Linux TCP/IP Tuning parameters

I've noticed the the TCP/IP tuning parameters for Redhat in /etc/sysctl.conf from the Procedure Generator are different from those shown in the "8.0 SPI Performance Optimization Planning Guide" (page 54) and "Configuring TCP Networks and Network Firewalls for EMC Networker" (page 21).  Also the Procedure Generator version has some additional items such as net.ipv4.tcp_max_syn_backlog and keepalive's.

So it's hard to know what to do.