I was after a cheap and cheerful SIP phone to use with my Asterisk server. Right now, by which I mean February 2013, eBay turns up a regular supply of a cheap (£15.99 plus post) beast called the Netphone KE1020A.
So I took the plunge. But I had a bit of trouble getting the thing working and ended up having to connect my PC into the PC Out Ethernet socket and use Wireshark to capture the phone IP traffic and see what was going wrong. This page is in case anyone else struggles with the same problem.
My box arrived with a sticker warning me NOT to upgrade the firmware from the v4.32.06 installed. If you do, it will only let you use the pre-programmed SIP provider. So, when the phone starts up, and invites you to upgrade, hit the Esc key!
If anyone has firmware files for this phone, I'd appreciate a copy. I've already had to yank the power to stop an accidental upgrade. It would be good to have a way back if this happens again.
When the phone starts, it connects via FTP to update.konceptusa.com and logs in as user KE_SIP password voip7788. This directory contains Koncept.bin and Koncept_4.34.05.bin. I assume this is the later firmware the phone tries to install.
You can do some configuration through the phone setup menu, but the easy way is to allow the phone to boot and get a DHCP address, and then point a web browser at that address. You will be asked for an access code. I think the default is 1234. If it isn't, it is easy to set your own using the procedure described in the manual (SET/OK, DOWN to Advced Settings, SET/OK to show Access code and SET/OK again to enter a new one)).
Most of the configuration is straightforward, but I was puzzled by the field named IP Phone no. On saving the settings, the phone rebooted and said 'Wait login'. And then just sat there.
On using Wireshark to view the phone IP traffic, I saw the phone send a DNS request for the Asterisk server to my router, but for some reason my router never replied. I worked around this by changing the phone settings to use a static IP, and specifying Google Public DNS (8.8.8.8 and 8.8.4.4) as the DNS servers. The phone was lucky enough to get a reply from them. So if you've tried every combination of settings you can think of, and the phone won't log into your server, try that. Google turned up reports from people who found their phone worked on a friend's broadband setup but not on theirs. I think this is why. Wireshark showed no difference I could see in the DNS requests to my router from the phone and from my PC, except that those from the PC were answered. Very mysterious.
I then found that the field IP Phone no. is used by the phone as the login. This had confused me. Once I corrected it, the phone connected and started working.
So, here's the settings I used to connect to my Asterisk server. The phone is connected as extension 302.
SIP server: sip.myasterisk.com SIP port: 5060 User ID: 302 Password: mypassword IP Phone No.: 302
Note with a normal Asterisk setup, you need to enter the extension as BOTH the user ID and the phone number. That's because although they are technically different things, normal Asterisk practice is to use the extension as the username. Plenty of SIP software will invite you to enter only User name and Password, possibly allowing an Authorisation username somewhere in the advanced settings.