SMTP modify a character in the packet

Thank you very much.

 

 

Now, the parser is working, but I found that when I recieve the answer I need to add the 9, because of the communication with the other server is with 9, if not the answer will be "500 Command unrecognized".

 

 

I wrote:

 

set sdata [TCP::payload]

 

set digit_nine "9"

 

set find {(54)([0-9]*)(/TYPE)}

 

 

if { [regexp $find $sdata] > 0} {

 

regsub -all $find $sdata "\\1$digit_nine\\2\\3" sdata

 

TCP::payload replace 0 [string length $sdata] "$sdata"

 

}

 

 

And the error is "Jul 26 11:35:36 tmm tmm[730]: 01220001:3: TCL error: Rule remove_9_MSISDN - Out of bounds (line 1) invoked from within "TCP::payload replace 0 [string length $sdata] "$sdata"""

 

 

I know that this mean that I cannot add a new character in the payload, but then how can I do it?