开发板pppd一拨号成功就断掉

[mx_linux]

连接好开发板后进行pppd拨号，会有两个问题。
第一、拨号失败。打印信息如下
send (AT^M)
expect (OK)
^M
OK
-- got it

send (AT+CGDCONT=1,"IP","3GNET"^M)
expect (OK)
^M
^M
OK
-- got it

send (ATDT*99#^M)
expect (CONNECT)
^M
^M
CONNECT
-- got it
Script /mnt/chat -v -s "" "AT" "OK" "AT+CGDCONT=1,\"IP\",\"3GNET\"" "OK" "ATDT*99#" "CONNECT" finished (pid 23005), status = 0x0
Serial connection established.
using channel 56
Using interface ppp0
Connect: ppp0 <--> /dev/ttyUSB0
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x6240e5fa> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <accomp> <pcomp> <asyncmap 0x0> <mru 1500> <magic 0x545> <auth chap MD5>]
sent [LCP ConfAck id=0x1 <accomp> <pcomp> <asyncmap 0x0> <mru 1500> <magic 0x545> <auth chap MD5>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x6240e5fa> <pcomp> <accomp>]
rcvd [CHAP Challenge id=0x1 <18f9af9360066f2e553cfe6ab7c73eff>, name = "HUAWEI_CHAP_SRVR"]
sent [CHAP Response id=0x1 <07d18466a1d269b53fa31164cd906a09>, name = "card"]
rcvd [CHAP Success id=0x1 "Welcome!!"]
CHAP authentication succeeded: Welcome!!
CHAP authentication succeeded
sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
sent [IPCP ConfReq id=0x1 <compress VJ 0f 00> <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
rcvd [IPCP ConfReq id=0x1]
sent [IPCP ConfNak id=0x1 <addr 0.0.0.0>]
rcvd [LCP ProtRej id=0x2 80 fd 01 01 00 0f 1a 04 78 00 18 04 78 00 15 03 2f]
Protocol-Reject for 'Compression Control Protocol' (0x80fd) received
rcvd [LCP TermReq id=0x2]
LCP terminated by peer
sent [LCP TermAck id=0x2]
rcvd [IPCP ConfNak id=0x1]
Discarded non-LCP packet when LCP not open
Modem hangup
Connection terminated.

第二、有时插拔一下4G模块，可以实现拨号成功，但是会立即断掉。打印信息如下。
Script /etc/ppp/peers/wcdma-chat-connect finished (pid 28058), status = 0x0
Serial connection established.
using channel 62
Using interface ppp0
Connect: ppp0 <--> /dev/ttyUSB0
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x2060e4be> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <accomp> <pcomp> <asyncmap 0x0> <mru 1500> <magic 0x543> <auth chap MD5>]
sent [LCP ConfAck id=0x1 <accomp> <pcomp> <asyncmap 0x0> <mru 1500> <magic 0x543> <auth chap MD5>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x2060e4be> <pcomp> <accomp>]
rcvd [CHAP Challenge id=0x1 <32ac368c400df2fdec5f905c2c705e63>, name = "HUAWEI_CHAP_SRVR"]
sent [CHAP Response id=0x1 <fa4b6200a44b4d8df68db1af60c0ff8c>, name = "card"]
rcvd [CHAP Success id=0x1 "Welcome!!"]
CHAP authentication succeeded: Welcome!!
CHAP authentication succeeded
sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
rcvd [IPCP ConfReq id=0x1]
sent [IPCP ConfNak id=0x1 <addr 0.0.0.0>]
rcvd [IPCP ConfNak id=0x1]
sent [IPCP ConfReq id=0x2 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
rcvd [IPCP ConfReq id=0x2]
sent [IPCP ConfAck id=0x2]
rcvd [IPCP ConfNak id=0x2 <addr 10.72.125.197> <ms-dns1 210.22.70.3> <ms-dns2 210.22.84.3>]
sent [IPCP ConfReq id=0x3 <addr 10.72.125.197> <ms-dns1 210.22.70.3> <ms-dns2 210.22.84.3>]
rcvd [IPCP ConfAck id=0x3 <addr 10.72.125.197> <ms-dns1 210.22.70.3> <ms-dns2 210.22.84.3>]
Could not determine remote IP address: defaulting to 10.64.64.64
local IP address 10.72.125.197
remote IP address 10.64.64.64
primary DNS address 210.22.70.3
secondary DNS address 210.22.84.3
Killed

就是最后一句，因为出现了DNS和IP，所以拨号显示成功，但是一秒后就断掉了，这个问题困扰了好久，请问大神们，为什么呀。

[mx_linux]

第一个问题是因为插上4G模块后需要等待一段时间才可以拨号，但是第二个问题一直不能解决，只要一拨号成功，就会断掉

[mx_linux]

第二个问题是由于未杀掉公司自带的相关程序 导致 killall Sofia ; rmmmod hi_wdt; 此时拨号就不会再断掉

[mx_linux]

对了 第一个问题，等待十分钟是由于 华为4G模块设置的自动连接且连接10分钟导致，所以，把网卡插到电脑上，在自动打开的网页上设置关闭自动连接即可，此时一插上4G模块，就可以实现拨号了