There is probably a load of Ipecs phone systems that need updated software. These systems probably work just fine but could be vulnerable to hacking and could also benefit from improvements made to the software. While the LG Ericsson Ipecs system has just hit the end of its life, you can still get more life out of the old system by bringing it to the latest version.
There were also some issues with phones not coming up after reboot, so you can also benefit from updating your handset and other module gateway software.
Many of these systems were sold by the big carriers here in Australia, and they are not exactly proactive in follow-up and keeping your system up to date.
Some of the earlier software is very susceptible to a heartbleed vulnerability. This bug can leave you wide open to hackers stealing your information, and in the case of your PABX system, they could log in, ghost your account and make unauthorised calls. I have heard of examples where phone systems have been hacked for over $10,000 dollars of calls in a weekend.
These are all very good reasons to get your system evaluated for an update to get the best security and performance from your old phone system.