Quectel EC20 4G module dial related

1.ec20dial method

The following is an excerpt from Quectel's documentation:

有2method to startppp拨号

方式1： 拷贝 quectel-chat-connect quectel-chat-disconnect quectel-ppp 到 /etc/ppp/peers 目录下.

并在 quectel-ppp Modify your serial device name here,pppd used for dialing username,password.

在 quectel-chat-connect to modify yours APN.APN/username/password is obtained from your network provider.

然后使用下面的命令启动 ppp 拨号, 命令最后的 & 可以让 pppd 后台运行

pppd call quectel-ppp &



方式2：使用quectel-pppd.sh 拨号,命令形式如下:

./quectel-pppd.sh 串口设备名(比如/dev/ttyUSB3) APN username password



ip-up：pppd 在获取 ip 和 dns 之后,This script file is automatically called to set up the system DNS

Embedded systems generally need to copy this file to  /etc/ppp 目录下.
Make sure the file has executable permissions on your system.



quectel-ppp-kill Used to hang up dialing,pppdMust be hung up normally,Otherwise it may cause you next timeppp拨号失败.

Use the following method to call this script

./quectel-ppp-kill 

2.ec20模块ppp拨号流程

3.Dial was successful but notping通外网

The dialing was successful but not connectedppp0设置为静态路由.设置PPP0为默认路由：Delete the original route first,route del default 再将ppp0设置为默认路由,route add default dev ppp0
为了实现自动设置ppp0为默认路由,我的方法是在/etc/ppp/ip-up脚本里添加

[email protected]:/etc/ppp# cat ip-up
#!/bin/sh

if [ -f /etc/ppp/resolv.conf ]; then
        cp /etc/ppp/resolv.conf /etc/resolv.conf
elif [ -f /var/run/ppp/resolv.conf ]; then
        cp /var/run/ppp/resolv.conf /etc/resolv.conf
else
        echo nameserver $DNS1 > /etc/resolv.conf
        echo nameserver $DNS2 >> /etc/resolv.conf
fi
route del default #Delete the original route
route add default dev ppp0 #设置ppp0为默认路由

Check routing information after dialing is successful:

n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         0.0.0.0         0.0.0.0         U     0      0        0 ppp0
10.5.112.0      0.0.0.0         255.255.255.0   U     0      0        0 eth0
10.64.64.64     0.0.0.0         255.255.255.255 UH    0      0        0 ppp0
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0

可见,ppp0The routing information has been added successfully,这时候再ping www.baidu.com,成功

64 bytes from 36.152.44.96 (36.152.44.96): icmp_seq=14 ttl=54 time=33.2 ms
64 bytes from 36.152.44.96 (36.152.44.96): icmp_seq=15 ttl=54 time=41.2 ms

4.关于ip-up和ip-up.d的说明

1. /etc/ppp/ip-up 由 ppp 套件 提供
1-1. sudo dpkg -S /etc/ppp/ip-up
ppp: /etc/ppp/ip-up

2. /etc/ppp/ip-up.d 可以由
ppp, resolvconf, pppconfig, pppoeconf, gogoc
Either kit is available
2-1. sudo dpkg -S /etc/ppp/ip-up.d
ppp, resolvconf, pppconfig, pppoeconf, gogoc: /etc/ppp/ip-up.d

3. /etc/ppp/ip-up 是 檔案; /etc/ppp/ip-up.d 是 目錄
3-1. sudo ls -Al /etc/ppp | grep ip-up
-rwxr-xr-x 1 root root 1892 2月 4 2011 ip-up
drwxr-xr-x 2 root root 4096 7月 24 12:53 ip-up.d
3-2. sudo ls -Al /etc/ppp/ip-up.d
-rwxr-xr-x 1 root root 902 2月 4 2011 0000usepeerdns
-rwxr-xr-x 1 root root 553 6月 4 2015 000resolvconf
-rwxr-xr-x 1 root root 4022 10月 24 2015 0dns-up
-rwxr-xr-x 1 root root 148 3月 30 2010 gogoc

4. 都是 可執行 script file
4-1. sudo cat /etc/ppp/ip-up
#!/bin/sh
以下省略
4-2. sudo cat /etc/ppp/ip-up.d/0000usepeerdns
#!/bin/sh -e
以下省略

5.关闭ppp0The default route of Ethernet is restored after connection,Otherwise, Ethernet will not work(???)

My solution to this problem is in ip-downadded to the scriptservice networking restart
修改后的ip-down脚本如下

[email protected]:/etc/ppp# cat ip-down
#!/bin/sh
#
# This script is run by the pppd _after_ the link is brought down.
# It uses run-parts to run scripts in /etc/ppp/ip-down.d, so to delete
# routes, unset IP addresses etc. you should create script(s) there.
#
# Be aware that other packages may include /etc/ppp/ip-down.d scripts (named
# after that package), so choose local script names with that in mind.
#
# This script is called with the following arguments:
# Arg Name Example
# $1 Interface name ppp0
# $2 The tty ttyS1
# $3 The link speed 38400
# $4 Local IP number 12.34.56.78
# $5 Peer IP number 12.34.56.99
# $6 Optional ``ipparam'' value foo

# The environment is cleared before executing this script
# so the path must be reset
PATH=/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin
export PATH

# These variables are for the use of the scripts run by run-parts
PPP_IFACE="$1"
PPP_TTY="$2"
PPP_SPEED="$3"
PPP_LOCAL="$4"
PPP_REMOTE="$5"
PPP_IPPARAM="$6"
export PPP_IFACE PPP_TTY PPP_SPEED PPP_LOCAL PPP_REMOTE PPP_IPPARAM

# as an additional convenience, $PPP_TTYNAME is set to the tty name,
# stripped of /dev/ (if present) for easier matching.
PPP_TTYNAME=`/usr/bin/basename "$2"`
export PPP_TTYNAME 

# If /var/log/ppp-ipupdown.log exists use it for logging.
if [ -e /var/log/ppp-ipupdown.log ]; then
  exec >> /var/log/ppp-ipupdown.log 2>&1
  echo $0 [email protected]
  echo
fi

# This script can be used to override the .d files supplied by other packages.
if [ -x /etc/ppp/ip-down.local ]; then
  exec /etc/ppp/ip-down.local "[email protected]"
fi

run-parts /etc/ppp/ip-down.d \
  --arg="$1" --arg="$2" --arg="$3" --arg="$4" --arg="$5" --arg="$6"
service networking restart

Check the routing information as follows:

[email protected]:/etc/ppp# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.5.112.254    0.0.0.0         UG    0      0        0 eth0
10.5.112.0      0.0.0.0         255.255.255.0   U     0      0        0 eth0
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0

It can be seen that it has been restoredeth0的默认路由