MSR36 5G拨号失败问题经验案例

某局点MSR3640路由器SIC-5G子卡拨电信5G，获取不到ip地址。

查看设备dis cellular信息，信号切换到3G了，说明5G拨号失败。

[H3C]display cellular 1/0

Cellular1/0:

 Modem State:

  Hardware Information:

    Model: RM500QGL_VH

……

  Radio Information:

    Technology Preference: No preference specified (AUTO)

    Technology Selected: UMTS

    Configured LTE Band: 1,2,3,4,5,7,8,12,13,14,17,18,19,20,25,26,28,29,30,32,34,38,39,40,41,42,43,46,48,66,71

Configured NR Band: 28

手动强制拨5G，重启modem，仍拨号失败，日志显示状态为limited。信号强度-97dBm较弱，但还在可以用的范围内，请现场调整天线位置和角度，信号强度无明显改善。

继续检查dis cellular信息，发现NR Band 28有异常。N28是广电频段，现场使用的是电信卡，拨号会有问题。经现场确认，之前手工指定过band n28。

[H3C]controller Cellular 1/0

[H3C-Cellular1/0]mode nr

[H3C-Cellular1/0]modem reboot

<H3C>dis cellular

Cellular1/0:

……

  Radio Information:

    Technology Preference: NR only

    Technology Selected: NR

    Configured LTE Band: 1,2,3,4,5,7,8,12,13,14,17,18,19,20,25,26,28,29,30,32,34,38,39,40,41,42,43,46,48,66,71

    Configured NR Band: 28

  NR related info:

    Current RSRQ: -17 dB

    Current RSRP: -97 dBm

    Current SNR: -50 dB

    Current NR MODE: NONE

    Active Band: NR Operating Band 28

%May  6 14:56:27:889 2022 H3C CELLULAR/5/CELLULAR:

 Controller Cellular1/0: Service status changed from No Service to Limited.

Undo band后，重启modem，拨号正常。

[H3C-Cellular1/0]undo nr band

[H3C-Cellular1/0]modem reboot

%May  6 15:32:32:630 2022 H3C CELLULAR/5/CELLULAR:

 Controller Cellular1/0: Service status changed from No Service to Service Available.

%May  6 15:32:32:630 2022 H3C CELLULAR/5/CELLULAR:

 Controller Cellular1/0: The network connection switched to NR.

%May  6 15:32:38:702 2022 H3C IFNET/3/PHY_UPDOWN: Physical state on the interface Eth-channel1/0:0 changed to up.

%May  6 15:32:38:703 2022 H3C IFNET/5/LINK_UPDOWN: Line protocol state on the interface Eth-channel1/0:0 changed to up.

[H3C-Cellular1/0]dis cellular

Cellular1/0:

 Modem State:

  Hardware Information:

……

  Network Information:

    Current Service Status: Service Available

    Registration Status: Registered

    Current Service: Packet-switched

    Current Roaming Status: Home

    Current Data Bearer Technology: Unknown

    Network Selection Mode: Automatic

    Current IP address Mode: Cellular-alloc

    Current IPV6 address Mode: Unknown

    Mobile Network Name: CHN-UNICOM

    Mobile Country Code (MCC): 460

    Mobile Network Code (MNC): 01

  Radio Information:

    Technology Preference: NR only

    Technology Selected: NR

    Configured LTE Band: 1,2,3,4,5,7,8,12,13,14,17,18,19,20,25,26,28,29,30,32,34,38,39,40,41,42,43,46,48,66,71

    Configured NR Band: 1,2,3,5,7,8,12,20,28,38,40,41,48,66,71,77,78,79

  NR related info:

    Current RSRQ: -12 dB

    Current RSRP: -97 dBm

    Current SNR: 10 dB

Current NR MODE: NONE

指定nr band n78，或undo nr band不指定频段，可以正常拨号。

附运营商5G频段支持情况：

移动n41、n79，广电n79、n28，电信&联通n78。