Strongly, strongly, strongly disagree.
I've got some issues with my family. Some days even an email feels like an intrusion. A phone call at work would be so over the line that there's no way I'd be willing to even consider a relationship. It would take time away from my job - and it would upset me which isn't good at work.
Email is okay, letter is okay.
I agree with others who suggest sending a letter and stating what you'd like (a relationship) and the apology.
It also may be there isn't much to come back to on his part. I'm reaching the point with my mother that although she wants a relationship, I think I just don't and it's better for me to just let that go entirely. It depends a lot on the past history whether it's worth it to the person cutting ties to open back up. In some cases the past history is just too much, in which case, respect his wishes and back off. But I do think cards/emails is an okay start. I'd stay FAR away from the phone though.
And I'd also suggest going slow. If there's been no contact for 8 years, starting up with monthly cards may feel like an intrusion. Maybe start with card or email every few months (unless you get a good response back).
Good luck to you.
I do sympathize with you. One suggestion is that if you want to resume contact, you also WILL need to listen to his reasons for cutting contact and make changes (if you're willing) to keep that contact. For me, I hear a lot of talk but don't see changes, so I'm giving up and the option to make changes is (I think) over.