Is Rj45 ethernet the same as PARTNER phone sytem cabling?
There’s lots of posts out there on message boards that have people looking for this information (and it not being in the documentation for the system), but this USENET post both states that AT&T (who Avaya was spun off from) always used straight-through CAT-5 patch cables (which would indeed be the same as your regular old Ethernet cables). The post also has support numbers for Avaya so that you can confirm. There’s no technical reason why this couldn’t be the case, so chances are that you’re fine.