Hi,
I dont find same article for your question
as ref
About managed and unmanaged clients
Article:HOWTO81263
Article URL http://www.symantec.com/docs/HOWTO81263
please check in this article "unamange clients Admin user to upgrade and where it will not update from console".
and if you click on live udpate in self manage system you can see that it try to connect to www.liveudpate.sysmtecliveupdate.com on the screen as you can confirm it connect to internet for updating defintions,
Please check this link
where you can find the latest defintion released as you client will have the same date updated
http://www.symantec.com/security_response/definitions.jsp
I am sorry I tried for more than an hour could not find any direct article which email about the PTP and NTP How defintions get update for Self manage system.