Hello m_jaser,

According to this line in your output,

configure: error: no acceptable C compiler found in $PATH
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you don't have a C compiler installed (which is needed by Device::SerialPort). Some (but not all) modules require a C compiler.

Module names are case-sensitive. So, your attempts to install Net::SSH and Net::Telnet failed because cpan could not find the modules. Also, you should not need to use the -f flag in most cases. After you install a C compiler, you may want to try the following.

cpan -i Net::SSH
cpan -i Net::Telnet
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If you want more specific advice on how to fix these problems, then please let us know which operating system you are running and which version of perl you are running.