[SIPForum-discussion] Windows Mobile 6 SIP differences

[Steve]

I wonder if any of you are using or working with WM6 dual mode mobile phones.

I have been performing some compatibility studies with devices and our
PABX and found to my surprise that they don't all work the same. When
I say the same find there are hardware differences like voice from
speaker rather than the ear peace. I'm more interested in the
difference in SIP messages.

The iPAQ 514 and the HTCS710 have similar methods to transfer but not
quite the same. They both attempt transfer using the REFER (without
INVITE, that our system doesn't support) but there is a method to get
around this, but only on the iPAQ.

What baffles me is that both WM6 phones have the same RTC 1.5.5374 so
at what point do they start to differ?

Any ideas are welcome?