Steps to reproduce:

1. Building SIPp on CentOS 6.x: ./build.sh --with-pcap --with-rtpstream

Result:
Build fails with link error:
/opt/rh/devtoolset-3/root/usr/libexec/gcc/x86_64-redhat-linux/4.9.2/ld: src/sipp-screen.o: undefined reference to symbol 'stdscr'

Workaround:
Add -ltinfo to Makefile:
LIBS = -lpcap -lm -lpthread -lrt -ldl -lncurses -ltinfo