$ sudo apt-get update
$ sudo apt-get install libexosip2-11 

libexosip2-11 is installed in your system.

Make ensure the libexosip2-11 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libexosip2-11 *

You will get with libexosip2-11 package name, version, architecture and description in a table

libexosip2-11 package basic information: