Where does ingress collide?

In observational astronomy ingress is the phase in which one body begins to pass in front of or behind another, the interval between first and second contact in a transit, eclipse or occultation; its timing and duration constrain sizes and limb geometry, as Morris and colleagues show in measuring exoplanet radii from ingress and egress durations. The referent is a contact phase in a celestial alignment. Contrast the network-engineering meaning, where ingress is traffic entering a domain.[1]

Unit

One ingress, measured as a duration (minutes) between contacts.

Recovery means

Time the interval from first to second contact of the two disks.

Measured by

Photometric light-curve timing of the contact points.

In network engineering ingress denotes traffic entering an administrative domain, and ingress filtering is the practice of validating or blocking such traffic at the boundary to defend against address spoofing and distributed denial-of-service, as in Du and Nakao's work on egress and ingress filtering. The referent is directional traffic at a network boundary. It shares only the Latin ingressus ('entry') with the astronomical contact phase.[2]

Unit

One ingress interface or flow, measured in traffic rate (packets/s).

Recovery means

Identify the boundary interface where external traffic enters the domain.

Measured by

Traffic monitoring and packet filtering at domain edges.