Internet-Security.com UDP port 5068 details

UDP 5068 is used by many SIP endpoints as an alternate local SIP signaling port.
Yealink IP phones (e.g., T4x/T5x series) default the local SIP port per account as 5060, 5062, 5064, 5066, 5068, 5070—so Account 5 listens on UDP 5068.
Grandstream IP phones (e.g., GXP and GRP series) use the same pattern, with Account 5 defaulting to UDP 5068 for SIP signaling.
In real deployments (hosted PBX/VoIP), these defaults are often left in place, so phones register and receive SIP messages on UDP 5068.

UDP 5068