Perlmonks isn't code writing service, perhaps you could do some research on Network Programming (see also the associated network programming Q&A and Networking Code). CPAN has various server frameworks available. Also, you could also take a look at How do I post a question effectively? since you don't tell us much about what this data will be like etc. Other things to consider:

• telnet isn't very secure. You may want to look at using a secure networking protocol.
• Does the data have to stream from this other system, can't a file be transfered (securely) into your system for parsing/munging?