What should I use as hostname for php to connect to openLDAP?

To: openldap-technical@openldap.org

Subject: What should I use as hostname for php to connect to openLDAP?

From: Jason Huang <jasonhuang5525@gmail.com>

Date: Sun, 7 Jul 2013 17:04:50 -0400

Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=Q+aLBH+iOk2AmRm4xttRfHH4dxPDnzJrvwNDYpgk4ZQ=; b=yOZHJm3S5aXrecLvVpqmUxyhhNqi7h2eDYGRQmheNDZASm0g7RNDovKfMLKIax+Q30 shkEgw4h23sIVAfQCcrXwOtvo24cDjwJrcDC22GrT8sl027oibDiIxlw/E21fSM+Q4hF 2NlMZzNUjdHqV1pVfw/dv99YJ8sSFTOOsjTwp3l6HW9py3NWIut8efdHdnoIiDV9bl+u oncoWaOlh3cmPTdu4aKtJLAOkintqZc3UjEYrwpT+VFVDTfiEREr2dDCv1bXf8doFYvf 2uel0zKn0IfJgBd4b+fTjn/6SxCoHL+dko9uh4HkpySTL6dKAeznuxr8tcRDucLK4n6/ xBZQ==

Hello - I am a newbie to openLDAP and wants to get some help here.

I've deployed apache on a EC2 server, obtain an elastic IP from amazon and point xyz.com to this IP.

I've installed a service provider(simplesamlphp) with hostname sp.xyz.com, pointing to this same IP.

I've also installed an identity provider (simplesamlphp) with hostname idp.xyz.com, pointing to this same IP.

Now I am installing openLDAP on this same server. What hostname should I use for php to connect to this ldap server? Should I use "xyz.com" or "sp.xyz.com" or "idp.xyz.com", or something else like "ldap.xyz.com"? If I am using "ldap.xyz.com", where should I specify this hostname?

thanks!