The best replacement for forwarding is port triggering.

The best alternatives to forwarding are rated as following:
★★★★★  port triggering
★★★★  dmz
★★★  virtual server
★★★  routing
★  upnp
★  hamachi
★  nat
★  port mapping
★  conditional forwarding
★  triggering
★  pop3
★  rewinding
★  redirect
★  qos
  replying
  delegation
  masked forwarding
  cname
  port forwarding
  stub zones
  port range forwarding
  upnp ps3
  upnp forwarding
  stub zone
  open port
  switching
  vpn
  stalling
  static nat
  opening a port

Your alternative for forwarding is not listed? Suggest!
Speaking about forwarding, one probably shouldn't forget about dns.

Other search terms related to forwarding and their ratings are:
★★★★★ dns
★★★ ssh
★ nat
hosting
You have in mind a companion for forwarding and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of forwarding in all years. Click on graph for more.
forwarding
port triggering
dmz