The best replacement for mtu is mss.

The best alternatives to mtu are rated as following:
★★★★★  mss
★★★  ip mtu
★★  mru
★★  caterpillar
★★  frame size
★★  tcp window size
★★  nmu
★  jumbo frames
★  window size
★  uptu
★  mss cisco
★  fragmentation threshold
  1492 mtu
  datagram size
  valenta
  mtu
  packet size
  smc
  paxman valenta
  gvsu

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

Other search terms related to mtu and their ratings are:
★★★★★ ping
★★ ping linux
You have in mind a companion for mtu and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of mtu in all years. Click on graph for more.
mtu
mss
ip mtu