Temporal variation and endpoint sensitivity in SICA Interconnection measurements: An exploratory RIPE Atlas study

This paper presents an exploratory study of temporal latency variation, reciprocal measurement differences, and endpoint sensitivity using RIPE Atlas traceroute measurements among selected endpoints in seven countries of the Central American Integration System (SICA). The study examines how multi-day latency summaries can obscure changes in round-trip time (RTT) occurring within specific observation periods. It also investigates differences between reciprocal measurements and evaluates how the selection of observation nodes influences regional summary statistics. The findings identify two exploratory episodes involving simultaneous RTT increases across multiple measurement directions. They also reveal persistent reciprocal differences associated with a selected Costa Rican anchor that were not reproduced by two additional anchors in the same country. These observations demonstrate endpoint sensitivity without establishing the underlying physical or routing mechanisms. Through a leave-one-node-out sensitivity analysis, the study further demonstrates how aggregated latency indicators depend on the endpoints included in the sample. The results highlight the importance of explicitly reporting observation periods, measurement directions, and endpoint selection when interpreting cross-country connectivity measurements. The study provides reproducible empirical evidence and methodological considerations for future research on regional Internet interconnection, without claiming nationally representative network performance.