Saturday, May 8, 2010

Reduce IPMSG traffic

In our college a LAN chatting/Messenger application called IPMESSENGER is pretty famous. It not only provides chatting and instant messaging facility but also supports file transfer.
It uses the UDP protocol for the the messaging and TCP for the file transfers.

Some of its unique features include:
1.It is very compact(a few KBs)
2.Does not require a server, unlike some other software.
3.Includes file transfers
4.Even though UDP(and therefore unreliable) is used, the application layer implements the TCP like features and if the message sent is not acknowledged, the software will give an error!

But there is a small problem, especially in our college where the administrator cap the bandwidth due to which the browsing does become very slow, and therefore it becomes important that we use as little bandwidth as possible and do not cause heavy traffic.

The IPmsg seems to use the Blowfish and RSA encryption which can cause the data size of simple udp datagram to increase ten-fold. On running it at my home computer a 39-bytes of data(without encryption), which contained a simple message "hi" converted to 339 bytes after encryption. On our campus the average number of students using the ipmessenger application is 250, that would mean a lot of useless traffic.

The application does not directly provide an option to turn off encryption, so you would have to do some work yourself by manually editing the registry.

a)Open regedit.
b)Go to HKEY_CURRENT_USER\Software\HSTools\IPMsgEng
c)Click on IPMsgEng on the left pane and on the right pane search for the key "EncryptNum", the default value should be 14, change that to 0.
d)Close the application and restart the computer to make sure that the registry changes have take effect.

Some important links:

1.IPmessenger home website
2.Wiki on encryption

No comments:

Post a Comment