diff --git a/prototype/README.md b/prototype/README.md
index 9ce3d75..e4e819c 100644
--- a/prototype/README.md
+++ b/prototype/README.md
@@ -9,11 +9,12 @@ This script requires following modules to be installed from CPAN:
 * Net::Pcap
 * Net::Frame
 * Net::Packet::Layer7
+* Net::SIP
 
 
 # pcaputil.pl
 
-Generates gnuplot definition file from a PCAP file to draw BPS and PPS graphs
+Generates [gnuplot](http://www.gnuplot.info/) definition file from a PCAP file to draw BPS and PPS graphs
 
 ## requirements