interface Cellular0/0/0 has entered the UP state.
Handling Process
After examining the scenario and discussion with customer team ,

following info we got

1) SIM was in roaming mode
2) SIM was using 2G mode and not support 3G mode
3) Network has to be manually defined

To support all above points , we need to change the mode of SIM from WCDMA to GSM .( or you can say from 3G to 2G )
Root Cause
we tried following stuff

1) different versions
2) different routers
3) different SIM
4) different location as well

Not able to find any problem in any of these , as same SIM is working fine in mobile.
Suggestions
[Huawei] interface cellular 0/0/0
[Huawei-Cellular0/0/0] mode wcdma gsm-only

Suggestions:

Before using SIM in router , make sure to ask customer which mode he want to use 3G or 2G .
This information is available with customer but we have to ask for it .

END