pecl在同一台服务器上安装没有db2的ibm_db2.so

I want to install the php-extenstion ibm_db2.so with the following command :

pecl install ibm_db2

During the installation, pecl asks for the DB2 Installation Directory. I already used this command on an other server where an db2 is installed, so there was no problem, giving him the db2 directory.

But now I need to install the extension on a server without a local installed db2. There is a website intended to run on this server with a connection to the database-server, so I need the php-commands provided by the ibm_db2.so.

Pecl still wants an installation directory. But, as I mentionend, the db2 resides on an other server.

Is it crucial to have the db2 on the same server? Or do I just use an incorrect command for installing?

If I leave the field empty and just press enter, the installation fails.