Feature request: in application dyndns->ip resolving for Fritz!Box registrar

[GoogleCodeExporter]

When trying to connect to a Fritz!Box(*) SIP Registrar from outside of the
boxes (W)LAN using a dyndns-address it does not work.

If you use the external IP-address of the box when connecting (the address
the dyndns-address is resolved to), everything is fine.

So right now - if you wish to connect to a Fritz!Box from outside you have
to do a nslookup for example using this WebApp:
http://www.i.voixdargent.com/reseaux/nslookup.php and put the resolved IP
address in Siphone settings as "Server".
This works fine - but it would be great, if this step (resolving hostname
to ip address an from now on only use the ip address for contacting sip
registrar) could be automized.

This is not an generic iphone networking dns problem, but an issue of the
fritz!box where the ip approach is a good workaround.

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(*) A Fritz!Box is a DSL/WLAN/VOIP/ISDN etc. all in one box.

Original issue reported on code.google.com by o.nauroth@gmail.com on 10 Jul 2009 at 2:54

[GoogleCodeExporter]

I just release beta version of Siphon on : 
http://code.google.com/p/siphon/downloads/list

You can define dns to use. I think it should resolve this issue.
Be careful, because if you define DNS server, Siphon try to use it and they 
don't use
iPhone dns.

Original comment by samuelv0...@gmail.com on 7 Nov 2009 at 11:45

[GoogleCodeExporter]

Samuel,

thanks for the beta, but DNS is not the issue, as mentioned in the feature 
request. 

Nevertheless I tested Your beta. It works fine, but the issue is not solved - 
with or without specifying a DNS 
Server.

I can't tell exactly on a networking level, what the problem is, but the 
Fritz!Box has to be connected by using 
the IP-Adress, not the FQDN. I will try to describe again:

Lets assume, the Fritz!Box is registered as "fritz.dyndns.org" an this is 
resolved to the outside IP-Adress of 
the Fritz!Box, let's say 12.34.56.78

Trying to use "fritz.dyndns.org" as the registrar/server in the Siphon settings 
does not work from outside, 
while using "12.34.56.78" as the registrar/server does work fine, although it 
is the correct ip address, 
"fritz.dyndns.org" is actually resolved to.
The Fritz!Box just does not like to be called by it's outside-name - it needs 
to be called by it's IP-adresss, if 
you want to connect to it's registrar from outside.
It's the same problem with all other SIP clients, not only on iPhone, but on 
PC/Mac as well; one of them has 
exactly the workaround that would be needed for Siphon too.

It's some sort of protection, since the Fritz!Box is mainly intended to be used 
as a registrar for IP Phones at 
home. Connecting internally using "fritz.box" (the internal name) or 
192.168.178.1 (local ip) both works fine.

The problem with just entering the external IP as the registrar - and leave it 
that way - is, that I do not have a 
static IP address at home, but a dynamic one, that changes after every 
reconnect to my providers network (at 
least every 24h). That's why I use the WebApp I mentioned in the feature 
request everytime I have trouble 
connecting, adjust the IP-Adress in the settings, launch Siphon again.

If you could query the (iPhone) DNS Server at startup, asking for the ip-Adress 
of the Server/Registrar 
specified in Siphon Settings, and after that time only use the resolved 
ip-Adress for all connections to the 
Fritz!Box, everything should be fine.

If you need further informations, just let me know.

Thanks for Your efforts,

Oliver

Original comment by o.nauroth@gmail.com on 16 Nov 2009 at 10:47