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Wed, October 12 - I learn that Sunrise, my cellphone provider, allows me to manage every aspect of my account on the internet. A password is sent to my phone upon request and I start poking around the site rightaway. An item labeled "sunrise webphone" catches my attention. They offer full-fledged VoIP & POTS telephone service for 5.90/month, 2 hours included, free from VoIP to VoIP and I get to choose the phone number. I compare it to my 25.00/month, no free minutes included, expensive Swisscom landline. The decision to place an order is easy.
Fri, October 14 - the letter with my password arrives. I start playing around with X-Lite. I can make calls, but not be called. I hope this will be better with the equipment they promised to send me.
Mon, Ocober 17 - the "starter package" arrives. The shelf of electronic gadgets in my room is extended by a small black box labeled Zyxel Prestige 2302R, a so-called ATA (Analog Telephone Adapter) sitting on the server next to the UPS. This box is pretty cool but somewhat stupid, it expects to be connected directly to the internet and offers mediocre NAT/firewall services with private IPs to all other devices. I just know that my server doesn't like the idea of sitting behind this box, so I try to add it to my LAN. I quickly find out that a VoIP device behind a firewall and a NAT server is a nightmare to configure.
I set the NAT server to forward port 5060/UDP, which is used for SIP, to the ATA. The device registers, both inbound and outbound calls work. Crystal clear communication even with eMule, a large download and a busy web server fighting over the available bandwith with the VoIP app. I'm happy!
Tue, Oct 18 - The phone is dead. The ATA says it can't register. My network sniffer says it doesn't even attempt to connect. I play with the settings for half an hour before I give up and reset the darn thing. I enter my username and password and it works again. Happy!
Tue, Oct 18, later - The phone is dead again. I try to fix it for a couple of hours. When I reset & reconfigure it, it works for a few minutes and then it can't connect anymore. The latest firmware update they offer is one minor version behind the one on my device. I'm pissed off.
Wed, Oct 19 - I learn that RTP, the actual protocol used to transmit the conversation, may use any UDP port from 10000-50000 (quite the modest protocol). I inform the NAT server of that fact.
I find out that when I give that Zyxel thing a static IP address it goes crazy after a while, and when it obtains the exact same data over DHCP, it works. They could have mentioned that in their manual!
The darn thing still announces its private IP th the SIP proxy, but at least the proxy seems to be smart enough to ignore it.
Anyway, phone works, I'm happy!
Now to talk all my friends into getting VoIP so I can chat with them for free.
Consider yourself hugged.
This post was edited by null on Oct 27, 2005.