I just bought Dragon Age: I recently, and i have problems to play with friends

I tried to play the game via Steam, but when i invited my friends to play, they can't join to my server, and we tried in quick match, but nothing changed. And then show de window message of "Connection Lost".
How can i play online with friends? I really want to play this game.

Saludos, intento jugar online con mis amigo onlina via Steam, pero no deja que nos conectemos, quisiera saber si existe algun modo de solucionarlo o a que se deben las dificultades de ese problema. Espero me puedan ayudar, siempre carga los datos, pero muestra el mensaje de "Conexion perdida". Por favor ayudenme.