To use Akamai with the Vecaster or Vecoder RTMP stream you can do the following. 

Akamai usual gives you 

RTMP URL 
rtmp://p.ep75735.i.akamaientrypoint.net/EntryPoint/
RTMP Stream 
dkrlive7_1_10001@75735
RTMP Username 
101003
RTMP Password
J4wu3Z

You would have to combine it all to use with the Vecasters / Vecoder RTMP syntax

rtmp://user:pass@ip/xxx/xxx

or

Rtmp://<username>:<password>@p.ep<ID>.i.akamaientrypoint.net/EntryPoint/<STREAM_NUMBER>@<ID>    - This format has been given to us by Akamai official support. 

example,  rtmp://101003:J4wu3Z@p.ep75735.i.akamaientrypoint.net/EntryPoint/dkrlive7_1_10001@75735

See below screenshot from the encoder,  rtmp://user:pass@ip/xxx/xxx

Combine all the information provided by Akamai in the following manner: 

rtmp://101003   :   J4wu3Z@p.ep75735.i.akamaientrypoint.net/EntryPoint/dkrlive7_1_10001@75735

         USER   :  PASS   @  IP ADDRESS  /  URL  / STREAM NAME