How do I check my home voicemail while away?

I would like to know how to check my home voicemail from another phone. When I am at home I simply pick up my landline and call my home phone number and it takes me directly to voicemail. But if I call from another phone it just rings at my house and does not allow me to check my voicemail. Is there another special access number that I can call to check my messages? Thanks in advance for any help or suggestions.