This topic describes how to troubleshoot the issue of "Service Unavailable" when you use Short Message Service (SMS).

Check network connectivity

Note If you use a third-party MTR tool, such as WinMTR, make sure that you have read the product documentation provided by this third party. Alibaba Cloud is not liable for the documentation and user interface (UI) of third-party products.

Select one or more application servers or containers, or select machines in the same network environment and run the following commands on the machines.

  1. Obtain the public IP address for egress traffic.
    curl ifconfig.me
  2. Check network connectivity.
    • (Recommended) Run the mtr command for 30 seconds to check network connectivity. You may need the sudo permissions.

      mtr --no-dns {Region-specific domain name of POP product} or mtr --no-dns {SMPP IP address}

    • Run the ping command for 30 seconds to check network connectivity.

      ping {Region-specific domain name of POP product} or ping {SMPP IP address}

  3. Optional:If you run the mtr command, you must install the MTR tool.
    • Install the MTR tool by running the package management command. You may need the sudo permissions.
      • For CentOS, run the yum install mtr command.
      • For Ubuntu, run the apt install mtr-tiny command.
      • For Arch Linux, run the pacman -S mtr command.
      • For Mac OS X, run the brew install mtr command. You must install Homebrew.
    • Install the MTR tool by compiling the source code.

      For more information, see MTR tool README.

    • For Windows, download WinMTR, decompress the package, and run the program.WinMTR

Submit the execution results

After you check network connectivity, enter the execution results in the feedback form and send the form to the Alibaba Cloud customer manager.

Time when network diagnostics are performed + Time zone Example: 2021-01-28 09:13 UTC+8
Command Purpose Execution result
curl ifconfig.me Obtain the public IP address for egress traffic Example: 47.89.83.92
ping {Destination domain name} or ping {Destination IP address}

Example: ping dysmsapi.ap-southeast-1.aliyuncs.com

Check network connectivity

Example:

64 bytes from 47.88.128.94: icmp_seq=0 ttl=33 time=67.357 ms

64 bytes from 47.88.128.94: icmp_seq=1 ttl=33 time=65.746 ms

64 bytes from 47.88.128.94: icmp_seq=2 ttl=33 time=66.366 ms

64 bytes from 47.88.128.94: icmp_seq=3 ttl=33 time=65.833 ms

64 bytes from 47.88.128.94: icmp_seq=4 ttl=33 time=65.817 ms

64 bytes from 47.88.128.94: icmp_seq=5 ttl=33 time=66.308 ms

64 bytes from 47.88.128.94: icmp_seq=6 ttl=33 time=65.916 ms

... ...

mtr --no-dns {Destination IP address or domain name}

Example: mtr --no-dns dysmsapi.ap-southeast-1.aliyuncs.com

Check the response time of each node and the packet loss rate

Example:

HOST Loss% Snt Last Avg Best Wrst StDev

xxx.xxx.xxx.xxx xx xx xx xx xx xx xx

xxx.xxx.xxx.xxx xx xx xx xx xx xx xx

... ...

Description

HOST Loss% Snt Last Avg Best Wrst StDev
The IP address and domain name of the node The packet loss rate of the node The number of packets sent per second The last round-trip delay (RTD) The average RTD The minimum RTD The maximum RTD The standard deviation

For more information about how to use the MTR tool and analyze the execution results, see How to use the Linux mtr command or mtr(8) - Linux man page.