$ perl -e '
> $maxMsgCodeLength = 15;
> $port = 9000;
> $ip = q{192.168.106.60};
> $msgCode = q{StartBE};
> $msg = pack qq{A${maxMsgCodeLength}ia*}, $msgCode, $port, $ip;
> print $msg;' | hexdump -C  
00000000  53 74 61 72 74 42 45 20  20 20 20 20 20 20 20 28  |StartBE        (|
00000010  23 00 00 31 39 32 2e 31  36 38 2e 31 30 36 2e 36  |#..192.168.106.6|
00000020  30                                                |0|
00000021
$