Now THIS could be fun :-)

[pepax]

Model UP-100
Compliant Softphone X-Lite, Net2Phone, Skype, MSN Messenger, X-PRO, eyeBeam

X-Pro | Business-class SIP Softphone

So I guess we only need a Linux SIP user agent compiled for mipsel (and the appropriate driver for the phone, if it isn't already in the firmware). I couldn't find any more details about this phone, its driver/utility is not on the Planet's homepage yet.

[Pirat]

Why didnt use this?? -> www.sipura.com

[MAV]

now i use X-lite on my desktop.
I want use only wl-500g+usb phone.
( I think than any hardware ip-phone like MicroNet SP5100 will work fine)
May be embed Open Phone H.323 http://www.openh323.org/

[Pirat]

But h323 != SIP

[MAV]

But h323 != SIP

I know about it.
I dreams thats somewhere SIP opensourse enable (like http://www.asterisk.org/ )