Hi, I have no aliases configured. I found out after debugging mysql, that domain was not in the request string. select password,domn,uuid,rpid from subscriber where username='<user-b>' should'nt the domain be in the request??? I modified my config: #modparam("auth_db", "calculate_ha1", 1) #modparam("auth_db", "password_column", "password") Having only <user-a>@<domain-a> in my subscriber database, I cannot register <user-a>@<domain-b> This works as I would like. However, Adding <user-a>@<domain-b> does not allow me to register <user-a>@<domain-b>... best regards, hw Message: 2 Date: Wed, 19 Jan 2005 09:32:11 -0300 From: Felipe Martins &lt;fmartins(a)mundivox.com&gt; Subject: Re: [Serusers] SER-0.9.0 Multiple-domain To: serusers(a)lists.iptel.org Message-ID: &lt;20050119093211.2e93c9ab(a)numenor.mundivox.com&gt; Content-Type: text/plain; charset=US-ASCII If I'm not misundertood , you can register your users even if there is just one SIP_DOMAIN configured, you want only the fist one (domain-a) to register, but domain-b can register even though. Check your aliases, see if domain-b is configured like an alias.