If you ever used attcp before - you may have some old port numbers in your /etc/services.
If you do, the easiest resolution will be to uninstall attcp, and then remove all the ttcp lines you find in /etc/services.
FYI: the old port numbers were 55000, 55001 and 55002 (iirc). ttcp (from 1980's) used port # 5500, and I just added a digit - originally, as port 5500 is now officially assigned to something else by IANA.
Some 'debug' info:
michael@x071.home.local:[/home/michael]grep ttcp /etc/services /etc/inetd.con>
/etc/services:ttcpr 32765/tcp # ttcp_reader or sink
/etc/services:ttcpr 32765/udp # ttcp_reader or sink
/etc/services:ttcps 32766/tcp # ttcp_sender faucet
/etc/services:ttcps 32766/udp # ttcp_sender faucet
/etc/services:ttcp 32767/tcp # ttcp port holder
/etc/services:ttcp 32767/udp # ttcp port holder
/etc/inetd.conf:ttcpr stream tcp nowait nobody /opt/bin/ttcpr ttcpr
/etc/inetd.conf:ttcps stream tcp nowait nobody /opt/bin/ttcps ttcps
/opt/bin/speedto:/opt/bin/attcp -p 32765 -f M -x -i 10 -h $*
michael@x071.home.local:[/home/michael]lssrc -s inetd -l | grep ttcp
michael@x071.home.local:[/home/michael]lssrc -s inetd -l
0513-019 System Resource Controller requires that you be running as
root or be part of the group system for local requests.
michael@x071.home.local:[/home/michael]su
root's Password:
michael@x071.home.local:[/home/michael]lssrc -s inetd -l | grep ttcp
ttcps /opt/bin/ttcps ttcps active
ttcpr /opt/bin/ttcpr ttcpr active
michael@x071.home.local:[/home/michael]
p.s. I am debugging version 0.6.6 which will have 'multi-threaded' connections - to help saturate the line.