Nec SV8100 Phone System and GS728TP

I need to set it on both the Netgear Switch GS748Tv3 going over a EnGenius ENH500 Wireless Bridge in the WDS Bridge mode to another building with a Netgear Switch GS728TP v3 to pass traffic to and from my NEC SV8100 Digital and VoIP Phone System. The issue is that something in the switches we think are blocking the SIP packets maybe because we get NT_LLDP-N-LLDP_TRAP: LLDP status: entry deleted on ifindex g9 and the NEC VoIP Phones Log off randomly throughout the day. We changed the Nec SV8100 Phone System Subscribe Expiry time from 3600 (default) to 180 and all are issues go away but this is only a work around because it causes excessive load on the phone systems CPU. We were told to setup QOS and use DSCP and set IP
Precedence at level 5. We did we think but with the phone system set back to default the VoIP Phones randomly disconnect again. We do not have any Vlans setup and with my limited knowledge of them I might make the issue worse. Please anyone have any suggestions?