Problem resolved: It appears as though it was a phone system configuration issue after all. Nothing to do with the router.

Hello. Does the ER7212PC need to be configured to allow voice traffic when VoIP phones are installed? Aside from forwarding the necessary ports and disabling SIP ALG I'm unsure if anything else needs...

Hello. Can the ER7212PC be configured to use both a Client-to-Site VPN and a Site-to-Site VPN at the same time using multiple VPN policies? The Client-to-Site VPN has been in use for about a year now...

@Loycelover- Thank you for the response. It is L2TP/IPsec and I'm thinking it was likely an internet drop. I can't anything else that would cause this.

Hello. I was testing the length of time an L2TP VPN session would stay connected on my ER7212PC device. The connection lasted just over 7.5 hours before disconnecting. In Event Viewer the message was...

@Clive_A Thank you for the follow up. I am at a loss now lol. I will have to look into it more next week. I appreciate your help with providing a solution.