The best replacement for etherchannel is lacp.

The best alternatives to etherchannel are rated as following:
★★★★★  lacp
★★★  port channel
★★★  trunking
★★  link aggregation
★★  lag
★  vpc
★  pagp
★  multilink
★  lacp vmware
★  portchannel
  fiber channel
  802.3ad
  nic teaming
  port-channel

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

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



Google Trends

Scale is based on the average worldwide traffic of etherchannel in all years. Click on graph for more.
etherchannel
lacp
port channel