We have a set of DT-730 IP phones, which we use with an NEC SV8100 PBX. We're looking at using a few of these with an Asterisk system.
Out of the box, the DT700 series phones won't talk "open SIP", and so they won't work with Asterisk. But the DT700 resource manual does mention that the phones can be converted from NECI firmware to Standard SIP Firmware. (Here's the document):https://goo.gl/6IsC2
The problem is, I have no idea how to find the standard SIP Firmware (itlissipv.tgz). It doesn't seem to be on any of NEC's support sites. The only way that it looks like it can be obtained, is by connecting the DT730 up to an NEC Sphericall system. Because Sphericall supports open SIP, it will re-flash the phone automatically.
I suppose at that point the firmware could be downloaded from the phone using NECs IP Phone Manager software.
Does anyone have any pointers or suggestions on how we can convert the phones? We know that it's possible - it's just a question of getting the right firmware!
Thanks in advance,