某局点MSR设备4G拨号获取不到地址，向运营商注册失败

MSR3640设备从原来的0306P52版本升级到0821P18版本后拨号异常，接口物理状态up，协议down。

从现场看可能是重启之后再次注册，由于某些原因注册不上。该问题与升级版本毫无关系。

 通过命令dis cell查看注册情况：

dis cellular

Cellular1/0:

Modem State:

  Hardware Information:

    Model: U8300C

    Manufacturer: LONGSUNG

    Modem Firmware Version: QA30002.1.6_MV11(4534_1.2.3_L0801)

    International Mobile Equipment Identity (IMEI): 86975XXXXXXXXX

    International Mobile Subscriber Identity (IMSI): 46001XXXXXXXXX

    Mobile Equipment Identifier (MEID): A100005B1427A0

    Hardware Version: 30000

    Factory Serial Number (FSN): SA300066477M00148

    Modem Status: Online

    Modem Status: IPv4 Unkown.

    Modem Status: IPv6 Unkown.

  Profile Information:

    Profile index: 1 

      PDP Type: IPv4v6

      Header Compression: Off

      Data Compression: Off

      Access Point Name (APN): SHILI.TEST

      Authentication: CHAP

      Username: test@123

  * - Default profile

  Network Information:

    Current Service Status: Limited  注册不上，状态受限

    Registration Status: Denied        运营商拒绝接入

    Current Roaming Status: Roaming

    Current Data Bearer Technology: Unknown

    Network Selection Mode: Automatic

    Current IP address Mode: Cellular-alloc

    Current IPV6 address Mode: Unknown

    Mobile Country Code (MCC): 460

    Mobile Network Code (MNC): 00

  Radio Information:

    Technology Preference: LTE only  4G接入

    Technology Selected: LTE

    Configured LTE Band: 1,3,5,38,39,40,41

  LTE related info:

    Current RSSI: -46 dBm

    Current RSRQ: -8 dB

    Current RSRP: -72 dBm

    Current SNR: 29 dB

    Tx Power: Invalid

    Active Band: E-UTRA Operating Band 3

  Modem Security Information:

    PIN Verification: Disabled

    PIN Status: PIN Requirement Disabled

    Number of PIN Retries Remaining: 3

    Number of PUK Retries Remaining: 10

    SIM Status: OK

        ICCID: 898601137XXXXXXXXXXX

  Error Information:

    IPv4 dialing failed: N/A

    IPv6 dialing failed: N/A 

plmn测试可以接入的运营商网络，发现4G本来就不能接入。

[MSR-Cellular1/0]plmn search

PLMN search done.

 Available PLMNs:

PLMN NO.    MCC    MNC      Status       Type

    01       460    01       Available    LTE network

    02       460    01       Available    UMTS network

    03       460    00       Forbidden    GSM network

    04       460    00       Forbidden    LTE network   

    05       460    15       Available    LTE network

    06       460    11       Available    LTE network

    07       460    29       Available    LTE network

联系最终客户确认，该卡本来就不支持4G，只开通了3G业务。

修改modem模式为WCDMA后恢复正常。

配置命令:

[Sysname] controller cellular 1/0

[Sysname-Cellular2/4/0] mode wcdma