telent: strange char at start connection. Please help me!

Hallo,
I find a library very userfull form connect by telnet.
Just a question:

The library sends strange data: why? what is userfull for these data?
I mean these:


[...]
$this->conn1=chr(0xFF).chr(0xFB).chr(0x1F).chr(0xFF).chr (0xFB).
chr(0x20).chr(0xFF).chr(0xFB).chr(0x18).chr(0xFF). chr(0xFB).
chr(0x27).chr(0xFF).chr(0xFD).chr(0x01).chr(0xFF). chr(0xFB).
chr(0x03).chr(0xFF).chr(0xFD).chr(0x03).chr(0xFF). chr(0xFC).
chr(0x23).chr(0xFF).chr(0xFC).chr(0x24).chr(0xFF). chr(0xFA).
chr(0x1F).chr(0x00).chr(0x50).chr(0x00).chr(0x18). chr(0xFF).
chr(0xF0).chr(0xFF).chr(0xFA).chr(0x20).chr(0x00). chr(0x33).
chr(0x38).chr(0x34).chr(0x30).chr(0x30).chr(0x2C). chr(0x33).
chr(0x38).chr(0x34).chr(0x30).chr(0x30).chr(0xFF). chr(0xF0).
chr(0xFF).chr(0xFA).chr(0x27).chr(0x00).chr(0xFF). chr(0xF0).
chr(0xFF).chr(0xFA).chr(0x18).chr(0x00).chr(0x58). chr(0x54).
chr(0x45).chr(0x52).chr(0x4D).chr(0xFF).chr(0xF0);
$this->conn2=chr(0xFF).chr(0xFC).chr(0x01).chr(0xFF).chr (0xFC).
chr(0x22).chr(0xFF).chr(0xFE).chr(0x05).chr(0xFF). chr(0xFC).chr(0x21);

[...]
$this->fp=fsockopen($ip,23)
fputs($this->fp,$this->conn1);
fputs($this->fp,$this->conn2);
[...]


why to send $this->conn1 and $this->fp?
What is userfull for?

Thank you in advance for the time you'l spend for me!
Mario.

Hi,

The message you're seeing is an "Interpret As Command" sequence that
sets up various options and initiates certain commands on the telnet
connection. See RFC854 (Telnet Command Structure):

http://www.ietf.org/rfc/rfc0854.txt

For instance, 0xFF 0xFB 0x1F probably enables the NAWS option that
allows a client to convey window size to a telnet server:

http://www.ietf.org/rfc/rfc1073.txt

_mario.lat wrote:
> Hallo,
> I find a library very userfull form connect by telnet.
> Just a question:
>
> The library sends strange data: why? what is userfull for these data?
> I mean these:
>
>
> [...]
> $this->conn1=chr(0xFF).chr(0xFB).chr(0x1F).chr(0xFF).chr (0xFB).
> chr(0x20).chr(0xFF).chr(0xFB).chr(0x18).chr(0xFF). chr(0xFB).
> chr(0x27).chr(0xFF).chr(0xFD).chr(0x01).chr(0xFF). chr(0xFB).
> chr(0x03).chr(0xFF).chr(0xFD).chr(0x03).chr(0xFF). chr(0xFC).
> chr(0x23).chr(0xFF).chr(0xFC).chr(0x24).chr(0xFF). chr(0xFA).
> chr(0x1F).chr(0x00).chr(0x50).chr(0x00).chr(0x18). chr(0xFF).
> chr(0xF0).chr(0xFF).chr(0xFA).chr(0x20).chr(0x00). chr(0x33).
> chr(0x38).chr(0x34).chr(0x30).chr(0x30).chr(0x2C). chr(0x33).
> chr(0x38).chr(0x34).chr(0x30).chr(0x30).chr(0xFF). chr(0xF0).
> chr(0xFF).chr(0xFA).chr(0x27).chr(0x00).chr(0xFF). chr(0xF0).
> chr(0xFF).chr(0xFA).chr(0x18).chr(0x00).chr(0x58). chr(0x54).
> chr(0x45).chr(0x52).chr(0x4D).chr(0xFF).chr(0xF0);
> $this->conn2=chr(0xFF).chr(0xFC).chr(0x01).chr(0xFF).chr (0xFC).
> chr(0x22).chr(0xFF).chr(0xFE).chr(0x05).chr(0xFF). chr(0xFC).chr(0x21);
>
> [...]
> $this->fp=fsockopen($ip,23)
> fputs($this->fp,$this->conn1);
> fputs($this->fp,$this->conn2);
> [...]
>
>
> why to send $this->conn1 and $this->fp?
> What is userfull for?
>
> Thank you in advance for the time you'l spend for me!
> Mario.