Hi,
we have tested OCS 2007 (pre-R2) with Alcatel-Lucent OXE R8. It works perfectly.
- OCS->Mediation->PBX
- PBX->Mediation->OCS
- OCS->Mediation->PBX->PSTN
- PSTN->PBX->Mediation->OCS
A detailed write-up here: http://www.appliednethellas.com
Basically, the mediation server needs to be setup as an external gateway to the alcatel PBX. R8 lets you do this. This was not posible in R7. On the PBX side you need the correct codecs and some minor tweaks. On the OCS side you need the corect normalization rules in OCS for the connection to work.
After everything is correctly setup, we see no technical issues. Cost on the other hand may become an issue. Microsoft OCS CAL licenses for enterprise voice are more expensive than the PBX+user licenses... The OCS telephone sets (if you decide to use them) are even more expensive.