I've installed gdb.so, configured php.ini this way :
extension=dbg.so
[debugger]
debugger.enabled=on
debugger.profiler_enabled=on
debugger.hosts_allow=ALL
debugger.JIT_enabled=on
;debugger.hosts_deny=ALL
debugger.ports=7869
debugger.fail_silently=off

and checked if dgb shows up in phpinfo() and it does :

dbg
DBG php debugger, version 2.11.32, Copyright 2001, 2005, Dmitri Dmitrienko, www.nusphere.com

Version 2.11.32
Linked as a shared library.
Profiler compiled, enabled

Directive Local Value Master Value
debugger.enable_session_cookie On On
debugger.enabled On On
debugger.fail_silently Off Off
debugger.ignore_nops Off Off
debugger.JIT_enabled On On
debugger.JIT_host clienthost clienthost
debugger.JIT_level 3 3
debugger.JIT_port 7869 7869
debugger.profiler_enabled On On
debugger.session_nocache On On
debugger.timeout_seconds 300 300

So far so good, it means that the gbd should work and I should be able to connect to 7869, right?
If so why if I try this I get this error :

Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote host: Connection refused


Thank you in advance for your time.

Alex

no, it does not mean that. DBG module (server part) is not a listener. DBG client (DbgListener.exe or dbg-cli console) plays role of listener and by running telnet on the server you may check if server is allowed to connect to the listener which is running on the client machine.