TShark: A Protocol Analyzer

Hello there! This time we are going to explain about a network protocol analyzer called “TShark”. The TShark is a command-line version of a Wireshark. If you have already downloaded the Wireshark, you can find a Tshark execution file in a Wireshark folder.1

The Tshark can capture realtime packets along with the Wireshark. It is similar to a packet analizing software called ”tcpdump” which runs from a command-line. The Tshark uses pcap library just as tcpdump.

You can capture a packet in the command window by using the Tshark.2

We have captured a packet with a simple option. We can check that the captured packets are saved as a file in a folder. 3

You may experience overload of the Wireshark when you use it for product testing to check its status and for capturing a large amount of packets over a long period.

In that case, we use the TShark to capture packets, and analyze those packets with the Wireshark.

This is the end of this posting about Tshark! Thank you for reading! :)


How To Use Free DDNS (No-IP DDNS)

DNS is to change an IP address to a domain name such as “abc.com” to make it easy to remember. DDNS is a management service to keep this domain name linked to a changing IP address as not all computers use static IP addresses.

Most of the global companies support DDNS service and we’d like to introduce one of them: “NO-IP”.

The biggest reason to pick NO-IP is because this USA company provides free DDNS service.

Another USA company, Dyn, had been supported free DDNS service until they suddenly stopped doing this. It adversely affected our ezTCP products embedded with Dyn service and we had to find an alternative.

(We have no idea why but it seems Dyn is more popular than NO-IP according to Google search engine.)


Getting to the point, how can we use this free DDNS service of NO-IP?

Firstly, we need to create an account at http://www.noip.com/.

Click [Sign Up]!



Enter a username, password, email address, etc., and click [Free Sign Up].

Input a hostname you’d like to register in the “Hostname”. It must be unique and you’d better register something appropriate and easy to remember. If you want to create an account but register a hostname later, just click the “Create my hostname later” check box.



Once you submit your account information, an email to confirm your registration will be sent to the address you provided.



Look for the email from NO-IP and activate your account by clicking the link in the confirmation email, and finally you are able to log into the NO-IP website as a member.



Click the “Manage Hosts” icon and you will find your hostname list.



The hostname you created when you join will be presented in this list. You can add one by clicking “Add A Host” if it’s empty. You’re allowed to add up to three hostnames for each free account.



We’re done with how to create an account and register a hostname. What we are going to do next is to make our computer accessible with the hostname, not the IP address.

No-IP also supports a free update client program available on a PC. Click [Dynamic Update Client] on the left menu.



Click “Download Now” to download an exe file and start installing.



Run the program after completing the installation.

You can log on with your account by pressing the [Edit] button and choose a hostname by pressing [Edit Hosts]. The green-coloured checks represent successful update, so now you are able to access to your computer by your hostname from anywhere in the world.



Note that free hostnames expire when they are not used for 30 days. So you must update them before it becomes invalid.

Detailed instructions for installing are available in the knowledge section of NO-IP website below.



Network Protocol Analyser, Wireshark

What is Wireshark? We are looking into it today!

Wireshark is the world’s first ever network protocol analyser, which allows a user to capture and save packets as well as examining them in details.

We will now see how to install and use Wireshark.

Firstly, we need to download it at the Wireshark official website(https://www.wireshark.org/) below.



Clicking the [DOWNLOAD] on the upper left, you will move to the following page to download a install file according to the OS of your computer.

It would hardly happen to install a wrong one since it guides users to what they have to install. – “Windows Installer (32-bit)” was indicated in bold because the computer to open this website is 32-bit Windows 7.



Click the proper install file and start installing Wireshark.

Keep clicking “Next” to set it up by default unless there are any options you would like to set additionally.

wireshark_install_1 wireshark_install_2 wireshark_install_3 wireshark_install_4 wireshark_install_5


wireshark_install_7 wireshark_install_8 wireshark_install_9






Simply done.

Let’s run Wireshark!


If you click “Network Interface” and “Start”, it starts capturing packets.



We have simply looked through what Wireshark is.

This complimentary program is a fantastic and useful for anyone needs to examine data from a live network. If you are a newbie developer, you may try this one.



PoE, Power over Ethernet


Have you heard about PoE?

PoE, which stands for Power over Ethernet, is a system to supply power via a LAN cable(UTP cable) as well as to transfer data.

PoE had been used by some of network device manufacturers until it was defined under IEEE 802.3af standard in June, 2003. In 2009, it was updated to PoE+, known as IEEE 802.3at standard, to provide several enhancements to the original IEEE 802.3af specifications.

In general, a PoE hub is called to PSE(Power Sourching Equipment), and the device supplied power is called PD(Powered Device).

Unfortunately, none of our products supports PoE at the moment, but this inconvenience is easily got rid of with a PoE splitter. It lets non-PoE devices connected to the PoE network by splitting data line and power line, so all you have to do is simply connect each line to the power and LAN separately.

Also, you can implement PoE interfacing with CSE-M53(N), an embedded serial to Ethernet module. Clicking the link below and you will find all the necessary information about PoE, application schematic, required components, etc.

http://www.eztcp.com/en/download/tdocument.php [CSE-M53 PoE Interface]


It is assumed a demand for PoE will keep increasing because of convenience on installing equipment and set up PoE network.

At the beginning, it was common that PoE hubs and PoE supportive devices were expensive compared with normal network euqipment but those are now being sold at reasonable price so people use it even at home soon.


A Tip for using Free DDNS service

A Tip for using free DDNS


To use DDNS service of DynDNS
for free, 30 days trial account is the only option.


Today, I would introduce
another way to use the DDNS service for free.


Create a new account on the
site linked below.




사용자 삽입 이미지
You can log in with the
account on the homepage of DynDNS.




Two domain names are


One could be added on dyn.com
and the other on dlinkddns.com.

사용자 삽입 이미지

 Creating an account in this way is useful because it has no limitation of
trial period.