WL500gx: VoIP with DHCP works, static IP not

[tscoreninja]

Dear Forum members,

I have set up my WL-500g deluxe with a Sipura SPA 2000 voice over IP adapter attached on a LAN port, which has two phone lines configured with two providers (sipgate.de, dus.net). If I configure the SPA to use DHCP to get its IP address, everything works fine (using STUN, no port-forwarding). If I configure the sipura to a static IP address (successfully, as I can reach the administration interface using this IP), both SIP accounts cannot register to the provider. Pretty much default setup otherwise. Firmware is stock Asus 1.8.2.1. Why does this make a difference? Any ideas or known bugs in the Asus firmware? If so, is this fixed in Olegs firmwares?
Next, I will play around with port-forwarding etc, but I still do not see why the one setup works and the other doesn't...
(I definitely want to move to static IPs for my own equipment, and limit ports/services for DHCP clients, to be able to leave my network open).

thanks a lot in advance,
TSCoreNinja

[barsju]

Have you tried to use dhcp but assign the sippura a static ip based on mac-address? In other words sippura is set up to use dhcp, but it gets the same ip from wl500g everytime. Or is that whats not working?

S.

[tscoreninja]

Have you tried to use dhcp but assign the sippura a static ip based on mac-address?
Not yet, good point, will try that out tonight and report what happens.
However, I am really puzzled by the difference, because I do not see how the negotiation of the IP should affect the operation once the router and ATA have agreed upon an IP. The longer I think about it, the less it seems to make sense. Or am I missing something?
Thanks for the answer,
TSCoreNinja

[tscoreninja]

Sorry to have bothered you, problem is solved. I overlooked that if I assign IPs manually, the DNS server will also not be assigned automatically. I guess it helps to enter the DNS server manuallly then... Brown paperbag over my head...
TSCoreNinja