ISUP Messages Window in Wireshark

Wireshark can be defined as computer software to analyze network protocols for checking the security of any network. It was designed mainly for checking and resolving network problems. It is open-source software that can be easily downloaded from its official site. It is a very helpful tool for capturing data packets and analyzing them for finding vulnerabilities in the network if any. It also provides an option to export captured data in different formats like XML, plain text, CSV, etc. It is a very popular tool that has around 4 lakhs downloads every month.

• ISUP or Integrated Service User Part can be understood as an essential component of a signaling system that is used in making telephone calls. Making a telephone call is a complex process at the backend which a user does not understand but as a network engineer one can understand that a lot of messages are sent from one end to another before connecting a call for checking several parameters like the stability of the network, other user is free or not, the call is placed locally or internationally, codes, etc. This is done with the help of ISUP messages.
• ISUP Messages are a special type of message which contains useful information known as circuit identification codes. Circuit identification code contains information like call destination along with time slot and trunk.

ISUP Messages Window in Wireshark:

It is a window in Wireshark that allows the user to analyze telephone signals used in establishing telephone calls, these signals could be either voiced or non-voiced. Messages can be filtered on the basis of count and direction. Wireshark places all the ISUP messages data in the ISUP messages window for deep analysis of different fields like Count, Min, Max value, rate, percentage, etc.

It can be found under the Telephony tab in Wireshark, see the below image.

After it clicks on ISUP messages, the below window appears with captured ISUP messages if any.

A lot of information can be gathered from here like 

• Topic/Item: It shows the information about address messages like IAM (Initial Address Message), SAM (Subsequent address message), ACM (Address Complete Message ) etc.
• Count: It shows the count of different ISUP messages captured in Wireshark.
• Average: It depicts an average value for each corresponding packet.
• Min Val: It is used to depict the lower limit of signal for each packet, which gives an idea about the strength.
• Max Val: It shows the upper limit of signal for each ISUP message packet.
• Rate: It is used to show the transfer rate of bits, which is used in checking the stability of the signal.
• Percent: It shows the percentage of data of each ISUP message packet.
• Burst Rate: It is the maximum capacity of transmitting data in a specified time span.
• Burst Start: It is the time point when a burst starts.

Let’s understand using captured data

Here we can see that M3UA protocol is used, which is the part of ISUP which is used in signaling devices for making calls.

Conclusion:

We can conclude that ISUP is used in establishing communication among devices with the help of different protocols.