Re: MyPBX for Android and noip
Ahh, now I got you 
So the question is, if myPBX for Android allows you to supply a DNS name as gatekeeper address.
And the answer is: yes and no. It is not done for H.323 unfortunately, it is done however for SIP. The android will first query for a SIP SRV record (which will probably not be present in your DynDNS DNS). if this fails, it will query the raw A record for the name you configured and connect to this.
So if you put mydomain.ddns.net as Proxy you'd need a port forward on 5060 (assuming you use TSIP, for SIPS it'd be 5061 as far as I remember) to your PBX and it should work.
I tried the domain-name based SIP registration to a PBX with an alpha v12r1 android, but I believe it should work with v11r2 the same way. You can even use a non-standard port (which I would recommend to fool SIP port scanners) and use mydomain.ddns.net:yourport.
Keep in mind that opening SIP registrations to the public is dangerous.
Regards, Christoph

So the question is, if myPBX for Android allows you to supply a DNS name as gatekeeper address.
And the answer is: yes and no. It is not done for H.323 unfortunately, it is done however for SIP. The android will first query for a SIP SRV record (which will probably not be present in your DynDNS DNS). if this fails, it will query the raw A record for the name you configured and connect to this.
So if you put mydomain.ddns.net as Proxy you'd need a port forward on 5060 (assuming you use TSIP, for SIPS it'd be 5061 as far as I remember) to your PBX and it should work.
I tried the domain-name based SIP registration to a PBX with an alpha v12r1 android, but I believe it should work with v11r2 the same way. You can even use a non-standard port (which I would recommend to fool SIP port scanners) and use mydomain.ddns.net:yourport.
Keep in mind that opening SIP registrations to the public is dangerous.
Regards, Christoph