The best replacement for tcp is udp.

The best alternatives to tcp are rated as following:
★★★★★  udp
★★★★  ip
★★★  lcp
★★  http
★★  osi
★★  udp port
★  udp ports
★  upd
★  ruger lcp
★  ucp
★  udp protocol
★  udp vpn
★  udp faster
★  udp speed
★  bodyguard
★  sctp
★  udp performance
  icmp
  udp protocols
  cree
  udp security
  socket
  ipx
  udp wiki
  utp
  kel tec p3at
  cw380
  udp remote desktop
  websocket
  udp streaming
  multicast
  http performance
  tcp
  modbus rtu
  tls
  ip protocol
  telnet
  osi model
  udp traffic

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

Other search terms related to tcp and their ratings are:
★★★★★ ip
★★★ ecn
★★ udp
★★ rtp
nfs
You have in mind a companion for tcp and it is not yet here? Propose!



Google Trends

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